Ibutilide 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)

Drug Class Drugs within class that are contraindicated with REYATAZ Alpha 1-adrenoreceptor antagonist Alfuzosin Anticonvulsants Carbamazepine, phenobarbital, phenytoin Antiarrhythmics Amiodarone (with ritonavir), quinidine (with ritonavir) Antimycobacterials Rifampin Antineoplastics Apalutamide, encorafenib, irinotecan, ivosidenib Antipsychotics Lurasidone (with… (Atazanavir label, Contraindications)

This risk which can be fatal should be considered in patients with certain cardiovascular disorders including known QT prolongation or history torsades de pointes, those with proarrhythmic conditions, and with other drugs that prolong the QT interval. (Azithromycin label, Warnings and precautions)

Avoid use in patients with known prolongation, those with hypokalemia, and with other drugs that prolong the QT interval. (Ciprofloxacin 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)

Considering the known proarrhythmic properties of Norpace or Norpace CR and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of Norpace or Norpace CR as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmias. (Disopyramide label, Boxed warning)

Use with Drugs that Prolong QT Interval and Antiarrhythmic Agents The use of dofetilide in conjunction with other drugs that prolong the QT interval has not been studied and is not recommended. (Dofetilide label, Warnings)

Concomitant use of COMPLERA with drugs with a known risk to prolong the QTc interval of the electrocardiogram may increase the risk of Torsade de Pointes. (Emtricitabine, rilpivirine, and tenofovir label, Warnings and precautions)

Coadministration of other drugs known to prolong the QT interval and which are metabolized via the enzyme CYP3A4 such as erythromycin, pimozide, and quinidine are contraindicated in patients receiving fluconazole. (Fluconazole label, Contraindications)

Fosamprenavir calcium is contraindicated when coadministered with the following drugs: Alpha 1-adrenoreceptor antagonist: Alfuzosin Antiarrhythmics: Flecainide (with ritonavir ), propafenone (with ritonavir ) Antimycobacterial: Rifampin Antipsychotic: Lurasidone (with ritonavir ), pimozide Ergot derivatives: Dihydroergotamine, ergonovine, ergotamine, methylergonovine… (Fosamprenavir label, Contraindications)

(See DOSAGE and ADMINISTRATION. ) Because of the risk of QT prolongation and the potential for torsades de pointes, the use of FOSCAVIR should be avoided in combination with agents known to prolong the QT interval including Class IA (e.g., quinidine or procainamide) or Class III (e.g., dofetilide, amiodarone, sotalol) antiarrhythmic agents, phenothiazines, tricyclic… (Foscarnet label, Drug interactions)

Avoid co-administration of CONTEPO with drugs known to prolong the QT interval. (Fosfomycin label, Drug interactions)

Therefore, PLAQUENIL is not recommended in patients taking other drugs that have the potential to prolong the QT interval. (Hydroxychloroquine label, Warnings and precautions)

Avoid the use of FANAPT in combination with any other drugs that prolong the QT interval [see Warnings and Precautions (5.3) ] . (Iloperidone label, Drug interactions)

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

Bradycardia may increase the risk of QT prolongation which may lead to severe ventricular arrhythmias, including torsade de pointes, especially in patients with risk factors such as use of QTc prolonging drugs [see Adverse Reactions ( 6.2 )] . (Ivabradine label, Warnings and precautions)

These conditions include patients with hypokalemia or hypomagnesemia, with congenital long QT syndrome, patients taking antiarrhythmic medicines or other medicinal products with known risk for QT prolongation/ Torsades de Pointes, and cumulative high-dose anthracycline therapy. (Lapatinib label, Warnings and precautions)

Avoid use in patients with known prolongation, those with hypokalemia, and with other drugs that prolong the QT interval ( 5.11 , 8.5 ) (Levofloxacin label, Warnings and precautions)

Alpha 1- Adrenoreceptor Antagonist: alfuzosin Antianginal: ranolazine Antiarrhythmic: dronedarone Anti-gout: colchicine Antipsychotics: lurasidone, pimozide Ergot Derivatives: dihydroergotamine, ergotamine, methylergonovine GI Motility Agent: cisapride Hepatitis C direct acting antiviral: elbasvir/grazoprevir HMG-CoA Reductase Inhibitors: lovastatin, simvastatin… (Lopinavir and ritonavir label, Contraindications)

Considering the known proarrhythmic properties of mexiletine and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of mexiletine as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmia. (Mexiletine label, Boxed warning)

Examples diazepam, alprazolam, alcohol Drugs that Prolong QTc Interval Clinical Impact The concomitant use of other drugs which prolong the QTc interval with REMERON/REMERONSolTab, increase the risk of QT prolongation and/or ventricular arrhythmias (e.g., Torsades de Pointes). (Mirtazapine label, Drug interactions)

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)

Avoid coadministration of oxaliplatin injection with medicinal products with a known potential to prolong the QT interval. (Oxaliplatin label, Drug interactions)

Avoid coadministration of VOTRIENT with drugs known to prolong the QT/QTc interval. (Pazopanib label, Drug interactions)

Drugs that Prolong the QT Interval : Avoid concomitant use. (Phenobarbital label, Drug interactions)

Because pimozide prolongs the QT interval of the electrocardiogram it is contraindicated in patients with congenital long QT syndrome, patients with a history of cardiac arrhythmias, patients taking other drugs which prolong the QT interval of the electrocardiogram or patients with known hypokalemia or hypomagnesemia (see also PRECAUTIONS - DRUG INTERACTIONS ). (Pimozide label, Contraindications)

The use of WAKIX should be avoided in patients with known QT prolongation or in combination with other drugs known to prolong the QT interval [see Drug Interactions ( 7.1 )]. (Pitolisant label, Warnings and precautions)

Considering the known proarrhythmic properties of procainamide and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of procainamide as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmias. (Procainamide label, Boxed warning)

• 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)

Proarrhythmic effects Like many other drugs (including all other Class Ia antiarrhythmics), quinidine prolongs the QT c interval, and this can lead to torsades de pointes , a life-threatening ventricular arrhythmia (see OVERDOSAGE ). (Quinidine label, Warnings)

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)

Avoid the concomitant use of drugs known to prolong the QTc interval. (Sertraline label, Drug interactions)

Certain conditions may increase the risk for torsade de pointes or sudden death such as (1) bradycardia; (2) hypokalemia or hypomagnesemia; (3) concomitant use of other drugs that prolong the QTc interval; and (4) presence of congenital prolongation of the QT interval [see Warnings and Precautions ( 5.8 ), Clinical Pharmacology (12.2) ]. (Tetrabenazine label, Drug interactions)

CONTRAINDICATIONS Thioridazine hydrochloride tablet use should be avoided in combination with other drugs that are known to prolong the QTc interval and in patients with congenital long QT syndrome or a history of cardiac arrhythmias. (Thioridazine label, Contraindications)

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)

Avoid concomitant use of VEPPANU with strong CYP3A inhibitors or drugs known to prolong the QTc interval. (Vepdegestrant label, Warnings and precautions)

…drugs, ziprasidone is contraindicated: • in patients with a known history of QT prolongation (including congenital long QT syndrome) • in patients with recent acute myocardial infarction • in patients with uncompensated heart failure Pharmacokinetic/pharmacodynamic studies between ziprasidone and other drugs that prolong the QT interval have not been performed. (Ziprasidone label, Contraindications)

MAO inhibitors, tricyclic antidepressants and drugs that prolong the QTc interval may potentiate effect on the cardiovascular system. (Arformoterol 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)

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

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

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)

Drugs that Prolong the QT interval QT prolongation has been reported with metronidazole, a component of bismuth subcitrate potassium, metronidazole and tetracycline hydrochloride, particularly when administered with drugs with the potential for prolonging the QT interval. (Bismuth subcitrate, metronidazole, and tetracycline label, Warnings and precautions)

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)

The risk of combining buprenorphine with other QT-prolonging agents is not known. (Buprenorphine label, Warnings and precautions)

The risk of combining buprenorphine with other QT-prolonging agents is not known. (Buprenorphine and naloxone label, Warnings and precautions)

Drugs Metabolized by CYP2D6: Bupropion inhibits CYP2D6 and can increase concentrations of: antidepressants (e.g., venlafaxine, nortriptyline, imipramine, desipramine, paroxetine, fluoxetine, sertraline), antipsychotics (e.g., haloperidol, risperidone, thioridazine), beta-blockers (e.g., metoprolol), and Type 1C antiarrhythmics (e.g., propafenone, flecainide). (Bupropion label, Drug interactions)

QT Interval Prolongation and V entricular A rr h ythmia Decreases in serum calcium can also prolong the QT interval, potentially resulting in ventricular arrhythmia. (Cinacalcet label, Warnings and precautions)

Avoid use of Citalopram Capsules in patients with congenital long QT syndrome, bradycardia, hypokalemia or hypomagnesemia, recent acute myocardial infarction, or uncompensated heart failure and patients taking other drugs that prolong the QTc interval. (Citalopram label, Warnings and precautions)

…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)

Other antiarrhythmics e.g. amiodarone, bepridil, disopyramide, flecainide, lidocaine (systemic), mexiletine, propafenone, quinidine ↑ antiarrhythmics Therapeutic concentration monitoring, if available, is recommended for antiarrhythmics when co-administered with PREZISTA/ritonavir. digoxin ↑ digoxin The lowest dose of digoxin should initially be prescribed. (Darunavir label, Drug interactions)

Other antiarrhythmics e.g. amiodarone, disopyramide, flecainide, lidocaine (systemic), mexiletine, propafenone, quinidine ↑ antiarrhythmics Clinical monitoring is recommended upon co-administration with antiarrhythmics. digoxin ↑ digoxin When co-administering with digoxin, titrate the digoxin dose and monitor digoxin concentrations. (Darunavir and cobicistat label, Drug interactions)

QT Prolongation PHYRAGO may increase the risk of prolongation of QTc in patients including those with hypokalemia or hypomagnesemia, patients with congenital long QT syndrome, patients taking antiarrhythmic medicines or other medicinal products that lead to QT prolongation, and cumulative high-dose anthracycline therapy [see Adverse Reactions ( 6.1 )] . (Dasatinib label, Warnings and precautions)

Carefully monitor cardiac rhythm when administering SUPRANE to susceptible patients (e.g., patients with congenital Long QT Syndrome or patients taking drugs that can prolong the QT interval). (Desflurane label, Warnings and precautions)

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)

Digoxin: Supraventricular arrhythmias may mask the cardiotoxicity associated with excessive digoxin levels. (Ibutilide label, Drug interactions)

…development of prolonged QT syndrome, such as: 1) clinically significant bradycardia (less than 50 bpm), 2) any clinically significant cardiac disease, 3) treatment with Class I 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 (see PRECAUTIONS,… (Droperidol label, Warnings)

QT Prolonging Drugs There is limited information available on the potential for a pharmacodynamic interaction between efavirenz and drugs that prolong the QTc interval. (Efavirenz label, Drug interactions)

QT Prolonging Drugs There is limited information available on the potential for a pharmacodynamic interaction between EFV and drugs that prolong the QTc interval. (Efavirenz, lamivudine, and tenofovir label, Drug interactions)

Antiarrhythmics: e.g., amiodarone bepridil digoxin Indicates that a drug-drug interaction trial was conducted. disopyramide flecainide systemic lidocaine mexiletine propafenone quinidine ↑ antiarrhythmics ↑ digoxin Caution is warranted and therapeutic concentration monitoring, if available, is recommended for antiarrhythmics when coadministered with GENVOYA. (Elvitegravir, cobicistat, emtricitabine, and tenofovir label, Drug interactions)

QT Prolongation: Monitor for prolonged QT intervals in patients with congestive heart failure, bradyarrhythmias, drugs known to prolong the QT interval, and electrolyte abnormalities. (Eribulin label, Warnings and precautions)

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)

Other agents Antiarrhythmics : digoxin ↔ etravirine ↑ digoxin For patients who are initiating a combination of Etravirine and digoxin, the lowest dose of digoxin should initially be prescribed. (Etravirine 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)

Use with caution in combination with other drugs that prolong the QT interval ( 4.2 , 5.11 , 7.7 , 7.8 ) 7.1 Monoamine Oxidase Inhibitors (MAOI) [See Dosage and Administration ( 2.9 , 2.10 ), Contraindications ( 4.1 ), and Warnings and Precautions ( 5.2 )] . (Fluoxetine label, Drug interactions)

…Antidepressants, QTc Prolonging Drugs Formoterol, as with other beta 2 -agonists, should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors, tricyclic antidepressants, or drugs known to prolong the QTc interval because the effect of adrenergic agonists on the cardiovascular system may be potentiated by these agents. (Formoterol 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)

Effect on QT/QTc Interval: Androgen deprivation therapy may prolong the QT interval. (Goserelin label, Warnings and precautions)

This observation should be considered in making clinical decisions regarding patient monitoring when prescribing HYSINGLA ER in patients with congestive heart failure, bradyarrhythmias, electrolyte abnormalities, or who are taking medications that are known to prolong the QTc interval. (Hydrocodone label, Warnings and precautions)

Monitor QT interval when administering FORANE to susceptible patients (e.g., patients with congenital Long QT Syndrome or patients taking drugs that can prolong the QT interval). (Isoflurane label, Warnings and precautions)

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)

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

Clinical Comment Antiarrhythmics: digoxin ↑ digoxin Use with caution and monitor digoxin therapeutic concentration. (Lenacapavir label, Drug interactions)

Effect on QT/QTc Interval: Androgen deprivation therapy may prolong the QT interval. (Leuprolide label, Warnings and precautions)

Risk of QT Prolongation : Lofexidine tablets prolong the QT interval. (Lofexidine label, Warnings and precautions)

…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)

Other Drugs that Prolong the QTc Interval Coadministration of other drugs known to alter cardiac conduction (e.g., anti-arrhythmic or beta-adrenergic blocking agents, calcium channel blockers, antihistamines or H 1 -blocking agents, tricyclic antidepressants and phenothiazines) might also contribute to a prolongation of the QTc interval. (Mefloquine label, Drug interactions)

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)

Drugs that Prolong the QT Interval QT prolongation has been reported, particularly when metronidazole was administered with drugs with the potential for prolonging the QT interval. (Metronidazole label, Drug interactions)

There is little or no experience with high exposure, concomitant dosing with other QT-prolonging drugs, or potassium channel variants resulting in a long QT interval. [See Warnings & Precautions ( 5.6 )] To minimize risk, the lowest effective dose should always be used. (Mifepristone label, Warnings and precautions)

Drugs Metabolized by CYP2D6: Bupropion inhibits CYP2D6 and can increase concentrations of antidepressants, (e.g., selective serotonin reuptake inhibitors and many tricyclics), antipsychotics (e.g., haloperidol, risperidone and thioridazine), beta-blockers (e.g., metoprolol) and Type 1C antiarrhythmics (e.g., propafenone and flecainide). (Naltrexone and bupropion label, Drug interactions)

Antiarrhythmics: Amiodarone, disopyramide, lidocaine Plasma concentrations may be decreased. (Nevirapine 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)

Use olanzapine and fluoxetine capsules with caution in combination with other drugs that prolong the QT interval ( 4.2 , 5.20 , 7.7 , 7.8 ) 7.1 Monoamine Oxidase Inhibitors (MAOIs) [See Dosage and Administration ( 2.4 , 2.5 ), Contraindications ( 4.1 ), and Warnings and Precautions ( 5.6 )] . (Olanzapine and fluoxetine label, Drug interactions)

…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 prolong the QTc interval. (Paliperidone label, Warnings and precautions)

Drugs that Prolong QT: Use with caution in patients who are at significant risk of developing QTc prolongation. (Pasireotide 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)

Anti-Arrhythmic Drugs, QT Prolonging Drugs, Drugs that may Decrease Heart Rate PONVORY has not been studied in patients taking QT prolonging drugs. (Ponesimod label, Drug interactions)

QT Interval Prolonging Drugs The pharmacodynamic interaction potential to prolong the QT interval of the electrocardiogram between Primaquine phosphate Tablets and other drugs that effect cardiac conduction is unknown. (Primaquine label, Drug interactions)

…Class 1A antiarrythmics (e.g., quinidine, procainamide) or Class III antiarrythmics (e.g., amiodarone, sotalol), antipsychotic medications (e.g., ziprasidone, chlorpromazine, thioridazine), antibiotics (e.g., gatifloxacin, moxifloxacin), or any other class of medications known to prolong the QTc interval (e.g., pentamidine, levomethadyl acetate, methadone). (Quetiapine label, Warnings and precautions)

Quinine sulfate is not recommended for use with other drugs known to cause QT prolongation, including Class IA antiarrhythmic agents (e.g., quinidine, procainamide, disopyramide), and Class III antiarrhythmic agents (e.g., amiodarone, sotalol, dofetilide). (Quinine label, Warnings and precautions)

…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)

Table 4: Drug Interactions with PRIFTIN: Dosage Adjustment May be Necessary Drug Class Examples of Drugs Within Class Antiarrhythmics Disopyramide, mexiletine, quinidine, tocainide Antibiotics Chloramphenicol, clarithromycin, dapsone, doxycycline; Fluoroquinolones (such as ciprofloxacin) Oral Anticoagulants Warfarin Anticonvulsants Phenytoin Antimalarials Quinine… (Rifapentine label, Drug interactions)

In healthy subjects, 75 mg once daily and 300 mg once daily (3 times and 12 times the dose in EDURANT) have been shown to prolong the QTc interval of the electrocardiogram. (Rilpivirine label, Warnings and precautions)

QT Interval Prolongation The overall analysis of ECG data in pediatric patients indicates that the concomitant use of Rocuronium Bromide Injection with general anesthetic agents can prolong the QTc interval [see Clinical Studies ( 14.3 )]. (Rocuronium label, Warnings and precautions)

…anesthetics or agents structurally related to amide- type local anesthetics, since the toxic effects of these drugs are additive. [See Drug Interactions 7.0 ] Patients treated with class III antiarrhythmic drugs (e.g., amiodarone) should be under close surveillance and ECG monitoring considered, since cardiac effects may be additive. [See Drug Interactions 7.0… (Ropivacaine label, Warnings and precautions)

Caution should be exercised when administering sevoflurane to susceptible patients (e.g., patients with congenital Long QT Syndrome or patients taking drugs that can prolong the QT interval). (Sevoflurane label, Warnings)

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)

Monitor electrolytes and electrocardiograms in patients with congestive heart failure, bradyarrhythmias, drugs known to prolong the QT interval, including Class Ia and III antiarrhythmics. (Sorafenib label, Warnings and precautions)

Additive to other QT-prolonging drugs ( 7.1 , 7.2 ) (Sotalol label, Drug interactions)

Monitor patients who are at higher risk of developing QT interval prolongation, including patients with a history of QT interval prolongation, patients who are taking antiarrhythmics, or patients with relevant pre-existing cardiac disease, bradycardia, or electrolyte disturbances. (Sunitinib label, Warnings and precautions)

…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)

Agents generally accepted to prolong QT interval include Class 1A (e.g., quinidine, procainamide, disopyramide) and Class III (e.g., amiodarone, sotalol, ibutilide, dofetilide) antiarrhythmics; certain antipsychotics (e.g., thioridazine, haloperidol); certain antidepressants (e.g., venlafaxine, amitriptyline); certain antibiotics (e.g., erythromycin, clarithromycin,… (Toremifene label, Drug interactions)

…prolongation or in combination with other drugs that are inhibitors of CYP3A4 (e.g., itraconazole, clarithromycin, voriconazole), or 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),… (Trazodone label, Warnings and precautions)

Effect on QT/QTc Interval: Androgen deprivation therapy may prolong the QT interval. (Triptorelin label, Warnings and precautions)

…like other beta 2 -agonists, should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors, tricyclic antidepressants, or drugs known to prolong the QTc interval or within 2 weeks of discontinuation of such agents, because the effect of adrenergic agonists on the cardiovascular system may be potentiated by these agents. (Umeclidinium and vilanterol label, Drug interactions)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide). (Amitriptyline label, Drug interactions)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine, cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide). (Amoxapine 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)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide). (Clomipramine label, Drug interactions)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type IC antiarrhythmics propafenone and flecainide). (Desipramine label, Drug interactions)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

Examples include (but are not limited to): Class 1A antiarrhythmics (e.g., procainamide, quinidine, disopyramide); Class 3 antiarrhythmics (e.g., amiodarone, sotalol); and other drugs such as citalopram, erythromycin, levofloxacin, methadone, and ziprasidone. (Haloperidol label, Drug interactions)

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)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide). (Imipramine label, Drug interactions)

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)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

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)

Cardiovascular Drugs Antiarrhythmics Quinidine: Quinidine is a substrate of CYP3A and has been shown to inhibit CYP3A in vitro . (Nifedipine label, Drug interactions)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide). (Nortriptyline 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)

Drug Interactions Metabolism of a number of medications, including antipsychotics, antidepressants, β-blockers, and antiarrhythmics, occurs through the cytochrome P450 2D6 isoenzyme (debrisoquine hydroxylase). (Perphenazine 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)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics, propafenone and flecainide). (Protriptyline label, Precautions)

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)

The drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide). (Trimipramine label, Drug interactions)

WARNINGS Proarrhythmia: Like other antiarrhythmic agents, CORVERT Injection can induce or worsen ventricular arrhythmias in some patients. (Ibutilide label, Warnings)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Calcium channel blocking agents: Coadministration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)

Beta-adrenergic blocking agents: Coadministration of beta-adrenergic blocking agents did not have any effect on either the safety or efficacy of ibutilide in the clinical trials. (Ibutilide label, Drug interactions)