The effect of stress on absorption of acetaminophen.

RATIONALE: There is a large variability in the response to pharmacological treatment. Some studies have linked this variability to stress levels, i.e., stress may slow and/or reduce absorption of drugs.

OBJECTIVES

The present experiment investigated the hypothesis that stress slows absorption of drugs.

METHODS

Twenty-four volunteers participated in a within-subjects design with three conditions, each lasting 70 min. Subjects watched a movie hypothesized to induce stress, subjects listened to music hypothesized to reduce stress, and in a control condition no stimuli were presented. Each condition was spaced 2 days or more apart. In each condition, subjects received 500 mg oral acetaminophen. Measures of stress and acetaminophen levels were obtained every 10 min.

RESULTS

Indices of subjective stress and arousal and cortisol, were increased during the movie compared to control. Subjective arousal and cortisol were decreased during music compared to control. However, acetaminophen levels were the same across time in all three experimental conditions.

CONCLUSIONS

There was no effect of the experimental manipulations on acetaminophen absorption, indicating that stress was not related to drug absorption. However, stress could play a role in other processes related to drug pharmacokinetics.