Procainamide interactions

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)

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)

Drugs that Prolong QT Avoid use of AGRYLIN in patients taking medications that may prolong QT interval (including, but not limited to, chloroquine, clarithromycin, haloperidol, methadone, moxifloxacin, amiodarone, disopyramide, procainamide, and pimozide) [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.2) ] . (Anagrelide label, Drug interactions)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

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)

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)

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)

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)

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)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

…patients with asymptomatic non-life-threatening ventricular arrhythmias who had a myocardial infarction more than six days but less than two years previously, an excessive mortality or non-fatal cardiac arrest rate (7.7%) was seen in patients treated with encainide or flecainide compared with that seen in patients assigned to matched placebo-treated group (3.0%). (Procainamide label, Boxed warning)

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)

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)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

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)

Class Ia (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) anti-arrhythmic drugs have been associated with cases of Torsades de Pointes in patients with bradycardia. (Ponesimod label, Drug interactions)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

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)

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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

Idiosyncratic Hypersensitivity: In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity to PA is unlikely. (Procainamide label, Contraindications)

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)

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)

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)

…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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide label, Drug interactions)

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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Concurrent Other Antiarrhythmic Agents Concurrent use of PA with other Group 1A antiarrhythmic agents such as quinidine or disopyramide may produce enhanced prolongation of conduction or depression of contractility and hypotension, especially in patients with cardiac decompensation. (Procainamide label, Warnings)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Myasthenia Gravis Patients with myasthenia gravis may show worsening of symptoms from PA due to its procaine-like effect on diminishing acetylcholine release at skeletal muscle motor nerve endings, so that PA administration may be hazardous without optimal adjustment of anticholinesterase medications and other precautions. (Procainamide label, Warnings)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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)

Myasthenia Gravis Patients with myasthenia gravis may show worsening of symptoms from PA due to its procaine-like effect on diminishing acetylcholine release at skeletal muscle motor nerve endings, so that PA administration may be hazardous without optimal adjustment of anticholinesterase medications and other precautions. (Procainamide label, Warnings)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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)

Myasthenia Gravis Patients with myasthenia gravis may show worsening of symptoms from PA due to its procaine-like effect on diminishing acetylcholine release at skeletal muscle motor nerve endings, so that PA administration may be hazardous without optimal adjustment of anticholinesterase medications and other precautions. (Procainamide 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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Myasthenia Gravis Patients with myasthenia gravis may show worsening of symptoms from PA due to its procaine-like effect on diminishing acetylcholine release at skeletal muscle motor nerve endings, so that PA administration may be hazardous without optimal adjustment of anticholinesterase medications and other precautions. (Procainamide label, Warnings)

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

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Therefore, use of procainamide should be considered only if discontinuation of digitalis, and therapy with potassium, lidocaine, or phenytoin are ineffective. (Procainamide label, Warnings)

Myasthenia Gravis Patients with myasthenia gravis may show worsening of symptoms from PA due to its procaine-like effect on diminishing acetylcholine release at skeletal muscle motor nerve endings, so that PA administration may be hazardous without optimal adjustment of anticholinesterase medications and other precautions. (Procainamide label, Warnings)

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)

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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Myasthenia Gravis Patients with myasthenia gravis may show worsening of symptoms from PA due to its procaine-like effect on diminishing acetylcholine release at skeletal muscle motor nerve endings, so that PA administration may be hazardous without optimal adjustment of anticholinesterase medications and other precautions. (Procainamide label, Warnings)

…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)

High doses of ranitidine (e.g., such as those used in the treatment of Zollinger-Ellison syndrome) have been shown to reduce the renal excretion of procainamide and N-acetylprocainamide resulting in increased plasma levels of these drugs. (Ranitidine 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)

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)

Myasthenia Gravis Patients with myasthenia gravis may show worsening of symptoms from PA due to its procaine-like effect on diminishing acetylcholine release at skeletal muscle motor nerve endings, so that PA administration may be hazardous without optimal adjustment of anticholinesterase medications and other precautions. (Procainamide label, Warnings)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide 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)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide 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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

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

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine. (Procainamide label, Drug interactions)

Patients taking PA who require neuromuscular blocking agents such as succinylcholine may require less than usual doses of the latter, due to PA effects on reducing acetylcholine release. (Procainamide label, Drug interactions)

Although not studied with alosetron, inhibition of N-acetyltransferase may have clinically relevant consequences for drugs such as isoniazid, procainamide, and hydralazine. (Alosetron 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)

About half of the reported cases had serum creatinine ≥ 1.6 mg/dL and more than 75 percent were in patients also receiving procainamide. (Captopril 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)

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)

…for Drug Interaction: It appears possible, although there is no supporting experimental evidence, that the high renal clearance of desglymidodrine (a base) is due to active tubular secretion by the base-secreting system also responsible for the secretion of such drugs as metformin, cimetidine, ranitidine, procainamide, triamterene, flecainide, and quinidine. (Midodrine label, 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)

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

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)