Effect of alcohol on propylthiouracil disposition.

We examined the effect of ethanol on propylthiouracil (PTU) disposition in normal subjects and a rabbit. The drug is metabolized by conjugation. In six normal subjects 19.2 gm oral ethanol, taken either with or two hr after 300 mg PTU, did not change maximum concentration, time to maximum concentration, or total or free AUC of PTU. Pretreatment with ethanol and supplementation to keep blood ethanol concentration above 800 mg/l for 8 hr also did not alter PTU disposition. In the rabbit, the infusion of ethanol (8.81 mg/min) 4 hr after the beginning of an intravenous infusion of PTU 0.05 mg/min did not alter the plasma concentration profile. These results indicate that short-term ethanol dosing does not affect PTU disposition and therefore dosage adjustment is not necessary in patients who drink alcohol.