Diphenhydramine interactions

Diphenhydramine (Benadryl, ZzzQuil, Sominex), an antihistamine has 213 documented interactions across the FDA labels and fact sheets we index: 60 major, 126 moderate, 26 minor, and 1 where a label reports no significant interaction. Each entry below quotes the sentence behind it. This drug page is a starting point, not a verdict for your situation.

Major interactions (60)

  • AclidiniumanticholinergicMajor

    Avoid administrations of TUDORZA PRESSAIR with other anticholinergic-containing drugs. (Aclidinium label, Drug interactions)

  • AlcoholAlcoholMajor

    Combining alcohol with sedating medicines (opioids, benzodiazepines, sleep medicines, muscle relaxants) can cause dangerous drowsiness, slowed breathing, and overdose. (NIAAA, Harmful Interactions: Mixing Alcohol with Medicines)

  • AlprazolambenzodiazepineMajor

    • Effects on Driving and Operating Machinery: Patients receiving • alprazolam XR should be cautioned against operating machinery or driving a motor vehicle, as well as avoiding concomitant use of alcohol and other central nervous system (CNS) depressant drugs. (Alprazolam label, Warnings and precautions)

  • If serotonin syndrome occurs, discontinue ADDERALL XR and the CYP2D6 inhibitor [see Warnings and Precautions ( 5.8 ), Overdosage ( 10 )] . (Amphetamine and dextroamphetamine label, Drug interactions)

  • BuprenorphineopioidMajor

    Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Buprenorphine label, Boxed warning)

  • ButorphanolopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Butorphanol label, Boxed warning)

  • CetirizineantihistamineMajor

    Avoid concurrent use of QUZYTTIR with alcohol or other CNS depressants because additional reduction in alertness and additional impairment of CNS performance may occur. (Cetirizine label, Warnings and precautions)

  • CiprofloxacinfluoroquinoloneMajor

    Table 8: Drugs That are Affected by and Affecting Ciprofloxacin Drugs That are Affected by Ciprofloxacin Drug(s) Recommendation Comments Tizanidine Contraindicated Concomitant administration of tizanidine and ciprofloxacin is contraindicated due to the potentiation of hypotensive and sedative effects of tizanidine [see Contraindications ( 4.2 )]. (Ciprofloxacin label, Drug interactions)

  • Clonidinealpha-adrenergic agonistMajor

    Avoid use with other central nervous system (CNS) depressants ( 5.3 ) (Clonidine label, Warnings and precautions)

  • ClozapineantipsychoticMajor

    When possible, avoid concomitant use, with other anticholinergic medications because the risk for anticholinergic toxicity or severe gastrointestinal adverse reactions is increased [see Warnings and Precautions ( 5.7 ), Drug Interactions ( 7.1 )]. (Clozapine label, Warnings and precautions)

  • CodeineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Codeine label, Boxed warning)

  • Cyclobenzaprinemuscle relaxantMajor

    Based on its structural similarity to TCAs, concomitant use of TONMYA with: MAO inhibitors may be life-threatening [see Contraindications (4) ] , Alcohol, barbiturates, and other CNS depressants may increase the risk of adverse reactions associated with these drugs, Tramadol may increase the seizure risk, Guanethidine or other similar acting drugs may block the… (Cyclobenzaprine label, Drug interactions)

  • DimenhydrinateantihistamineMajor

    CONTRAINDICATIONS Neonates and patients with a history of hypersensitivity to dimenhydrinate or its components (diphenhydramine or 8-chlorotheophylline) should not be treated with dimenhydrinate. (Dimenhydrinate label, Contraindications)

  • DoxylamineantihistamineMajor

    …glaucoma • trouble urinating due to an enlarged prostate gland Ask a doctor or pharmacist before use if you are taking • a sedative or any other sleep-aid • tranquilizers • any other antihistamines • any other drugs When using this product • avoid alcoholic beverages • do not drive a motor vehicle or operate machinery • take only at bedtime Stop use and ask a doctor… (Doxylamine label, Warnings)

  • Eszopiclonesedative-hypnoticMajor

    The use of LUNESTA with other sedative-hypnotics at bedtime or the middle of the night is not recommended. (Eszopiclone label, Warnings and precautions)

  • FentanylopioidMajor

    • Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Fentanyl label, Boxed warning)

  • Intervention Concomitant use of anticholinergic drugs with GVOKE VialDx is not recommended. (Glucagon label, Drug interactions)

  • GlycopyrrolateanticholinergicMajor

    • Other Conditions Exacerbated by Anticholinergic Adverse Reactions : Use is not recommended in patients with autonomic neuropathy, hyperthyroidism, cardiac disease, hiatal hernia, etc. (Glycopyrrolate label, Warnings and precautions)

  • Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Hydrocodone and acetaminophen label, Boxed warning)

  • HydromorphoneopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death . (Hydromorphone label, Boxed warning)

  • HydroxyzineantihistamineMajor

    Rarely, cardiac arrests and death have been reported in association with the combined use of hydroxyzine hydrochloride intramuscularly and other CNS depressants. (Hydroxyzine label, Precautions)

  • IpratropiumanticholinergicMajor

    Avoid administration of ATROVENT HFA with other anticholinergic-containing drugs ( 7.1 ) (Ipratropium label, Drug interactions)

  • Itraconazoleazole antifungalMajor

    Co-administration with eliglustat is contraindicated in poor or intermediate metabolizers of CYP2D6 and in subjects taking strong or moderate CYP2D6 inhibitors. (Itraconazole label, Boxed warning)

  • KetamineCNS depressantMajor

    Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic. (Diphenhydramine label, Contraindications)

  • Ketoconazoleazole antifungalMajor

    This may potentiate and prolong hypnotic and sedative effects, especially with repeated dosing or chronic administration of these agents. (Ketoconazole label, Contraindications)

  • LevocetirizineantihistamineMajor

    Avoid concurrent use of alcohol or other central nervous system depressants with XYZAL. (Levocetirizine label, Warnings and precautions)

  • LevorphanolopioidMajor

    Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Levorphanol label, Boxed warning)

  • Lidocainelocal anestheticMajor

    Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic. (Diphenhydramine label, Contraindications)

  • Lidocaine and prilocainelocal anestheticMajor

    Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic. (Diphenhydramine label, Contraindications)

  • LisdexamfetamineCNS stimulantMajor

    If serotonin syndrome occurs, discontinue lisdexamfetamine dimesylate and the CYP2D6 inhibitor [see Warnings and Precautions (5.7) and Overdosage (10) ] . (Lisdexamfetamine label, Drug interactions)

  • LorazepambenzodiazepineMajor

    Caution patients receiving LOREEV XR against operating machinery or driving a motor vehicle as well to avoid the concomitant use of alcohol and other CNS depressant drugs during treatment ( 5.4 , 7 ) (Lorazepam label, Warnings and precautions)

  • MeperidineopioidMajor

    Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Meperidine label, Boxed warning)

  • MethadoneopioidMajor

    Managing Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, is a risk factor for respiratory depression and death [see Warnings and Precautions ( 5.2 )]. (Methadone label, Boxed warning)

  • Metoclopramidedopamine antagonistMajor

    Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, malignant hyperthermia, drug fever, serotonin syndrome, and primary central nervous system pathology. (Metoclopramide label, Warnings and precautions)

  • Metoprololbeta blockerMajor

    CYP2D6 Inhibitors Monitor patients closely when the combination use of CYP2D6 inhibitor and metoprolol cannot be avoided. (Metoprolol label, Drug interactions)

  • MidazolambenzodiazepineMajor

    WARNING: PERSONNEL AND EQUIPMENT FOR MONITORING AND RESUSCITATION, AND RISKS FROM CONCOMITANT USE WITH OPIOID ANALGESICS AND OTHER SEDATIVE-HYPNOTICS Personnel and Equipment for Monitoring and ResuscitationOnly personnel trained in the administration of procedural sedation, and not involved in the conduct of the diagnostic or therapeutic procedure, should administer… (Midazolam label, Boxed warning)

  • MoexiprilACE inhibitorMajor

    None of the cases were considered life-threatening and all resolved either without treatment or with medication (antihistamines or glucocorticoids). (Moexipril label, Warnings)

  • MorphineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Morphine label, Boxed warning)

  • NalbuphineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Nalbuphine label, Boxed warning)

  • …(selective blocker of Na v 1.8 sodium channels): suzetrigine • Opioid antagonists: naloxegol • PDE5 inhibitor: sildenafil (Revatio ® ) when used for pulmonary arterial hypertension (PAH) • Sedative/hypnotics: triazolam, oral midazolam • Serotonin receptor 1A agonist/serotonin receptor 2A antagonist: flibanserin • Vasopressin receptor antagonists: tolvaptan ➢ Drugs that… (Nirmatrelvir and ritonavir label, Contraindications)

  • OliceridineopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Oliceridine label, Boxed warning)

  • OlopatadineantihistamineMajor

    Avoid concurrent use of alcohol or other central nervous system depressants with olopatadine hydrochloride nasal spray ( 5.2 ). (Olopatadine label, Warnings and precautions)

  • OxycodoneopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Oxycodone label, Boxed warning)

  • …LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; NEONATAL OPIOID WITHDRAWAL SYNDROME; CYTOCHROME P450 3A4 INTERACTION; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Addiction, Abuse, and Misuse Oxycodone hydrochloride tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to… (Oxycodone and acetaminophen label, Boxed warning)

  • OxymorphoneopioidMajor

    Risks From Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Oxymorphone label, Boxed warning)

  • …MITIGATION STRATEGY (REMS); LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; NEONATAL OPIOID WITHDRAWAL SYNDROME; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Addiction, Abuse, and Misuse Pentazocine and Naloxone Tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to… (Pentazocine and naloxone label, Boxed warning)

  • PhenelzineMAO inhibitorMajor

    Phenelzine sulfate should not be used in combination with dextromethorphan or with CNS depressants such as alcohol and certain narcotics. (Phenelzine label, Contraindications)

  • PitolisantQT-prolonging drugMajor

    Prevention or Management: Avoid centrally acting H1 receptor antagonists. (Pitolisant label, Drug interactions)

  • PropofolCNS depressantMajor

    Use as a Local Anesthetic Because of the risk of local necrosis, this drug should not be used as a local anesthetic. (Diphenhydramine label, Contraindications)

  • RitonavirantiretroviralMajor

    WARNING: DRUG-DRUG INTERACTIONS LEADING TO POTENTIALLY SERIOUS AND/OR LIFE THREATENING REACTIONS Co-administration of NORVIR with several classes of drugs including sedative hypnotics, antiarrhythmics, or ergot alkaloid preparations may result in potentially serious and/or life-threatening adverse events due to possible effects of NORVIR on the hepatic metabolism… (Ritonavir label, Boxed warning)

  • Rivastigminecholinesterase inhibitorMajor

    Concomitant use with metoclopramide, beta-blockers, or cholinomimetic and anticholinergic drugs is not recommended ( 7.1 , 7.2 , 7.3 ) (Rivastigmine label, Drug interactions)

  • Sodium oxybateCNS depressantMajor

    Abuse or misuse of illicit GHB, either alone or in combination with other CNS depressants, is associated with CNS adverse reactions, including seizure, respiratory depression, decreases in the level of consciousness, coma, and death [see Warnings and Precautions ( 5.2 )]. (Sodium oxybate label, Boxed warning)

  • TapentadolopioidMajor

    Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Tapentadol label, Boxed warning)

  • TiotropiumanticholinergicMajor

    Avoid administration of SPIRIVA RESPIMAT with other anticholinergic-containing drugs. (Tiotropium label, Drug interactions)

  • TramadolopioidMajor

    Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. (Tramadol label, Boxed warning)

  • TranylcypromineMAO inhibitorMajor

    These medicines are in some cold, hay fever or weight-loss medicines. sympathomimetic herbal medicines or dietary supplements antihistamines (allergy medicines) triptans buspirone carbamazepine dextromethorphan dopamine hydroxytryptophan and tryptophan levodopa and methyldopa meperidine rasagline resperine s-adenosyl-L-methionine (SAM-e) tapentadol tetrabenazin… (Tranylcypromine label, Boxed warning)

  • TriazolambenzodiazepineMajor

    • Effects on Driving and Operating Heavy Machinery : Patients receiving triazolam should be cautioned against driving or operating heavy machinery, as well as avoiding concomitant use with alcohol and other CNS depressant drugs. (Triazolam label, Warnings and precautions)

  • Umeclidinium and vilanterolanticholinergicMajor

    Avoid administration of Umeclidinium and Vilanterol ELLIPTA with other anticholinergic-containing drugs. (Umeclidinium and vilanterol label, Drug interactions)

  • Zaleplonsedative-hypnoticMajor

    The use of zaleplon with other sedative-hypnotics at bedtime or the middle of the night is not recommended (see ). (Zaleplon label, Warnings)

  • Zolpidemsedative-hypnoticMajor

    The use of Zolpidem Tartrate with other sedative-hypnotics (including other zolpidem products) at bedtime or the middle of the night is not recommended. (Zolpidem label, Warnings and precautions)

Moderate interactions (126)

  • AliskirenantihypertensiveModerate

    Patients who experience these effects, even without respiratory distress, require prolonged observation and appropriate monitoring measures since treatment with antihistamines and corticosteroids may not be sufficient to prevent respiratory involvement. (Aliskiren label, Warnings and precautions)

  • Allopurinolxanthine oxidase inhibitorModerate

    Inform patients also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. (Allopurinol label, Warnings and precautions)

  • AmantadineanticholinergicModerate

    Other Anticholinergic Drugs: Doses should be reduced if atropine-like effects occur ( 7.1 ) (Amantadine label, Drug interactions)

  • Amitriptylinetricyclic antidepressantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • AripiprazoleantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • AsenapineantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Atomoxetinenorepinephrine reuptake inhibitorModerate

    Strong CYP2D6 Inhibitors Prevention or Management With concomitant use of atomoxetine oral solution and a strong CYP2D6 inhibitor 1 , increase the titration interval [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3) ] . (Atomoxetine label, Drug interactions)

  • AzelastineantihistamineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Baclofenmuscle relaxantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Bictegravir, emtricitabine, and tenofovir alafenamideantiretroviralModerate

    Sedatives/Hypnotics: midazolam (oral) triazolam ↑ midazolam (oral) ↑ triazolam Use caution when midazolam or triazolam is concomitantly administered with BIXLENVO. (Bictegravir, emtricitabine, and tenofovir alafenamide label, Drug interactions)

  • BrexpiprazoleantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Brimonidinealpha-adrenergic agonistModerate

    Use with CNS depressants may result in an additive or potentiating effect. (Brimonidine label, Drug interactions)

  • BrivaracetamanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Budesonide and formoterolcorticosteroidModerate

    In clinical studies, concurrent administration of budesonide and formoterol fumarate dihydrate and other drugs, such as short-acting beta 2 -agonists, intranasal corticosteroids, and antihistamines/decongestants has not resulted in an increased frequency of adverse reactions. (Budesonide and formoterol label, Drug interactions)

  • Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Buspironeserotonergic drugModerate

    Triazolam/flurazepam: Coadministration of buspirone with either triazolam or flurazepam did not appear to prolong or intensify the sedative effects of either benzodiazepine. (Buspirone label, Drug interactions)

  • Butalbital, acetaminophen, and caffeinebarbiturateModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Cannabidiol (prescription)anticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • CarbamazepineanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • CariprazineantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Carisoprodolmuscle relaxantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Carvedilolbeta blockerModerate

    CYP2D6 Inhibitors and Poor Metabolizers Interactions of carvedilol with potent inhibitors of CYP2D6 isoenzyme (such as quinidine, fluoxetine, paroxetine, and propafenone) have not been studied, but these drugs would be expected to increase blood levels of the R(+) enantiomer of carvedilol [see Clinical Pharmacology (12.3) ]. (Carvedilol label, Drug interactions)

  • CenobamateanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ChlordiazepoxidebenzodiazepineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ChlorpheniramineantihistamineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ChlorpromazineantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ClobazambenzodiazepineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ClonazepambenzodiazepineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Dantrolenemuscle relaxantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Daridorexantsedative-hypnoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • DarifenacinanticholinergicModerate

    Darifenacin extended-release tablets, like other anticholinergic drugs, may decrease gastrointestinal motility and should be used with caution in patients with conditions such as severe constipation, ulcerative colitis, and myasthenia gravis. (Darifenacin label, Warnings and precautions)

  • DeutetrabenazineVMAT2 inhibitorModerate

    Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever, and primary central nervous system pathology. (Deutetrabenazine label, Warnings and precautions)

  • Dexmedetomidinealpha-adrenergic agonistModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • DiazepambenzodiazepineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • DicyclomineanticholinergicModerate

    Anticholinergic agents: may affect the gastrointestinal absorption of various drugs; may also increase certain actions or side effects of other anticholinergic drugs (7) (Dicyclomine label, Drug interactions)

  • Divalproex (valproate)anticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Dorzolamide and timololcarbonic anhydrase inhibitorModerate

    CYP2D6 inhibitors may potentiate systemic beta-blockade. (Dorzolamide and timolol label, Drug interactions)

  • Doxepintricyclic antidepressantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • DronabinolcannabinoidModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • DuloxetineSNRIModerate

    Similar effects would be expected with other potent CYP2D6 inhibitors (e.g., fluoxetine, quinidine) [see Warnings and Precautions ( 5.12 )] . (Duloxetine label, Drug interactions)

  • Dutasteride and tamsulosin5-alpha reductase inhibitorModerate

    Use caution in combination with moderate CYP3A4 inhibitors (e.g., erythromycin) or strong (e.g., paroxetine) or moderate CYP2D6 inhibitors, a combination of both CYP3A4 and CYP2D6 inhibitors, or known poor metabolizers of CYP2D6. (Dutasteride and tamsulosin label, Warnings and precautions)

  • EluxadolineopioidModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • EpinephrinesympathomimeticModerate

    …arrhythmias [see Warnings and Precautions (5.6) and Adverse Reactions (6) ]. β-blockers, such as propranolol Cyclopropane or halogenated hydrocarbon anesthetics, such as halothane Antihistamines Thyroid hormones Diuretics Cardiac glycosides, such as digitalis glycosides Quinidine Drugs potentiating hypokalemic effects of epinephrine • Potassium depleting diuretics… (Epinephrine label, Drug interactions)

  • EslicarbazepineanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • EthosuximideanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • FelbamateanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • FesoterodineanticholinergicModerate

    Urinary Retention in Adult Patients With Bladder Outlet Obstruction The use of Toviaz, like other antimuscarinic drugs, in patients with clinically significant bladder outlet obstruction, including patients with urinary retention, may result in further urinary retention and kidney injury. (Fesoterodine label, Warnings and precautions)

  • FlibanserinCNS depressantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • GabapentinanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Guanfacinealpha-adrenergic agonistModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • HaloperidolantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • IloperidoneantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ImatinibCYP3A4 inhibitorModerate

    In these instances, Gleevec was resumed at a dose lower than that at which the reaction occurred and some patients also received concomitant treatment with corticosteroids or antihistamines. (Imatinib label, Warnings and precautions)

  • InfliximabimmunosuppressantModerate

    Medications for the treatment of hypersensitivity reactions (e.g., acetaminophen, antihistamines, corticosteroids and/or epinephrine) should be available for immediate use in the event of a reaction [see Dosage and Administration (2.10) and Adverse Reactions (6.1) ] . (Infliximab label, Warnings and precautions)

  • IsoniazidantibioticModerate

    MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines. (Diphenhydramine label, Drug interactions)

  • LacosamideanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Lemborexantsedative-hypnoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • LevetiracetamanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • LinezolidantibioticModerate

    MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines. (Diphenhydramine label, Drug interactions)

  • Lisinopril and hydrochlorothiazideACE inhibitorModerate

    Even in those instances where swelling of only the tongue is involved, without respiratory distress, patients may require prolonged observation since treatment with antihistamines and corticosteroids may not be sufficient. (Lisinopril and hydrochlorothiazide label, Warnings)

  • Lofexidinealpha-adrenergic agonistModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • LumateperoneantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • LurasidoneantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • MeclizineantihistamineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Methocarbamolmuscle relaxantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Mirabegronbeta-adrenergic agonistModerate

    • Urinary Retention in Patients With Bladder Outlet Obstruction and in Patients Taking Muscarinic Antagonist Drugs for Overactive Bladder : Administer with caution in these patients because of risk of urinary retention. (Mirabegron label, Warnings and precautions)

  • MirtazapineantidepressantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Naloxoneopioid antagonistModerate

    WARNINGS AND PRECAUTIONS Risk of Recurrent Respiratory and CNS Depression : Due to the duration of action of naloxone relative to the opioid, respiratory and CNS depression may recur after the first dose of naloxone. (Naloxone label, Warnings and precautions)

  • Naltrexone and bupropionopioid antagonistModerate

    …malformation, central nervous system tumor or infection, or metabolic disorders (e.g., hypoglycemia, hyponatremia, severe hepatic impairment, and hypoxia) excessive use of alcohol or sedatives, addiction to cocaine or stimulants, or withdrawal from sedatives patients with diabetes treated with insulin and/or oral diabetic medications (sulfonylureas and meglitinides)… (Naltrexone and bupropion label, Warnings and precautions)

  • Nebivololbeta blockerModerate

    Use with CYP2D6 Inhibitors Nebivolol exposure increases with inhibition of CYP2D6 [see Drug Interactions ( 7 ) ] . (Nebivolol label, Warnings and precautions)

  • Nifedipinedihydropyridine calcium channel blockerModerate

    …diverticulosis, and inflammatory bowel disease), hypomotility disorders (e.g., constipation, gastroesophageal reflux disease, ileus, obesity, hypothyroidism, and diabetes) and concomitant medications (e.g., H 2 -histamine blockers, opiates, nonsteroidal anti-inflammatory drugs, laxatives, anticholinergic agents, levothyroxine, and neuromuscular blocking agents). (Nifedipine label, Warnings)

  • Nortriptylinetricyclic antidepressantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • OcrelizumabimmunosuppressantModerate

    In multiple sclerosis (MS) clinical trials, all adult and pediatric patients who were treated with OCREVUS received premedication with methylprednisolone (or an equivalent steroid), and may have also received an antihistamine (all pediatric patients) and/or an analgesic/antipyretic to reduce the risk of infusion reactions prior to each infusion. (Ocrelizumab label, Warnings and precautions)

  • OfloxacinfluoroquinoloneModerate

    Serious acute hypersensitivity reactions may require treatment with epinephrine and other resuscitative measures, including oxygen, intravenous fluids, antihistamines, corticosteroids, pressor amines, and airway management, as clinically indicated (see PRECAUTIONS and ADVERSE REACTIONS ). (Ofloxacin label, Warnings)

  • OlanzapineantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • OnabotulinumtoxinAneuromuscular blockerModerate

    Anticholinergic Drugs Use of anticholinergic drugs after administration of BOTOX may potentiate systemic anticholinergic effects. (OnabotulinumtoxinA label, Drug interactions)

  • OxcarbazepineanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • OxybutyninanticholinergicModerate

    Oxybutynin chloride extended-release tablets, like other anticholinergic drugs, may decrease gastrointestinal motility and should be used with caution in patients with conditions such as ulcerative colitis and intestinal atony. (Oxybutynin label, Warnings and precautions)

  • PaliperidoneantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ParoxetineSSRIModerate

    Cimetidine Increased plasma concentration of paroxetine Use caution if BRISDELLE is used concomitantly with other drugs that inhibit CYP2D6 (e.g., quinidine). (Paroxetine label, Drug interactions)

  • PerampanelanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • PhenobarbitalbarbiturateModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Phentermine and topiramateCNS stimulantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • PhenytoinanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Pilocarpinecholinergic agonistModerate

    These effects should be considered when anticholinergic properties may be contributing to the therapeutic effect of concomitant medication (e.g., atropine, inhaled ipratropium). (Pilocarpine label, Drug interactions)

  • PimavanserinantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Posaconazoleazole antifungalModerate

    Concomitant Use with Midazolam : Noxafil can prolong hypnotic/sedative effects. (Posaconazole label, Warnings and precautions)

  • Pramipexoledopamine agonistModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • PregabalinanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • PrimidoneanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ProchlorperazineantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • PromethazineantihistamineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Propranololbeta blockerModerate

    Impact of Other Drugs on Propranolol CYP2D6, CYP1A2 and CYP2C19 Inhibitors: CYP2D6 inhibitors (e.g. bupropion, fluoxetine, paroxetine, quinidine), CYP1A2 inhibitors (e.g., ciprofloxacin, enoxamine, fluvoxamine) and CYP2C19 inhibitors (e.g., fluconazole, fluvoxamine, ticlopidine) increase exposure to propranolol when co-administered with INNOPRAN XL. (Propranolol label, Drug interactions)

  • Pyridostigminecholinesterase inhibitorModerate

    Use with caution in persons with increased risk of anticholinergic reactions, such as persons with bronchial asthma, chronic obstructive pulmonary disease, bradycardia, cardiac arrhythmias, beta blocker treatment (increased risk of anticholinergic reactions). (Pyridostigmine label, Warnings and precautions)

  • QuetiapineantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Ramelteonsedative-hypnoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • RasagilineMAO inhibitorModerate

    MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines. (Diphenhydramine label, Drug interactions)

  • RisperidoneantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Ropiniroledopamine agonistModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • RufinamideanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ScopolamineanticholinergicModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • SelegilineMAO inhibitorModerate

    MAO inhibitors prolong and intensify the anticholinergic (drying) effects of antihistamines. (Diphenhydramine label, Drug interactions)

  • SolifenacinanticholinergicModerate

    Urinary Retention The use of Solifenacin succinate tablets, like other antimuscarinic drugs, in patients with clinically significant bladder outlet obstruction including patients with urinary retention, may result in further urinary retention and kidney injury. (Solifenacin label, Warnings and precautions)

  • Suvorexantsedative-hypnoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Tamsulosinalpha blockerModerate

    Use with caution in combination with moderate inhibitors of CYP3A4, with strong or moderate inhibitors of CYP2D6, in patients known to be CYP2D6 poor metabolizers, or in combination with other cytochrome P450 inhibitors. (Tamsulosin label, Warnings and precautions)

  • Tasimelteonsedative-hypnoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • TemazepambenzodiazepineModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • TetrabenazineVMAT2 inhibitorModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • TheophyllinemethylxanthineModerate

    25% increase Diazepam Benzodiazepines increase CNS concentrations of adenosine, a potent CNS depressant, while theophylline blocks adenosine receptors. (Theophylline label, Drug interactions)

  • TiagabineanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Timololbeta blockerModerate

    CYP2D6 Inhibitors Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with CYP2D6 inhibitors (e.g., quinidine) and timolol. (Timolol label, Drug interactions)

  • Tizanidinemuscle relaxantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • TopiramateanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • TrazodoneantidepressantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • TrihexyphenidylanticholinergicModerate

    Concurrent use of alcohol or other CNS depressants with trihexyphenidyl HCl may cause increased sedative effects. (Trihexyphenidyl label, Drug interactions)

  • TrospiumanticholinergicModerate

    Trospium chloride extended-release capsules, like other antimuscarinic agents, may decrease gastrointestinal motility and should be used with caution in patients with conditions such as ulcerative colitis, intestinal atony and myasthenia gravis. (Trospium label, Warnings and precautions)

  • ValbenazineVMAT2 inhibitorModerate

    For patients who are CYP2D6 poor metabolizers or are taking a strong CYP2D6 inhibitor, dose reduction may be necessary. (Valbenazine label, Warnings and precautions)

  • Valproic acidanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • VenlafaxineSNRIModerate

    Therefore, the potential exists for a drug interaction between drugs that inhibit CYP2D6-mediated metabolism of venlafaxine, reducing the metabolism of venlafaxine to ODV, resulting in increased plasma concentrations of venlafaxine and decreased concentrations of the active metabolite. (Venlafaxine label, Drug interactions)

  • Vibegronbeta-adrenergic agonistModerate

    Urinary Retention : Monitor for urinary retention, especially in patients with bladder outlet obstruction and also in patients taking muscarinic antagonist medications for OAB, in whom the risk of urinary retention may be greater. (Vibegron label, Warnings and precautions)

  • VigabatrinanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • Viloxazinenorepinephrine reuptake inhibitorModerate

    CYP2D6 Substrates Clinical Impact Viloxazine is a weak inhibitor of CYP2D6, and increases the exposure of CYP2D6 substrates when coadministered [see Clinical Pharmacology (12.3) ] . (Viloxazine label, Drug interactions)

  • Voriconazoleazole antifungalModerate

    Eszopiclone (CYP3A4 Inhibition) Not Studied In Vivo or In Vitro , but Drug Plasma Exposure Likely to be Increased which may Increase the Sedative Effect of Eszopiclone Dose reduction of eszopiclone is recommended. (Voriconazole label, Drug interactions)

  • VortioxetineantidepressantModerate

    • Strong inhibitors of CYP2D6: Reduce TRINTELLIX dose by half when coadministered ( 2.5 , 7.1 ). (Vortioxetine label, Drug interactions)

  • ZiprasidoneantipsychoticModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

  • ZonisamideanticonvulsantModerate

    Drug Interactions Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc). (Diphenhydramine label, Drug interactions)

Minor mentions (26)

  • BenazeprilACE inhibitorMinor

    Symptoms have not been relieved by antihistamines in these situations. (Benazepril label, Warnings and precautions)

  • BenztropineanticholinergicMinor

    When benztropine mesylate is given concomitantly with phenothiazines, haloperidol, or other drugs with anticholinergic or antidopaminergic activity, patients should be advised to report gastrointestinal complaints, fever or heat intolerance promptly. (Benztropine label, Warnings)

  • BupropionantidepressantMinor

    Additional predisposing conditions include diabetes mellitus treated with oral hypoglycemic drugs or insulin, use of anorectic drugs, excessive use of alcohol, use of benzodiazepines, sedatives/hypnotics, or opiates. (Bupropion label, Warnings and precautions)

  • CefadroxilcephalosporinMinor

    SERIOUS ACUTE HYPERSENSITIVITY REACTIONS MAY REQUIRE TREATMENT WITH EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, INTRAVENOUS FLUIDS, INTRAVENOUS ANTIHISTAMINES, CORTICOSTEROIDS, PRESSOR AMINES, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED. (Cefadroxil label, Warnings and precautions)

  • CefdinircephalosporinMinor

    SERIOUS ACUTE HYPERSENSITIVITY REACTIONS MAY REQUIRE TREATMENT WITH EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, INTRAVENOUS FLUIDS, INTRAVENOUS ANTIHISTAMINES, CORTICOSTEROIDS, PRESSOR AMINES, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED. (Cefdinir label, Warnings)

  • CefpodoximecephalosporinMinor

    SERIOUS ACUTE HYPERSENSITIVITY REACTIONS MAY REQUIRE TREATMENT WITH EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, INTRAVENOUS FLUIDS, INTRAVENOUS ANTIHISTAMINE, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED. (Cefpodoxime label, Warnings)

  • CelecoxibNSAIDMinor

    CYP2D6 substrates Clinical Impact: In vitro studies indicate that celecoxib, although not a substrate, is an inhibitor of CYP2D6. (Celecoxib label, Drug interactions)

  • Cevimelinecholinergic agonistMinor

    Cevimeline might interfere with desirable antimuscarinic effects of drugs used concomitantly. (Cevimeline label, Drug interactions)

  • Donepezilcholinesterase inhibitorMinor

    Cholinesterase inhibitors have the potential to interfere with the activity of anticholinergic medications ( 7.1 ) (Donepezil label, Drug interactions)

  • EnalaprilACE inhibitorMinor

    Symptoms have not been relieved by antihistamines in these situations. (Enalapril label, Warnings and precautions)

  • Epoetin alfaMinor

    The “gasping syndrome” is characterized by central nervous system (CNS) depression, metabolic acidosis, and gasping respirations. (Epoetin alfa label, Warnings and precautions)

  • Erythromycinmacrolide antibioticMinor

    Erythromycin has been reported to significantly alter the metabolism of the nonsedating antihistamines terfenadine and astemizole when taken concomitantly. (Erythromycin label, Drug interactions)

  • FluoxetineSSRIMinor

    Most patients improved promptly with discontinuation of fluoxetine and/or adjunctive treatment with antihistamines or steroids, and all patients experiencing these reactions were reported to recover completely. (Fluoxetine label, Warnings and precautions)

  • FluvoxamineSSRIMinor

    In vitro data suggest that fluvoxamine is a relatively weak inhibitor of CYP2D6. (Fluvoxamine label, Drug interactions)

  • Galantaminecholinesterase inhibitorMinor

    Potential to interfere with the activity of anticholinergic medications ( 7.1 ) (Galantamine label, Drug interactions)

  • HeparinanticoagulantMinor

    Other Interactions Digitalis, tetracyclines, nicotine, or antihistamines, or intravenous nitroglycerin may partially counteract the anticoagulant action of heparin sodium. (Heparin label, Drug interactions)

  • Antihistamines and/or aspirin have been used for most mild to moderate cases. (Ivermectin label, Warnings)

  • LevofloxacinfluoroquinoloneMinor

    Serious acute hypersensitivity reactions may require treatment with epinephrine and other resuscitative measures, including oxygen, intravenous fluids, antihistamines, corticosteroids, pressor amines, and airway management, as clinically indicated [see Adverse Reactions ( 6 ) and Patient Counseling Information ( 17 )] . (Levofloxacin label, Warnings and precautions)

  • LisinoprilACE inhibitorMinor

    Symptoms have not been relieved by antihistamines in these situations. (Lisinopril label, Warnings and precautions)

  • Prazosinalpha blockerMinor

    …to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout–allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol (see WARNINGS however),… (Prazosin label, Drug interactions)

  • QuinaprilACE inhibitorMinor

    In instances where swelling is confined to the face and lips, the condition generally resolves without treatment; antihistamines may be useful in relieving symptoms. (Quinapril label, Warnings)

  • RituximabimmunosuppressantMinor

    Premedicate patients with an antihistamine and acetaminophen prior to dosing. (Rituximab label, Warnings and precautions)

  • Sacubitril and valsartanangiotensin II receptor blocker (ARB)Minor

    In cases of confirmed angioedema where swelling has been confined to the face and lips, the condition has generally resolved without treatment, although antihistamines have been useful in relieving symptoms. (Sacubitril and valsartan label, Warnings and precautions)

  • SertralineSSRIMinor

    Drugs Metabolized by CYP2D6 Clinical Impact: Sertraline hydrochloride capsules are a CYP2D6 inhibitor [see Clinical Pharmacology ( 12.3 )] . (Sertraline label, Drug interactions)

  • Tamoxifenselective estrogen receptor modulatorMinor

    Strong Inhibitors of CYP2D6 The impact on the efficacy of tamoxifen with co-administration of strong CYP2D6 inhibitors (e.g., paroxetine) is not well established. (Tamoxifen label, Drug interactions)

  • TrandolaprilACE inhibitorMinor

    In instances where swelling is confined to the face and lips, the condition generally resolves without treatment; antihistamines may be useful in relieving symptoms. (Trandolapril label, Warnings)

No significant interaction reported (1)

  • Montelukastleukotriene receptor antagonistNo interaction

    …adjustment is needed when SINGULAIR is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, fexofenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3) ]. (Montelukast label, Drug interactions)

Check Diphenhydramine against everything you take. Add your full list; every pair is checked at once.

Open in the checker

Not medical advice. Severity reflects the label's wording, not your circumstances. A "major" flag can be routine under supervision and a "minor" one can matter at high doses. Ask a pharmacist.