Propafenone: Effects, Uses & Risks

Propafenone is a well-known active ingredient used to combat cardiac arrhythmias. Due to its chemical and pharmacological properties, propafenone is assigned to the antiarrhythmic drug class. The drug has been in use for several years and is considered to be very effective.

What is propafenone?

Propafenone is a well-known drug used for the therapy of various cardiac arrhythmias. In Germany, Austria, and Switzerland, the drug is sold under the trade names Cuxafenon and Prorynorm. There is an indication for tachyarrhythmia (cardiac arrhythmia that occurs in combination with an excessively fast heartbeat) as well as ventricular tachycardia (cardiac arrhythmia that coincides with an increased heart rate) and atrial fibrillation. It should be noted that the dose administered depends on the underlying disease requiring treatment. In chemistry, propafenone is described by the molecular formula C 21 – H 27 – N – O 3. This corresponds to a moral mass of about 341.44 g/mol. Due to its chemical and pharmacological properties, propafenone is assigned to the group of so-called antiarrhythmics. These are not necessarily related agents that affect cardiac rhythm. In accordance with the classification commonly used in the medical and pharmacological literature according to E. Vaughan Williams, a distinction can be made between four classes of antiarrhythmic drugs. According to this classification, propafenone falls into the first class, under which various sodium channel blockers are grouped. Differentiated further, propafenone is a representative of class Ic, which also includes the related drug flecainide.

Pharmacologic effects on the body and organs

The pharmacologic properties of propafenone largely correspond to those of a typical antiarrhythmic drug. The medical drug is considered a sodium channel antagonist. As such, it leads to a slowing of the influx of sodium ions. After taking propafenone, these ions can no longer enter the myocardium, the layer of heart muscle tissue located between the inner and outer layers of the heart, undisturbed. This results in a noticeable decrease in the excitability of the heart. The mechanism of action of propafenone is therefore referred to as bathmotropic. In addition to slowing the influx of sodium ions, propafenone also causes a blockade of beta receptors. This also results in an influence on the speed of the heart rate. After proper and continuous intake, propafenone is present in the blood up to 97% in bound form on plasma proteins. The plasma half-life of propafenone has been reported in studies to average between three and six hours. Propafenone is metabolized (metabolized) primarily by the liver.

Medicinal use and use for treatment and prevention.

Propafenone is used exclusively to control cardiac arrhythmias. However, unlike some other medications, propafenone can be used for a variety of forms. Thus, there is an indication for both tachyarrhythmia and ventricular tachycardia. It can also be used to treat atrial fibrillation. Propafenone is sold under various trade names in Germany, Austria and Switzerland, as there is more than one manufacturer. The most common preparations include Cuxafenon and Prorynorm. They are only available as film-coated tablets. In addition, propafenone is subject to pharmacy and prescription requirements. It can therefore only be taken after a doctor’s prescription and is only available in pharmacies. As a Class Ic antiarrhythmic drug, propafenone must be taken several times to achieve consistent efficacy. In general, it is recommended that propafenone be taken orally two to three times daily (depending on dosage). This dosage recommendation is typical for Class Ic.

Risks and side effects

Propafenone should not be taken if there is a contraindication. This technical term refers to a circumstance in which, from a medical point of view, it is mandatory to refrain from taking the drug because of the existence of a contraindication. This is the case when hypersensitivity or allergy is known, AV or sinus node dysfunction exists, heart failure is present, or hypotension exists.In addition, a contraindication is also given during pregnancy and lactation. Severe asthmatics must also not take propafenone. This also applies to people suffering from severe damage to the liver, as this is primarily responsible for the breakdown of the active substance. Propafenone is also contraindicated in cases of potassium imbalance and during the first three months after a heart attack. Furthermore, undesirable side effects may occur even when propafenone is taken properly. However, this is not necessarily the case. The majority of intakes remain free of side effects. Also, never all of the symptoms under consideration occur at once. In studies, chest pain, dry mouth, and gastrointestinal disorders (constipation, nausea, or vomiting) in particular have been associated with propafenone use. Other typical side effects include headache and dizziness, as well as changes in preexisting cardiac arrhythmias.