Токаинид

Использование

Tocainide is used for suppressing symptoms of ventricular arrhythmia and tachycardia, and for premature cardiac contractions.

Определение

ChEBI: A monocarboxylic acid amide in which 2,6-dimethylphenylaniline and isobutyric acid have combined to form the amide bond; used as a local anaesthetic.

Всемирная организация здравоохранения(ВОЗ)

Tocainide, an antidysrhythmic agent, was introduced in 1981 for the treatment of ventricular dysrhythmias. By 1984 its use was associated with cases of agranulocytosis, aplastic anaemia and thrombocytopenia, some of which were fatal. This led some regulatory authorities to restrict the indications for its use. The major manufacturer has subsequently restricted its use on a worldwide basis to the treatment of symptomatic ventricular dysrhythmias not responding to other therapy, or when other therapy is contraindicated.

Фармакокине?тика

The α-methyl group is believed to slow the rate of metabolism and, thereby, to contribute to oral activity. The plasma half-life of tocainide is approximately 12 hours, and nearly 50% of the drug may be excreted unchanged in the urine. Adverse effects associated with tocainide are like those observed with lidocaine—specifically, gastrointestinal disturbances and central nervous system effects.

Клиническое использование

Tocainide (Tonocard) is an orally effective antiarrhythmic agent with close structural similarities to lidocaine. Tocainide is indicated for the treatment of symptomatic ventricular arrhythmias refractory to more conventional therapy. Serious noncardiac adverse effects limit its use to patients with life-threatening arrhythmias.

Побочные эффекты

Light-headedness, dizziness, or nausea occurs in approximately 15% of patients, paresthesias and numbness in 9%, and tremor in 8%.These adverse effects are generally mild in intensity, transient, and dose related. Overall, however, approximately 20% of patients prescribed tocainide discontinue therapy because of such effects. Serious immune-based side effects, such as pulmonary fibrosis, have been reported, and blood dyscrasias, such as agranulocytosis and thrombocytopenia, may occur in up to 0.2% of patients.

взаимодействия лекарств

When used with other class IB antiarrhythmic drugs, tocainide toxicity may be increased without significant gain in antiarrhythmic efficacy.

Меры предосторожности

Patients who are hypersensitive to tocainide or to local anesthetics of the amide type should not be exposed to tocainide.The presence of second- or third-degree heart block in the absence of an artificial pacemaker also contraindicates the use of tocainide.