A comparison of the bioavailabilities of oral and intravenous ethanol in healthy male volunteers

Objectives: Ethanol (EtOH), the antidote for methanol and ethylene glycol, is administered by the oral (PO) and intravenous (IV) routes. Serum concent rations (SCs) of 100 mg/dL or more are targeted for clinical effect. This s tudy was completed to validate the assumption that there are minimal differ ences in SC achieved between these two routes. Methods: Twenty healthy male volunteers were randomized to receive either PO or IV EtOH. Subjects absta ined from EtOH for 48 hours before each phase. After a seven-day washout pe riod, the subjects crossed over to the other group. Inclusion criteria were no history of medical problems, age between 21 and 40 years, and actual bo dy weight within 10% of ideal weight. Baseline EtOH SCs were obtained befor e participation in each phase. Two hours after a standard breakfast, the su bjects received 700 mg/kg of PO or IV EtOH. PO EtOH was administered as a 2 0% solution in juice over 10 minutes. IV EtOH, controlled by an infusion pu mp, was administered as a 10% solution over 30 minutes. Blood was drawn for EtOH SCs at 45, 75, 105, 135, 165, 225, 285, and 345 minutes after start o f the dose. Results: All initial EtOH SCs were 0. EtOH SCs were higher afte r IV administration. Mean peak SC was 103.6 mg/dL after IV administration a nd 71.3 mg/dL after PO administration (p < 0.0001). Mean time to peak was 4 6.5 minutes after TV administration and 103.5 minutes after PO administrati on (p < 0.0001). Total area under the curve was 17,440 min-mg/dl after IV a dministration and 13,875 min-mg/dl after PO administration (p < 0.003). The order of treatments did not affect results (p > 0.1). Conclusion: Signific ant differences exist between the SCs of EtOH as well as the times to peak SC after PO and IV administrations.