Lidocaine interactions

Reserve the combination of amiodarone with other antiarrhythmic therapies that prolong the QTc to patients with life-threatening ventricular arrhythmias who are incompletely responsive to a single agent. (Amiodarone label, Warnings and precautions)

The use of SAPHRIS should be avoided in combination with other drugs known to prolong QTc including Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class 3 antiarrhythmics (e.g., amiodarone, sotalol), antipsychotic medications (e.g., ziprasidone, chlorpromazine, thioridazine), and antibiotics (e.g., gatifloxacin, moxifloxacin). (Asenapine label, Warnings and precautions)

QT Prolongation : Avoid clarithromycin tablets in patients with known QT prolongation or receiving drugs known to prolong the QT interval, ventricular arrhythmia ( torsades de pointes ), hypokalemia/hypomagnesemia, significant bradycardia, or taking Class IA or III antiarrhythmics ( 5.2 ) (Clarithromycin label, Warnings and precautions)

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)

Xylocaine with epinephrine solutions contain sodium metabisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. (Lidocaine label, Warnings)

Avoid co-administration of CONTEPO with drugs known to prolong the QT interval, such as class IA or class III antiarrhythmic medications, tricyclic antidepressants, macrolides, and antipsychotics [see Warnings and Precautions ( 5.2 )] . (Fosfomycin label, Drug interactions)

Antiarrhythmics Disopyramide Dofetilide Dronedarone Quinidine Contraindicated during and 2 weeks after TOLSURA treatment. (Itraconazole label, Drug interactions)

CONTRAINDICATIONS Lidocaine HCl is contraindicated in patients with a known history of hypersensitivity to local anesthetics of the amide type. (Lidocaine label, Contraindications)

Therefore, moxifloxacin should be avoided with Class IA and Class III antiarrhythmics [see Warnings and Precautions ( 5.6 ), Nonclinical Toxicology ( 13.2 ), and Patient Counseling Information ( 17 )]. (Moxifloxacin label, Drug interactions)

…concentrations are associated with serious and/or life-threatening reactions [see Drug Interactions (7.3) ] : • Alpha 1-adrenoreceptor antagonist: alfuzosin • Antianginal: ranolazine • Antiarrhythmic: amiodarone, dronedarone, flecainide, propafenone, quinidine • Anti-gout: colchicine (in patients with renal and/or hepatic impairment [see Table 2 , Drug Interactions… (Nirmatrelvir and ritonavir label, Contraindications)

One fatal case of anaphylaxis has been reported in which lidocaine was used as the diluent, and consequently the causal agent cannot be reliably determined. (OnabotulinumtoxinA label, Warnings and precautions)

• The applicability of the CAST results to other populations (e.g., those without recent myocardial infarction) or other antiarrhythmic drugs is uncertain, but at present, it is prudent to consider any IC antiarrhythmic to have a significant proarrhythmic risk in patients with structural heart disease. (Propafenone label, Boxed warning)

CONTRAINDICATIONS Lidocaine HCl is contraindicated in patients with a known history of hypersensitivity to local anesthetics of the amide type. (Lidocaine label, Contraindications)

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)

QT Prolongation : Patients with congenital QT syndrome or taking class IA or III antiarrhythmics should avoid using vardenafil hydrochloride tablets. (Vardenafil label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Amiodarone is an antiarrhythmic agent with negative chronotropic properties that may be additive to those seen with beta-blockers. (Atenolol label, Drug interactions)

…bradyarrhythmias or uncompensated heart failure • patients on drugs known to prolong the QT interval • patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, and in patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents. (Azithromycin label, Warnings and precautions)

Table 4 Drug Interactions with BIXLENVO Concomitant Drug Class: Drug Name Effect on Concentration ↑ = Increase, ↓ = Decrease Clinical Comment Antiarrhythmics: digoxin dofetilide ↑ digoxin ↑ dofetilide Use digoxin with caution and monitor digoxin therapeutic concentration. (Bictegravir, emtricitabine, and tenofovir alafenamide label, Drug interactions)

Bisoprolol fumarate and hydrochlorothiazide tablets should be used with caution when myocardial depressants or inhibitors of AV conduction, such as certain calcium antagonists (particularly of the phenylalkylamine [verapamil] and benzothiazepine [diltiazem] classes), or antiarrhythmic agents, such as disopyramide, are used concurrently. (Bisoprolol and hydrochlorothiazide label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs. (Cimetidine label, Drug interactions)

…syndrome, uncorrected electrolyte imbalance, such as hypokalemia or hypomagnesemia and cardiac disease, such as heart failure, myocardial infarction, or bradycardia), and patients receiving Class IA antiarrhythmic agents (quinidine, procainamide), or Class III antiarrhythmic agents (amiodarone, sotalol), tricyclic antidepressants, macrolides, and antipsychotics. (Ciprofloxacin label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

…droperidol, pimozide), specific antibiotics (e.g., erythromycin, gatifloxacin, moxifloxacin, sparfloxacin), Class 1A antiarrhythmic medications (e.g., quinidine, procainamide) or Class III antiarrhythmics (e.g., amiodarone, sotalol), and others (e.g., pentamidine, levomethadyl acetate, methadone, halofantrine, mefloquine, dolasetron mesylate, probucol or tacrolimus). (Clozapine label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Other Drugs with Anticholinergic Activity The following agents may increase certain actions or side effects of anticholinergic drugs including dicyclomine hydrochloride: amantadine, antiarrhythmic agents of Class I (e.g., quinidine), antihistamines, antipsychotic agents (e.g., phenothiazines), benzodiazepines, MAO inhibitors, narcotic analgesics (e.g., meperidine),… (Dicyclomine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Erythromycin should be avoided in patients with known prolongation of the QT interval, patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, and in patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents. (Erythromycin label, Warnings)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

…as: 1) clinically significant bradycardia (less than 50 bpm), 2) any clinically significant cardiac disease, including baseline prolonged QT interval, 3) treatment with Class 1 and Class III antiarrhythmics, 4) treatment with monoamine oxidase inhibitors (MAOI's), 5) concomitant treatment with other drug products known to prolong the QT interval and 6) electrolyte… (Fentanyl label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Other Anticholinergic Drugs There is potential for an additive interaction between glycopyrrolate and concomitantly used anticholinergic drugs (e.g., tricyclic antidepressants, anti-epileptics, class I antiarrhythmics, anti­-spasmodics, amantadine) resulting in increased anticholinergic adverse reactions. (Glycopyrrolate label, Drug interactions)

…FANAPT should be avoided in combination with other drugs that are known to prolong QTc including Class 1A (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications, antipsychotic medications (e.g., chlorpromazine, thioridazine), antibiotics (e.g., gatifloxacin, moxifloxacin), or any other class of medications known to… (Iloperidone label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Antiarrhythmics disopyramide, dofetilide, dronedarone, quinidine digoxin Disopyramide, dofetilide, dronedarone, quinidine: The potential increase in plasma concentrations of these drugs when coadministered with ketoconazole may increase the risk of serious cardiovascular events including QT prolongation. (Ketoconazole label, Drug interactions)

Levofloxacin should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalemia, and patients receiving Class IA (quinidine, procainamide), or Class III (amiodarone, sotalol) antiarrhythmic agents. (Levofloxacin label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Other Local Anesthetics or Agents Structurally Related to Local Anesthetics Oraqix should be used with caution in combination with dental injection anesthesia, other local anesthetics, or agents structurally related to local anesthetics, e.g., Class 1 antiarrhythmics such as tocainide and mexiletine, as the toxic effects of these drugs are likely to be additive… (Lidocaine and prilocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

…combination with others drugs or herbal products that are known to prolong the QT interval, including Class 1A (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmics, antipsychotics (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), or any other drug known to prolong the QT interval… (Loperamide label, Warnings)

Examples: Drugs known to have potential to prolong QT interval: Class I and III antiarrhythmics, some neuroleptics and tricyclic antidepressants, and calcium channel blockers. (Methadone label, Drug interactions)

WARNINGS XYLOCAINE INJECTIONS FOR INFILTRATION AND NERVE BLOCK SHOULD BE EMPLOYED ONLY BY CLINICIANS WHO ARE WELL VERSED IN DIAGNOSIS AND MANAGEMENT OF DOSE-RELATED TOXICITY AND OTHER ACUTE EMERGENCIES THAT MIGHT ARISE FROM THE BLOCK TO BE EMPLOYED AND THEN ONLY AFTER ENSURING THE IMMEDIATE AVAILABILITY OF OXYGEN, OTHER RESUSCITATIVE DRUGS, CARDIOPULMONARY EQUIPMENT… (Lidocaine label, Warnings)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Ofloxacin should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalemia, and patients receiving Class IA (quinidine, procainamide), or Class III (amiodarone, sotalol) antiarrhythmic agents. (Ofloxacin label, Precautions)

…paliperidone should be avoided in combination with other drugs that are known to prolong QTc including Class 1A (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications, antipsychotic medications (e.g., chlorpromazine, thioridazine), antibiotics (e.g., gatifloxacin, moxifloxacin), or any other class of medications known to… (Paliperidone label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

The use of NUPLAZID should be avoided in patients with known QT prolongation or in combination with other drugs known to prolong QT interval including Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class 3 antiarrhythmics (e.g., amiodarone, sotalol), certain antipsychotic medications (e.g., ziprasidone, chlorpromazine, thioridazine), and certain… (Pimavanserin label, Warnings and precautions)

It should be used with caution in persons with seizure disorders or in persons who are using concomitant medications, such as narcotics or local anesthetics, which may also affect seizure threshold. (Promethazine label, Warnings)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Other Highly Protein-Bound Drugs EVISTA should be used with caution with certain other highly protein-bound drugs such as diazepam, diazoxide, and lidocaine. (Raloxifene label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

…non-hormonal methods of birth control during rifampin therapy Estrogens Decrease exposure Progestins Anticonvulsants Phenytoin Administered with rifampin 450 mg daily Decrease exposure Antiarrhythmics Disopyramide Decrease exposure Mexiletine Decrease exposure Quinidine Decrease exposure Propafenone Decrease AUC by 50%–67% Tocainide Decrease exposure Antiestrogens… (Rifampin label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Extravasation: Prompt elevation of the area, warmth, and local injection of lidocaine or hyaluronidase are recommended to reduce the likelihood of tissue sloughing at the site. (Sodium bicarbonate label, Warnings and precautions)

Antiarrhythmics: amiodarone Effect on amiodarone, sofosbuvir, velpatasvir, and voxilaprevir concentrations unknown Coadministration of amiodarone with VOSEVI may result in serious symptomatic bradycardia. (Sofosbuvir and velpatasvir label, Drug interactions)

Antiarrhythmic and other QT Prolonging Drugs Withdraw other Class I or Class III antiarrhythmic agents prior to dosing with sotalol. (Sotalol label, Drug interactions)

…electrocardiograms and monitoring electrolytes (magnesium, potassium, calcium) periodically during treatment in patients with congestive heart failure, bradyarrhythmias, those taking certain antiarrhythmic medications or other products that lead to QT prolongation, and those with electrolyte disturbances (e.g., hypokalemia, hypocalcemia, or hypomagnesemia). (Tacrolimus label, Warnings and precautions)

…are known to prolong QTc, including antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications known to prolong the QTc interval [see Drug Interactions ( 7.5 )]. (Tetrabenazine label, Warnings and precautions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Concurrent administration of vasopressor drugs (for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

Clinically Significant Drug Interactions The administration of local anesthetic solutions containing epinephrine or norepinephrine to patients receiving monoamine oxidase inhibitors or tricyclic antidepressants may produce severe, prolonged hypertension. (Lidocaine label, Drug interactions)

BISOPROLOL FUMARATE should be used with care when myocardial depressants or inhibitors of AV conduction, such as certain calcium antagonists (particularly of the phenylalkylamine [verapamil] and benzothiazepine [diltiazem] classes), or antiarrhythmic agents, such as disopyramide, are used concurrently. (Bisoprolol label, Drug interactions)

Application-Associated Pain Even following use of a local anesthetic prior to administration of QUTENZA, patients may experience substantial procedural pain and burning upon application of QUTENZA and following removal of QUTENZA. (Capsaicin label, Warnings and precautions)

These include Class 1A (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmics, certain antipsychotics (e.g., ziprasidone, iloperidone, clozapine, quetiapine, chlorpromazine), certain antidepressants (e.g., citalopram, fluoxetine), certain antibiotics (e.g., azithromycin, erythromycin, clarithromycin, gatifloxacin, moxifloxacin);… (Hydroxyzine label, Precautions)

Cardiac Rhythm and Conduction Abnormalities In vitro testing showed that lamotrigine exhibits Class IB antiarrhythmic activity at therapeutically relevant concentrations [see Clinical Pharmacology ( 12.2 )] . (Lamotrigine label, Warnings and precautions)

Calcium Channel Blockers BYSTOLIC can exacerbate the effects of myocardial depressants or inhibitors of AV conduction, such as certain calcium antagonists (particularly of the phenylalkylamine [verapamil] and benzothiazepine [diltiazem] classes), or antiarrhythmic agents, such as disopyramide. (Nebivolol label, Drug interactions)

Interactions with general or local anesthetics have not been studied. (Ondansetron label, Drug interactions)

Pentoxifylline extended-release tablets have been used concurrently with antihypertensive drugs, beta blockers, digitalis, diuretics, and antiarrhythmics, without observed problems. (Pentoxifylline label, Drug interactions)

…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), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories–propoxyphene, aspirin, indomethacin, and phenylbutazone. (Prazosin label, Drug interactions)

Aminoglycoside antibiotics, local and some general anesthetics, antiarrhythmic agents, and other drugs that interfere with neuromuscular transmission should be used cautiously, if at all. (Pyridostigmine label, Drug interactions)

Drugs predominantly metabolized by the CYP450 2D6 isozyme include the following drug classes: tricyclic antidepressants, selective serotonin reuptake inhibitors, beta-blockers, antiarrhythmics class 1C (e.g., flecainide and propafenone) and monoamine oxidase inhibitors Type B. (Terbinafine label, Drug interactions)

Moderate or Weak CYP1A2 Inhibitors Concomitant use of Zanaflex with moderate or weak CYP1A2 inhibitors (e.g., zileuton, antiarrhythmics [amiodarone, mexiletine, propafenone, and verapamil], cimetidine, famotidine, oral contraceptives, acyclovir, and ticlopidine) should be avoided. (Tizanidine label, Drug interactions)

Drug Interactions No interactions have been observed between nizatidine and theophylline, chlordiazepoxide, lorazepam, lidocaine, phenytoin, and warfarin. (Nizatidine label, Drug interactions)