[Therapeutic Drug Monitoring of Antiarrhythmic Drugs].

Antiarrhythmic drugs (AADs) can exhibit lethal adverse effects including proarrhythmia. To avoid these adverse effects, therapeutic drug monitoring (TDM) provides a therapeutic benefit. Recently, the Japanese Circulation Society and Japan TDM Society collaborated to do publish "Guidelines for TDM of Cardiovascular Drugs". Class I AADs exert strong sodium channel-blocking effects. The initial dose should be set using a nomogram. When using a beta blocker, an electrocardiogram and heat rate monitoring are more useful than TDM. Pulmonary toxicity is frequently observed in patients treated with amiodarone. TDM of amiodarone and its active metabolite desethylamiodarone is available to assess the risk of pulmonary toxicity. The ther- apeutic range of bepridil is 250-800 ng/mL. Exceeding this range may result in abnormal QT prolongation and the development of torsade de pointes. Digitalis intoxication should be avoided. Its therapeutic range partially overlaps with its toxic range. In patients with congestive heart failure, the serum concentration of digoxin should be maintained at a lower range. In summary, regarding arrhythmia therapy using AADS, safety should be more important than efficacy. Appropriate TDM is recommended. [Review].