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Propafenone hydrochloride tablets


Oral formulations of propafenone hydrochloride.

Drugs List

  • ARYTHMOL 150mg tablets
  • ARYTHMOL 300mg tablets
  • propafenone 150mg tablets
  • propafenone 300mg tablets
  • Therapeutic Indications


    Paroxysmal supra-ventricular tachyarrhythmias
    Ventricular arrhythmias

    Prophylaxis and treatment of ventricular arrhythmias.
    Prophylaxis and treatment of paroxysmal supraventricular tachyarrhythmias when standard therapy has failed or is contraindicated.


    Treatment with propafenone hydrochloride should be initiated under hospital conditions under the supervision of a physician experienced in the treatment of arrhythmias.

    Dose increases should not be attempted until the patient has been receiving treatment for three to four days.

    A reduction in dose should be considered for patients weighing less than 70kg.

    Cardiological surveillance, including ECG monitoring and blood pressure control, should be used to determine individual maintenance doses.


    Initially 150mg three times daily. This dose may be increased at a minimum of three day intervals to 300mg twice daily and, if necessary, to 300mg three times daily. This dose should not be exceeded.


    Treatment should be initiated gradually.

    Higher plasma concentrations of propafenone hydrochloride have been noted in the elderly who may, therefore, respond to a lower dose; for this reason elderly patients should be carefully monitored.

    Any dose increase that may be required should not be undertaken until after five to eight days of therapy.

    Patients with Renal Impairment

    Dose adjustment may be necessary in renal impairment patients, due to a possible drug accumulation after standard therapeutic doses.

    Titration of dose necessitates ECG and plasma level monitoring.

    Patients with Hepatic Impairment

    Dose adjustment may be necessary in hepatic impairment patients, due to a possible drug accumulation after standard therapeutic doses.

    Titration of dose necessitates ECG and plasma level monitoring.

    Additional Dosage Information

    If the QRS interval is prolonged by more than 20%, the dose should be reduced or propafenone hydrochloride discontinued until the ECG returns to normal limits.


    Children under 18 years
    Brugada syndrome
    Bundle branch block where no pacing rescue available
    Electrolyte imbalance
    Long QT syndrome
    Myasthenia gravis
    Non paced atrial conduction defects
    Non paced second/third degree AV block
    Non-arrhythmia induced cardiogenic shock
    Non-paced infrahisian block
    Non-paced sinus node dysfunction
    Severe bradycardia
    Severe hypotension
    Severe obstructive pulmonary disease
    Severe structural cardiac disorder
    Torsade de pointes
    Uncontrolled congestive cardiac failure with LVEF below 35%
    Within 3 months of a myocardial infarction

    Precautions and Warnings

    Family history of long QT syndrome
    Predisposition to cardiac failure
    Weight below 70kg
    Atrial fibrillation
    Cardiac pacemaker
    Hepatic impairment
    History of torsade de pointes
    Obstructive pulmonary disease
    Renal impairment

    Consider dosage modification in patients with pacemakers
    Advise patient ability to drive or operate machinery may be impaired
    Treatment to be initiated and supervised by a specialist
    Perform ECG before and during treatment
    Consider dose reduction in patients under 70kg
    Monitor blood pressure during titration and early maintenance treatment
    Monitor serum electrolytes
    May convert atrial fibrillation to atrial flutter
    Discontinue or reduce dose if QRS is prolonged by more than 20%
    Advise patient to avoid grapefruit products

    A Brugada syndrome may be unmasked or Brugada like ECG changes may be provoked after exposure to propafenone hydrochloride in previously asymptomatic carriers of the syndrome. An ECG should be performed after initiating therapy with propafenone hydrochloride to rule out Brugada syndrome.

    There is a potential for conversion of paroxysmal atrial fibrillation to atrial flutter with accompanying 2:1 or 1:1 conduction block.

    Pregnancy and Lactation


    Use propafenone with caution in pregnancy.

    Propafenone crosses the placenta, the concentration of propafenone in the umbilical cord has been shown to be approximately 30% of that in maternal blood.

    Animal studies in rats and rabbits showed no teratogenic effects, however embryotoxicity occurred when given at doses 10 and 40 times the maximum recommended human doses.

    Schaefer (2015) includes propafenone as one of the antiarrhythmic class 1C drugs of choice for the treatment of pregnant women but emphasizes the importance of critically evaluating the indication for use because antiarrhythmic agents themselves may cause arrhythmia.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Use propafenone with caution in breastfeeding.

    Propafenone is excreted into breast milk. Limited information indicates that maternal doses of propafenone hydrochloride of up to 900mg daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Abdominal distension
    Abdominal pain
    Atrial flutter
    Atrioventricular block
    Blood dyscrasias
    Blurred vision
    Cardiac failure
    Changes in hepatic function
    Chest pain
    Conduction disturbances
    Decreased appetite
    Dry mouth
    Elevation of liver enzymes
    Erectile dysfunction
    Exacerbation of pre-existing asthma
    Extrapyramidal effects
    Gastro-intestinal disturbances
    Hepatocellular damage
    Hypersensitivity reactions
    Intraventricular block
    Lupus erythematosus-like syndrome
    Postural hypotension
    Pro-arrhythmic effects
    Reduction in spermatogenesis (in male)
    Sino-atrial block
    Sleep disturbances
    Ventricular fibrillation
    Ventricular tachycardia
    Worsening heart failure


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: April 2018.

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Medications and Mothers' Milk, 14th Edition (2010) Hale, T. Hale Publishing, Amarillo, Texas.

    NICE Evidence Services Available at: Last accessed: 23 April 2018.

    Summary of Product Characteristics: Arythmol 150mg tablets. Mylan Products Limited. Revised June 2017.

    Summary of Product Characteristics: Arythmol 300mg tablets. Mylan Products Limited. Revised June 2017.

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Propafenone. Last revised: 10 March 2015.
    Last accessed: 23 March 2018.

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