Loi C M, Wei X, Parker B M, Korrapati M R, Vestal R E
Clinical Pharmacology and Gerontology Research Unit, Department of Veterans Affairs Medical Center, Boise, ID 83702.
Br J Clin Pharmacol. 1993 Apr;35(4):437-40. doi: 10.1111/j.1365-2125.1993.tb04163.x.
The effect of 5 days of oral tocainide (400 mg every 8 h) on the kinetics of theophylline given as a single 5 mg kg-1 i.v. infusion over 30 min was investigated in eight healthy male nonsmokers. Treatment with tocainide decreased the plasma clearance of theophylline from 37.5 +/- 6.9 (mean +/- s.d.) to 33.7 +/- 5.0 ml kg-1 h-1 (difference -3.8, 95% CI, -1.7 to -5.9; P = 0.004) and increased its terminal elimination half-life from 9.7 +/- 2.5 to 10.4 +/- 2.1 h (difference 0.7, 95% CI, 0.2 to 1.2; P = 0.011). Tocainide decreased the formation clearances of 3-methylxanthine and 1-methyluric acid, but the formation clearance of 1,3-dimethyluric acid was unaltered. These data indicate that tocainide exerts a modest inhibitory effect on theophylline metabolism. The magnitude of this change is substantially smaller than that reported to be produced by mexiletine.
在8名健康男性非吸烟者中，研究了口服妥卡尼5天（每8小时400毫克）对静脉注射30分钟给予单次5毫克/千克茶碱动力学的影响。妥卡尼治疗使茶碱的血浆清除率从37.5±6.9（均值±标准差）降至33.7±5.0毫升/千克/小时（差异-3.8，95%置信区间，-1.7至-5.9；P=0.004），并使其终末消除半衰期从9.7±2.5小时延长至10.4±2.1小时（差异0.7，95%置信区间，0.2至1.2；P=0.011）。妥卡尼降低了3-甲基黄嘌呤和1-甲基尿酸的生成清除率，但1,3-二甲基尿酸的生成清除率未改变。这些数据表明，妥卡尼对茶碱代谢有适度的抑制作用。这种变化的幅度明显小于美西律所产生的变化幅度。
