Propafenone available by the brand name of Rythmol is a class 1C antiarrhythmic drug that has membrane-stabilizing and anesthetic properties.
Indications of propafenone:
- It is indicated for the treatment of life-threatening ventricular arrhythmias, to prolong the time to recurrence of paroxysmal atrial fibrillation/ flutter or paroxysmal supraventricular tachycardia in patients with disabling symptoms without structural heart disease
 - 
	
Extended-release capsule:
- It is useful for prolonging the time to recurrence of symptomatic atrial fibrillation in patients without structural heart disease.
 
 - 
	
Off Label Use of Propafenone in Adults:
- Paroxysmal atrial fibrillation (pharmacological cardioversion);
 - Ventricular premature beats
 
 
Propafenone dose in adults:
Note:
Dose reduction is required for patients with a significant widening of QRS complex or second- or third-degree AV block.
Propafenone dose in the treatment of Atrial fibrillation to prevent recurrence:
- 
	
Extended-release capsule:
- Initial: 225 mg per oral every 12 hours;
 - The dosage increase may be made at a minimum of 5-day intervals;
 - The dose may be increased to 325 mg every 12 hours;
 - if a further increase is necessary, the dose may be increased to 425 mg every 12 hours.
 
 - 
	
Immediate-release tablet:
- Initial: 150 mg per oral every 8 hours;
 - Dosage increase may be made at a minimum of 3- to 4-day intervals, may increase to 225 mg every 8 hours;
 - If a further increase is necessary, may increase to 300 mg every 8 hours.
 
 
Propafenone dose in the treatment of Paroxysmal supraventricular tachycardia to prevent recurrence:
- 
	
Immediate-release tablet:
- Initial: 150 mg per oral every 8 hours;
 - The dosage may be increased at a minimum of 3- to 4-day intervals to 225 mg every 8 hours;
 - If a further increase is necessary, may increase to 300 mg every 8 hours.
 
 - 
	
Alternate recommendations:
- 
		
Immediate-release tablet:
- Initial: 150 mg per oral every 8 hours;
 - The maximum maintenance dose: 300 mg every 8 hours.
 
 - 
		
Extended-release capsule:
- Initial: 225 mg per oral every 12 hours
 - maximum maintenance dose: 425 mg every 12 hours.
 
 
 - 
		
 
Propafenone (Rythmol) dose for the pharmacologic cardioversion of Paroxysmal atrial fibrillation:
Note:
- May be used on an outpatient basis (“Pill-in-the-pocket”).
 - The patient must be taking an AV nodal-blocking agent (eg, Beta-blocker, non-dihydropyridine calcium channel blocker) before starting antiarrhythmic.
 - 
	
Immediate-release tablet:
- weight <70 kg:
		
- 450 mg
 
 - weight ≥70 kg:
		
- 600 mg
 
 - May not repeat in ≤24 hours
 
 - weight <70 kg:
		
 
Propafenone (Rythmol) dose in the treatment of Ventricular arrhythmia:
- 
	
Immediate-release tablet:
- 150 mg per oral every 8 hours; dosage increase may be made at a minimum of 3- to 4-day intervals, may increase to 225 mg every 8 hours;
 - If a further increase is necessary, may increase to 300 mg every 8 hours.
 
 - 
	
Extended-release capsule (off- label dose):
- 225 to 425 mg per oral every 12 hours.
 
 
Propafenone (Rythmol) dose in the treatment of Ventricular premature beats:
- 
	
Immediate-release tablet:
- 150 to 300 mg per oral every 8 hours
 
 - 
	
Extended-release capsule:
- 225 to 425 mg per oral every 12 hours
 
 
Dose in Children:
The safety and efficacy of the drug in children has not been established.
Pregnancy Risk Category: C
- The placenta is crossed by propafenone and 5-hydroxypropafenone, and they can be detected in the infant.
 - It should not be administered in any way and should be avoided during the first trimester.
 - For supraventricular tachycardia symptomatic, propafenone may be administered to pregnant women.
 - It is also helpful in preventing supraventricular tachycardia in patients with Wolff-Parkinson-White syndrome.
 - Propafenone should not be used as a first-line treatment. It is only recommended to treat arrhythmias in cases where other medications are not available.
 - It can lead to a reversible impairment in spermatogenesis for males.
 
Propafenone use during breastfeeding:
- Breast milk contains propafenone as well as the 5-hydroxypropafenone metabolism.
 - According to the case report, the relative infant dose (RID), of propafenone was 1% of weight-adjusted mother dose.
 - When the relative infant dose for a medication is less than 10%, breastfeeding is permitted.
 - Milk concentrations were 32 ng/mL (propafenone) and 47 ng/mL (5hydroxypropafenone).
 - Based on actual maternal weight, one author calculated that the RID was 0.03%. Another author estimated it to be 0.1%.
 - The milk was sipped at intervals of 1 to 12 hours following the last dose, regardless of postpartum age.
 - According to the manufacturer breastfeeding during therapy is a decision that should be made after considering the risks and benefits to the baby as well as the benefits to the mother.
 
Dose adjustment in renal disease:
50% of propafenone metabolites are excreted in the urine, however there are no dosage adjustments provided in the manufacturer's labeling
Hemodialysis/CVVH:
- Minimally dialyzable , supplemental dose not necessary
 
Dose adjustment in liver disease:
There are no dosage adjustment provided in the manufacturer’s labeling; however, dosage reduction is necesssary as drug undergoes hepatic metabolism. In patients with mild to moderate liver impairment, the following dosing recommendations have been made:
- Initial: 150 mg once daily; if necessary, the dose may be increased by 150 mg/day in divided doses (eg, b.i.d or t.i.d) at a minimum of 4-day intervals up to a maximum of 300 mg every 12 hours.
 
Common Side Effects of Propafenone:
- 
	
Central Nervous System:
- Unusual Taste
 - Dizziness
 
 - 
	
Gastrointestinal:
- Nausea
 - Vomiting
 
 
Side Effects Of Propafenone Include:
- 
	
Cardiovascular:
- Cardiac Arrhythmia
 - Angina Pectoris
 - Cardiac Failure
 - First Degree Atrioventricular Block
 - Palpitations
 - Ventricular Tachycardia
 - Bradycardia
 - Chest Pain
 - Widened QRS Complex On ECG
 - Syncope
 - Ventricular Premature Contractions
 - Atrial Fibrillation
 - Bundle Branch Block
 - Edema
 - Cardiac Conduction Delay
 - Hypotension
 
 - 
	
Central Nervous System:
- Fatigue
 - Headache
 - Ataxia
 - Insomnia
 - Anxiety
 - Drowsiness
 
 - 
	
Dermatologic:
- Skin Rash
 - Diaphoresis
 
 - 
	
Gastrointestinal:
- Constipation
 - Diarrhea
 - Dyspepsia
 - Abdominal Pain
 - Anorexia
 - Xerostomia
 - Flatulence
 
 - 
	
Neuromuscular & Skeletal:
- Weakness
 - Arthralgia
 - Tremor
 
 - 
	
Ophthalmic:
- Blurred Vision
 
 - 
	
Respiratory:
- Dyspnea
 
 
Contraindications to Propafenone:
- Hypersensitivity to propafenone and any component of the formulation
 - Cardiac failure
 - Cardiogenic shock
 - Bradycardia/ severe hypertension
 - COPD severe
 - Severe electrolyte imbalance
 - A, A.V, and intraventricular disorders in impulse generation or conduction.
 - Liver impairment severe
 - Myasthenia gravis
 - Concurrent use of ritonavir
 
Warnings and precautions
- 
	
Agranulocytosis
- Sometimes, granulocytosis may occur. It returns to normal within 2 weeks after therapy is stopped.
 
 - 
	
CNS effects
- Propafenone can cause blurred vision, dizziness, fatigue and dizziness. Patients should be cautious about driving or operating machinery.
 
 - 
	
Conduction disturbances:
- It can lead to prolonged PR, longer QRS duration, or slow atrioventricular Conduction, leading to first-degree AV block.
 
 - 
	
Titers of elevated antinuclear antibodies
- Positive antinuclear antibodies (ANA) were detected in some patients who received propafenone. However, not all of these cases resulted in drug-induced Lupus Erythematosus.
 - The decrease in titers is seen regardless of discontinuation of therapy. However, discontinuation is required for patients who are symptomatic and have positive ANA titers.
 
 - 
	
Hepatotoxicity:
- Hepatocellular injury, cholestasis and other causes of life-threatening liver abnormalities can lead to serious consequences.
 
 - 
	
Proarrhythmic effects
- Propafenone has been shown to prolong QT, ventricular fibrillation and asystole.
 - To prevent QT prolongation, monitoring and dose adjustment are essential.
 
 - 
	
Brugada syndrome:
- Brugada Syndrome may be unmaskable by Propafenone.
 - ECG should be performed after treatment initiation. Therapy should be stopped in Brugada Syndrome.
 
 - 
	
Electrolyte imbalance:
- Patients with electrolyte abnormalities not corrected are advised to avoid use.
 - It is important to correct electrolyte imbalances, especially hypokalemia and hypomagnesemia, before treatment.
 
 - 
	
Heart failure (HF):
- Propafenone can cause heart failure so it is best to avoid it.
 
 - 
	
Hepatic impairment
- Patients with hepatic impairment should be cautious.
 
 - 
	
Myasthenia gravis:
- Patients with myasthenia Gravis should be cautious. It may worsen the condition.
 
 - 
	
Pulmonary disease
- Patients with obstructive pulmonary disease can receive propafenone without bronchospasm.
 - However, severe obstructive pulmonary disease is where it is contraindicated.
 
 - 
	
Renal impairment
- Patients with impaired renal function should be cautious.
 
 
Propafenone: Drug Interaction
| 
			 Antihepaciviral Combination Products  | 
			
			 May increase the serum concentration of Propafenone. Management: Canadian labeling recommends avoiding this combination.  | 
		
| 
			 ARIPiprazole  | 
			
			 CYP2D6 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations.  | 
		
| 
			 Beta-Blockers  | 
			|
| 
			 Bradycardia-Causing Agents  | 
			
			 May enhance the bradycardic effect of other Bradycardia-Causing Agents.  | 
		
| 
			 Brentuximab Vedotin  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased.  | 
		
| 
			 Bretylium  | 
			
			 May enhance the bradycardic effect of Bradycardia-Causing Agents. Bretylium may also enhance atrioventricular (AV) blockade in patients receiving AV blocking agents.  | 
		
| 
			 Cardiac Glycosides  | 
			
			 Propafenone may increase the serum concentration of Cardiac Glycosides.  | 
		
| 
			 Celiprolol  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Celiprolol.  | 
		
| 
			 Cimetidine  | 
			
			 May increase the serum concentration of Propafenone.  | 
		
| 
			 CloBAZam  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 Cobicistat  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 CYP2D6 Inhibitors (Moderate)  | 
			
			 May decrease the metabolism of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 CYP2D6 Inhibitors (Moderate)  | 
			
			 May increase the serum concentration of Propafenone. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Exceptions: Thioridazine.  | 
		
| 
			 CYP3A4 Inducers (Strong)  | 
			
			 May decrease the serum concentration of Propafenone.  | 
		
| 
			 CYP3A4 Inhibitors (Moderate)  | 
			
			 May increase the serum concentration of Propafenone. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Exceptions: Crizotinib; Erythromycin (Systemic); Fluconazole; Nilotinib; Ribociclib.  | 
		
| 
			 CYP3A4 Inhibitors (Strong)  | 
			
			 May increase the serum concentration of Propafenone. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Exceptions: Clarithromycin; Saquinavir; Voriconazole.  | 
		
| 
			 Darunavir  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 Etravirine  | 
			
			 May decrease the serum concentration of Propafenone.  | 
		
| 
			 Everolimus  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Everolimus.  | 
		
| 
			 FLUoxetine  | 
			
			 Propafenone may enhance the QTc-prolonging effect of FLUoxetine. FLUoxetine may increase the serum concentration of Propafenone.  | 
		
| 
			 FluvoxaMINE  | 
			
			 May increase the serum concentration of Propafenone.  | 
		
| 
			 Haloperidol  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTcprolonging effect of Haloperidol. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 Imatinib  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 Ivabradine  | 
			
			 Bradycardia-Causing Agents may enhance the bradycardic effect of Ivabradine.  | 
		
| 
			 Lacosamide  | 
			
			 Bradycardia-Causing Agents may enhance the AV-blocking effect of Lacosamide.  | 
		
| 
			 Lacosamide  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the adverse/toxic effect of Lacosamide. Specifically the risk for bradycardia, ventricular tachyarrhythmias, or a prolonged PR interval may be increased.  | 
		
| 
			 Larotrectinib  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Larotrectinib.  | 
		
| 
			 Lumefantrine  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 Midodrine  | 
			
			 May enhance the bradycardic effect of Bradycardia-Causing Agents.  | 
		
| 
			 Mirabegron  | 
			
			 May increase the serum concentration of Propafenone. Management: Monitor clinical response to propafenone closely. Dose adjustment may be necessary. Canadian mirabegron labeling recommends restricting the maximum adult mirabegron dose to 25 mg/day in patients receiving propafenone.  | 
		
| 
			 Naldemedine  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Naldemedine.  | 
		
| 
			 Naloxegol  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Naloxegol.  | 
		
| 
			 Ondansetron  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTcprolonging effect of Ondansetron. Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 Orlistat  | 
			
			 May decrease the serum concentration of Propafenone.  | 
		
| 
			 Panobinostat  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 PARoxetine  | 
			
			 May increase the serum concentration of Propafenone.  | 
		
| 
			 Peginterferon Alfa-2b  | 
			
			 May decrease the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 Pentamidine (Systemic)  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTc-prolonging effect of Pentamidine (Systemic). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 Perhexiline  | 
			
			 CYP2D6 Inhibitors (Weak) may increase the serum concentration of Perhexiline.  | 
		
| 
			 Perhexiline  | 
			
			 CYP2D6 Substrates (High risk with Inhibitors) may increase the serum concentration of Perhexiline. Perhexiline may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 P-glycoprotein/ABCB1 Substrates  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of P-glycoprotein/ABCB1 Substrates. P-glycoprotein inhibitors may also enhance the distribution of p-glycoprotein substrates to specific cells/tissues/organs where p-glycoprotein is present in large amounts (e.g., brain, T-lymphocytes, testes, etc.). Exceptions: Loperamide.  | 
		
| 
			 Propranolol  | 
			
			 Propafenone may increase the serum concentration of Propranolol.  | 
		
| 
			 Prucalopride  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Prucalopride.  | 
		
| 
			 QT-prolonging Antidepressants (Moderate Risk)  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Antidepressants (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Antipsychotics (Moderate Risk)  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Antipsychotics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: Pimozide.  | 
		
| 
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk)  | 
			
			 May enhance the QTc-prolonging effect of other QT-prolonging Class IC Antiarrhythmics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Kinase Inhibitors (Moderate Risk)  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Kinase Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Miscellaneous Agents (Moderate Risk)  | 
			
			 May enhance the QTc-prolonging effect of QT-prolonging Class IC Antiarrhythmics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Exceptions: Domperidone.  | 
		
| 
			 QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk)  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Quinolone Antibiotics (Moderate Risk)  | 
			
			 May enhance the QTc-prolonging effect of QT-prolonging Class IC Antiarrhythmics (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk)  | 
			
			 QT-prolonging Class IC Antiarrhythmics (Moderate Risk) may enhance the QTc-prolonging effect of QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 Ranolazine  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Ranolazine.  | 
		
| 
			 RifAXIMin  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of RifAXIMin.  | 
		
| 
			 Ruxolitinib  | 
			
			 May enhance the bradycardic effect of Bradycardia-Causing Agents. Management: Ruxolitinib Canadian product labeling recommends avoiding use with bradycardia-causing agents to the extent possible.  | 
		
| 
			 Sertraline  | 
			
			 May enhance the QTc-prolonging effect of Propafenone. Sertraline may increase the serum concentration of Propafenone.  | 
		
| 
			 Silodosin  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Silodosin.  | 
		
| 
			 Simeprevir  | 
			
			 May increase the serum concentration of Propafenone.  | 
		
| 
			 St John's Wort  | 
			
			 May decrease the serum concentration of Propafenone.  | 
		
| 
			 Talazoparib  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Talazoparib. Management: These listed exceptions are discussed in detail in separate interaction monographs.  | 
		
| 
			 Tegaserod  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Tegaserod.  | 
		
| 
			 Terlipressin  | 
			
			 May enhance the bradycardic effect of Bradycardia-Causing Agents.  | 
		
| 
			 Theophylline Derivatives  | 
			
			 Propafenone may increase the serum concentration of Theophylline Derivatives. Exceptions: Dyphylline.  | 
		
| 
			 Tofacitinib  | 
			
			 May enhance the bradycardic effect of Bradycardia-Causing Agents.  | 
		
| 
			 Venlafaxine  | 
			
			 Propafenone may increase the serum concentration of Venlafaxine. Management: Monitor for increased venlafaxine levels/adverse effects (e.g., hallucinations, agitation, confusion) with propafenone initiation/dose increase. Conversely, monitor for decreased venlafaxine levels with profapenone discontinuation/dose decrease.  | 
		
| 
			 Vitamin K Antagonists (eg, warfarin)  | 
			
			 Propafenone may increase the serum concentration of Vitamin K Antagonists.  | 
		
| 
			 Risk Factor D (Consider therapy modification)  | 
		|
| 
			 Abiraterone Acetate  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of abiraterone with CYP2D6 substrates that have a narrow therapeutic index whenever possible. When concurrent use is not avoidable, monitor patients closely for signs/symptoms of toxicity.  | 
		
| 
			 Afatinib  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Afatinib. Management: Reduce afatinib by 10 mg if not tolerated. Some non-US labeling recommends avoiding combination if possible. Iif used, administer the P-gp inhibitor simultaneously with or after the dose of afatinib.  | 
		
| 
			 Amiodarone  | 
			
			 May enhance the QTc-prolonging effect of Propafenone. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 Betrixaban  | 
			|
| 
			 Bilastine  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Bilastine. Management: Consider alternatives when possible; bilastine should be avoided in patients with moderate to severe renal insufficiency who are receiving p-glycoprotein inhibitors.  | 
		
| 
			 Colchicine  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Colchicine. Colchicine distribution into certain tissues (e.g., brain) may also be increased. Management: Colchicine is contraindicated in patients with impaired renal or hepatic function who are also receiving a p-glycoprotein inhibitor. In those with normal renal and hepatic function, reduce colchicine dose as directed. See full monograph for details.  | 
		
| 
			 CYP2D6 Inhibitors (Strong)  | 
			
			 May decrease the metabolism of CYP2D6 Substrates (High risk with Inhibitors).  | 
		
| 
			 Dabigatran Etexilate  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase serum concentrations of the active metabolite(s) of Dabigatran Etexilate. Management: Dabigatran dose reductions may be needed. Specific recommendations vary considerably according to US vs Canadian labeling, specific P-gp inhibitor, renal function, and indication for dabigatran treatment. Refer to full monograph or dabigatran labeling.  | 
		
| 
			 Dacomitinib  | 
			
			 May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of dacomitinib with CYP2D6 subtrates that have a narrow therapeutic index.  | 
		
| 
			 Domperidone  | 
			
			 QT-prolonging Agents (Moderate Risk) may enhance the QTc-prolonging effect of Domperidone. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 DOXOrubicin (Conventional)  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of DOXOrubicin (Conventional). Management: Seek alternatives to P-glycoprotein inhibitors in patients treated with doxorubicin whenever possible. One U.S. manufacturer (Pfizer Inc.) recommends that these combinations be avoided.  | 
		
| 
			 Edoxaban  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Edoxaban. Management: See full monograph for details. Reduced doses are recommended for patients receiving edoxaban for venous thromboembolism in combination with certain P-gp inhibitors. Similar dose adjustment is not recommended for edoxaban use in atrial fibrillation.  | 
		
| 
			 Lefamulin  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin tablets with P-glycoprotein/ABCB1 inhibitors. If concomitant use is required, monitor for lefamulin adverse effects.  | 
		
| 
			 Methadone  | 
			
			 Propafenone may enhance the QTc-prolonging effect of Methadone. Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Class IA Antiarrhythmics (Highest Risk)  | 
			
			 Propafenone may enhance the QTcprolonging effect of QT-prolonging Class IA Antiarrhythmics (Highest Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Class III Antiarrhythmics (Highest Risk)  | 
			
			 Propafenone may enhance the QTcprolonging effect of QT-prolonging Class III Antiarrhythmics (Highest Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Kinase Inhibitors (Highest Risk)  | 
			
			 Propafenone may enhance the QTc-prolonging effect of QT-prolonging Kinase Inhibitors (Highest Risk). Management: Consider alternatives to this drug combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 QT-prolonging Miscellaneous Agents (Highest Risk)  | 
			
			 Propafenone may enhance the QTcprolonging effect of QT-prolonging Miscellaneous Agents (Highest Risk). Management: Consider alternatives to this combination. If combined, monitor for QTc interval prolongation and ventricular arrhythmias. Patients with additional risk factors for QTc prolongation may be at even higher risk.  | 
		
| 
			 Siponimod  | 
			
			 Bradycardia-Causing Agents may enhance the bradycardic effect of Siponimod. Management: Avoid coadministration of siponimod with drugs that may cause bradycardia.  | 
		
| 
			 TiZANidine  | 
			
			 CYP1A2 Inhibitors (Weak) may increase the serum concentration of TiZANidine. Management: Avoid these combinations when possible. If combined use is necessary, initiate tizanidine at an adult dose of 2 mg and increase in 2 to 4 mg increments based on patient response. Monitor for increased effects of tizanidine, including adverse reactions.  | 
		
| 
			 Venetoclax  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Venetoclax. Management: Consider a venetoclax dose reduction by at least 50% in patients requiring concomitant treatment with P-glycoprotein (P-gp) inhibitors.  | 
		
| 
			 Risk Factor X (Avoid combination)  | 
		|
| 
			 Asunaprevir  | 
			
			 May increase the serum concentration of Propafenone.  | 
		
| 
			 Fosamprenavir  | 
			
			 May increase the serum concentration of Propafenone. Management: Concurrent use of ritonavir-boosted fosamprenavir with propafenone is contraindicated. The use of non-ritonavir-boosted fosamprenavir with propafenone is not specifically contraindicated but should only be undertaken with caution.  | 
		
| 
			 PAZOPanib  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of PAZOPanib.  | 
		
| 
			 Pimozide  | 
			
			 May enhance the QTc-prolonging effect of QT-prolonging Agents (Moderate Risk).  | 
		
| 
			 Ritonavir  | 
			
			 May increase the serum concentration of Propafenone.  | 
		
| 
			 Tipranavir  | 
			
			 May increase the serum concentration of Propafenone.  | 
		
| 
			 Topotecan  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of Topotecan.  | 
		
| 
			 VinCRIStine (Liposomal)  | 
			
			 P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of VinCRIStine (Liposomal).  | 
		
Monitoring parameters:
- BP
 - Pulse
 - ECG
 
How to administer Propafenone (Rythmol)?
- Capsules should be taken orally swallowed as a whole without regards to food, without crushing or chewing.
 - The Canadian labeling recommends the tablet be swallowed whole with liquid and to be administered with food.
 
Mechanism of action of Propafenone (Rythmol):
- Propafenone, a class 1c antiarrhythmic drug, has local anesthetic properties.
 - It slows down the rate of action and blocks the fast-inward sodium current.
 - It prolongs conduction and refractoriness in all myocardium areas, focusing primarily on intraventricular conduction.
 - It can cause spontaneous automaticity reductions and prolonged refractory periods. Additionally, it may exhibit some beta-blockade activity.
 
Absorption: Well absorbed
Protein binding: 95% to alpha -acid glycoprotein
Metabolism: occurs in the liver via CYP2D6, CYP3A4, and CYP1A2 to two active metabolites (5hydroxypropafenone and N-depropylpropafenone) then ultimately to glucuronide or sulfate conjugates. Two genetically determined metabolism groups exist (extensive and poor metabolizers); 10% of Caucasians are poor metabolizers. Exhibits nonlinear pharmacokinetics. Serum concentrations are increased to tenfold when the dose is increased from 300-900 mg/day, this nonlinearity is thought to be due to saturable first-pass effect.
Bioavailability:
- Immediate release (IR): 150 mg: 3.4%; 300 mg: 10.6%; relative bioavailability of extended-release (ER) capsule is less than immediate-release tablet; The bioavailability of an ER capsule regimen of 325 mg twice-daily regimen approximates an IR tablet regimen of 150 mg 3 times/day.
 
Half-life elimination:
- Extensive metabolizers: 2-10 hours
 - Poor metabolizers: 10-32 hours
 
The time to reach peak serum concentration:
- Immediate-release: 3.5 hours
 - Extended-release: 3-8 hours
 
Excretion: Urine (<1% unchanged; remainder as glucuronide or sulfate conjugates); feces
Propafenone Brand Names (International):
- Rythmol SR
 - Rythmol
 - APO-Propafenone
 - MYL-Propafenone
 - MYLAN-Propafenone
 - NU-Propafenone
 - PMSPropafenone
 - Propafenone-150
 - Propafenone-300
 - Arythmol
 - Nistaken
 - Norfenon
 - Normapafenone
 - Normorytmin
 - Profex
 - Pronon
 - Propafen
 - Propafenon Genericon
 - Propafenon Pharmavit
 - Propanorm
 - Prorynorm
 - Rhythmonorm
 - Ritmocor
 - Ritmonorm
 - Rythmex
 - Rythmol
 - Rythmonorm
 - Rythmosin
 - Rytmocard
 - Rytmol
 - Rytmonorm
 - Rytmonorma
 - Ryytmonorm
 
Propafenon Brand Names in Pakistan:
No Brands Available in Pakistan.