A Randomized Crossover Study to Determine the Pharmacokinetics of Intranasally Administered Acetaminophen in Healthy Adults

This study is aimed at addressing a significant void in the current literature regarding nasally administered acetaminophen pharmacokinetics. The pharmacokinetics of acetaminophen following oral and rectal administration have been well studied but to date there are no published studies determining the pharmacokinetics of acetaminophen following intranasal administration. This route is currently popular among heroin users. Understanding the pharmacokinetics of nasally administered acetaminophen will help physicians address the important clinical implications of acetaminophen toxicity in this population.

Ten healthy adult volunteers age 18 to 45 years will be recruited for this pilot project. Study participants will be randomized in permuted blocks to receive either oral or intranasal administration of a standardized 500 mg dose of acetaminophen. Blood samples will be drawn from a peripheral intravenous catheter at 0, 5, 15, 30, 45, 60, 90, 120, 150, 240, 360, and 480 minutes after study drug administration and sent to the laboratory for determination of serum acetaminophen concentration. After a one week washout period, each participant will cross over to receive 500 mg of acetaminophen via the remaining route of administration in the second arm of the study. The serial acetaminophen concentrations will be utilized to perform pharmacokinetic calculations.