新しい抗不整脈薬Aprindine内服による血中濃度と抗不整脈効果

Clinical efficacy and plasma levels of oral Aprindine, a new antiarrhythmic drug

　アプリンジンは最近ベルギーで開発された静脈内，並びに経口投与可能な新しい抗不整脈剤で，心室性期外収縮（PVC）の他，心房性期外収縮（PAC），心室性頻拍症（VT），上室性頻拍症（SVT）に効果があるとされている。本剤は，また血中消失半減期が長く，その作用が持続性であることも注目されているが，本邦ではその抗不整脈作用と血中濃度との関係を詳細にみた報告はない。今回我々は，アプリンジンの経口投与による抗不整脈作用と血中濃度の推移を詳細にみたので報告する。

The clinical efficacy and the plasma levels of Aprindine, a new antiarrhythmic drug were tested in nine patients, of which eight were suffering from premature ventricular contraction (PVC) and one from supraventricular tachycardia (SVT).

The drug was given orally in daily doses of 50 mg (two cases) to 100 mg (seven cases) for 7 (five cases), 8, 9, 15 or 20 (each one case) days. An excellent clinical response was obtained in oneSVT case and in seven PVC cases. In the remain-ing PVC case, a good result was demonstrated.

Aprindine was found to be effective when its plasma levels were between 0.25μg iml and 1.25 μg/ml. Peak plasma levels varied from 0.7μg/ml to 2.1μg/ml, and the half-life was estimated tobe 46.3±7.5hours, which is longer than that reported previously in Europe. Neurological (diz-ziness: 1 case, tremor: 1 case) and hematological (leucopenia: 1 case) side effects were observed, but they disappeared immediately on discontinua-tion of Aprindine medication.