Propafenone Hydrochloride 325 mg Capsule, Extended Release, 500-count

5 WARNINGS AND PRECAUTIONS May cause new or worsened arrhythmias. Evaluate patients via ECG prior to and during therapy. (5.1) Propafenone HCl Extended Release may unmask Brugada or Brugada-like Syndrome.

Evaluate patients via ECG after initiation of therapy. (4, 5.2). Avoid use with other antiarrhythmic agents or drugs that prolong the QT interval.

(5.3) Avoid simultaneous use of propafenone with both a cytochrome P450 2D6 (CYP2D6) inhibitor and a 3A4 inhibitor (CYP3A4). (5.4) May provoke overt heart failure. (5.5) May cause dose-related first-degree AV block or other conduction disturbances.

Should not be given to patients with conduction defects in absence of a pacemaker. (5.6) May affect artificial pacemakers. Pacemakers should be monitored during therapy.

(5.7) Agranulocytosis: Patients should report signs of infection. (5.8) Administer cautiously to patients with impaired hepatic and renal function. (5.9, 5.10) Exacerbation of myasthenia gravis has been reported.

(5.11)

5.1Proarrhythmic Effects Propafenone has caused new or worsened arrhythmias. Such proarrhythmic effects include sudden death and life-threatening ventricular arrhythmias such as ventricular fibrillation, ventricular tachycardia, asystole, and torsade de pointes. It may also worsen premature ventricular contractions or supraventricular arrhythmias, and it may prolong the QT interval.

It is therefore essential that each patient given propafenone be evaluated electrocardiographically prior to and during therapy, to determine whether the response to propafenone ER capsules supports continued treatment. Because propafenone prolongs the QRS interval in the electrocardiogram, changes in the QT interval are difficult to interpret [see CLINICAL PHARMACOLOGY (12.2) ]. In the propafenone ER capsules Atrial Fibrillation Trial (RAFT) trial [see CLINICAL STUDIES (14) ], there were too few deaths to assess the long-term risk to patients.

There were 5 deaths, 3 in the pooled group for propafenone ER capsules (0.8%), and 2 in the placebo group (1.6%). In the overall database of 8 trials of propafenone ER capsules and immediate release propafenone, the mortality rate was 2.5% per year on propafenone and 4.0% per year on placebo. Concurrent use of propafenone with other antiarrhythmic agents has not been well studied.

In a U.S. uncontrolled, open-label, multicenter trial using the immediate release formulation in patients with symptomatic supraventricular tachycardia (SVT), 1.9% (9/474) of these patients experienced ventricular tachycardia (VT) or ventricular fibrillation (VF) during the trial. However, in 4 of the 9 patients, the ventricular tachycardia was of atrial origin. Six of the 9 patients that developed ventricular arrhythmias did so within 14 days of onset of therapy.

About 2.3% (11/474) of all patients had recurrence of SVT during the trial which could have been a change in the patients' arrhythmia behavior or could represent a proarrhythmic event. Case reports in patients treated with propafenone for atrial fibrillation/flutter have included increased premature ventricular contractions (PVCs), VT, VF, torsades de pointes, asystole, and death. Overall in clinical trials with propafenone immediate release (which included patients treated for ventricular arrhythmias, atrial fibrillation/flutter, and PSVT), 4.7% of all patients had new or worsened ventricular arrhythmia possibly representing a proarrhythmic event (0.7% was an increase in PVCs; 4.0% a worsening, or new appearance of VT or VF).

Of the patients who had worsening of VT (4%), 92% had a history of VT and/or VT/VF, 71% had coronary artery disease, and 68% had a prior myocardial infarction. The incidence of proarrhythmia in patients with less serious or benign arrhythmias, which include patients with an increase in frequency of PVCs, was 1.6%. Although most proarrhythmic events occurred during the first week of therapy, late events also were seen and the CAST trial [ see BOXED WARNING: MORTALITY ] suggests…

6 ADVERSE REACTIONS The most commonly reported adverse events with propafenone (greater than 5% and greater than placebo) excluding those not reasonably associated with the use of the drug included the following: dizziness, palpitations, chest pain, dyspnea, taste disturbance, nausea, fatigue, anxiety, constipation, upper respiratory tract infection, edema, and influenza. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Strides Pharma Inc 1-877-244-9825 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described below reflect exposure to propafenone ER capsules 225 mg twice daily in 126 patients, to propafenone ER capsules 325 mg twice daily in 135 patients, to propafenone ER capsules 425 mg twice daily in 136 patients, and to placebo in 126 patients for up to 39 weeks (mean: 20 weeks) in a placebo‑controlled trial (RAFT) conducted in the U.S.

The most commonly reported adverse events with propafenone (greater than 5% and greater than placebo) excluding those not reasonably associated with the use of the drug or because they were associated with the condition being treated, were dizziness, palpitations, chest pain, dyspnea, taste disturbance, nausea, fatigue, anxiety, constipation, upper respiratory tract infection, edema, and influenza. The frequency of discontinuation due to adverse events was 17%, and the rate was highest during the first 14 days of treatment.

Cardiac-related adverse events occurring in greater than or equal to 2% of the patients in any of the RAFT propafenone ER capsules treatment groups and more common with propafenone than with placebo, excluding those that are common in the population and those not plausibly related to drug therapy, included the following: angina pectoris, atrial flutter, AV block first-degree, bradycardia, congestive cardiac failure, cardiac murmur, edema, dyspnea, rales, wheezing, and cardioactive drug level above therapeutic. Propafenone prolongs the PR and QRS intervals in patients with atrial and ventricular arrhythmias.

Prolongation of the QRS interval makes it difficult to interpret the effect of propafenone on the QT interval [ see CLINICAL PHARMACOLOGY (12.2 )]. Non-cardiac related adverse events occurring in greater than or equal to 2% of the patients in any of the RAFT propafenone ER capsules treatment groups and more common with propafenone than with placebo, excluding those that are common in the population and those not plausibly related to drug therapy, included the following: blurred vision, constipation, diarrhea, dry mouth, flatulence, nausea, vomiting, fatigue, weakness, upper respiratory tract infection, blood alkaline phosphatase increased, hematuria, muscle weakness, dizziness (excluding vertigo), headache, taste disturbance, tremor, somnolence, anxiety, depression, ecchymosis.

No clinically important differences in incidence of adverse reactions were noted by age or gender. Too few non-Caucasian patients were enrolled to assess adverse events according to race. Adverse events occurring in 2% or more of the patients in any of the ERAFT [see CLINICAL STUDIES ( 14 )] propafenone ER capsules treatment groups and not listed above include the following: bundle branch block left, bundle branch block right, conduction disorders, sinus bradycardia, and hypotension.

Other adverse events reported with propafenone clinical trials not already listed elsewhere in the prescribing information include the following adverse events by body system and preferred term. Blood and Lymphatic System Anemia, lymphadenopathy, spleen disorder, thrombocytopenia. Cardiac Unstable angina, atrial hypertrophy, cardiac arrest, coronary artery disease, extrasystoles, myocardial infarction, noda…

7 DRUG INTERACTIONS Inhibitors of CYP2D6, 1A2, and 3A4 may increase propafenone levels which may lead to cardiac arrhythmias. Simultaneous use with both a CYP3A4 and CYP2D6 inhibitor (or in patients with CYP2D6 deficiency) should be avoided. (7.1) Propafenone may increase digoxin or warfarin levels.

(7.2, 7.3) Orlistat may reduce propafenone concentrations. Abrupt cessation of orlistat in patients stable on propafenone has resulted in convulsions, atrioventricular block, and circulatory failure. (7.4) Concomitant use of lidocaine may increase central nervous system side effects.

(7.6)

7.1CYP2D6 and CYP3A4 Inhibitors Drugs that inhibit CYP2D6 (such as desipramine, paroxetine, ritonavir, sertraline) and CYP3A4 (such as ketoconazole, ritonavir, saquinavir, erythromycin, grapefruit juice) can be expected to cause increased plasma levels of propafenone. The combination of CYP3A4 inhibition and either CYP2D6 deficiency or CYP2D6 inhibition with administration of propafenone may increase the risk of adverse reactions, including proarrhythmia. Therefore, simultaneous use of propafenone ER capsules with both a CYP2D6 inhibitor and a CYP3A4 inhibitor should be avoided [see WARNINGS and PRECAUTIONS (5.4), DOSAGE AND ADMINISTRATION (2)].

Amiodarone Concomitant administration of propafenone and amiodarone can affect conduction and repolarization and is not recommended. Cimetidine Concomitant administration of propafenone immediate release tablets and cimetidine in 12 healthy subjects resulted in a 20% increase in steady-state plasma concentrations of propafenone. Fluoxetine Concomitant administration of propafenone and fluoxetine in extensive metabolizers increased the S-propafenone C max and AUC by 39% and 50%, respectively, and the R-propafenone C max and AUC by 71% and 50%, respectively.

Quinidine Small doses of quinidine completely inhibit the CYP2D6 hydroxylation metabolic pathway, making all patients, in effect, slow metabolizers [ see CLINICAL PHARMACOLOGY ( 12 . 3 )]. Concomitant administration of quinidine (50 mg 3 times daily) with 150-mg immediate release propafenone 3 times daily decreased the clearance of propafenone by 60% in extensive metabolizers, making them poor metabolizers.

Steady-state plasma concentrations increased by more than 2-fold for propafenone and decreased 50% for 5-OH-propafenone. A 100-mg dose of quinidine increased steady-state concentrations of propafenone 3-fold. Avoid concomitant use of propafenone and quinidine.

Rifampin Concomitant administration of rifampin and propafenone in extensive metabolizers decreased the plasma concentrations of propafenone by 67% with a corresponding decrease of 5-OH-propafenone by 65%. The concentrations of norpropafenone increased by 30%. In poor metabolizers, there was a 50% decrease in propafenone plasma concentrations and an increase in the AUC and C max of norpropafenone by 74% and 20%, respectively.

Urinary excretion of propafenone and its metabolites decreased significantly. Similar results were noted in elderly patients: Both the AUC and C max of propafenone decreased by 84%, with a corresponding decrease in AUC and C max of 5-OH-propafenone by 69% and 57%, respectively.

7.2Digoxin Concomitant use of propafenone and digoxin increased steady-state serum digoxin exposure (AUC) in patients by 60% to 270% and decreased the clearance of digoxin by 31% to 67%. Monitor plasma digoxin levels of patients receiving propafenone and adjust digoxin dosage as needed.

7.3Warfarin The concomitant administration of propafenone and warfarin increased warfarin plasma concentrations at steady state by 39% in healthy volunteers and prolonged the prothrombin time (PT) in patients taking warfarin. Adjust the warfarin dose as needed by monitoring INR (international normalized ratio).

7.4Orlistat Orlistat may limit the fraction of propafenone available for absorption. In postmarketing reports, abrupt cessation of orlistat in patients stabilized on propafenone has resulted in severe adve…