Wittekind H H, Testa B, Balant L P
Eur J Drug Metab Pharmacokinet. 1984 Apr-Jun;9(2):117-22. doi: 10.1007/BF03189614.
Proxibarbal and valofan are tautomeric drugs which interconvert rapidly in solution. In the present study, the urinary excretion of these two drugs was investigated in two subjects after separate oral administration. In both cases, only proxibarbal was found in urine, while the excretion of valofan was negligible or non-detectable. More than half of a dose remains unaccounted for after proxibarbal administration, and more than three quarters after valofan administration. A simple chemical equilibrium of tautomerism as found in vitro is insufficient to account for the excretion kinetics of the two drugs in humans.
普罗西巴比妥和戊双胺是互变异构药物，在溶液中能迅速相互转化。在本研究中，对两名受试者分别口服这两种药物后的尿液排泄情况进行了调查。在这两种情况下，尿液中仅发现了普罗西巴比妥，而戊双胺的排泄量可忽略不计或无法检测到。服用普罗西巴比妥后，超过一半的剂量去向不明，服用戊双胺后则超过四分之三。体外发现的简单互变异构化学平衡不足以解释这两种药物在人体中的排泄动力学。
