Abstract

Objective: To study the effects of over-the-counter dosages of the pure alpha-agonists pseudoephedrine (PSE) and phenylpropanolamine (PPA) on selected parameters of exercise performance, and to establish a range of corresponding drug levels in the urine of the athletes who use these drugs. Design: Placebo-controlled, randomized, double-blinded, multiple-dose trial. Participants: A convenience sample of 20 male cyclists, aged 18-35, from the local cycling community. Inclusion criteria required cycling at least 50 miles a week, no chronic medical problems, and not taking any medications. Subjects were recruited by local ads and word of mouth. Intervention: Patients were randomized to one of two groups of 10 subjects. Each subject in both groups performed three separate bicycle ergometer tests after ingestion of varying dosages of alpha-agonists. One group performed tests after receiving placebo, 0.33 mg/kg PPA, and 0.66 mg/kg PPA, whereas the other group received placebo, 1 mg/kg PSE, and 2 mg/kg PSE. A minimum 1-week washout period was required between tests. Urine for drug testing was collected 1 h before, immediately afterward, and the next morning after testing. Drug testing was performed by gas GC/MCD at a facility approved by the International Olympic Committee. Main outcome measures: Maximum oxygen uptake (VO2max), time to exhaustion, urine drug levels of PSE and PPA, peak blood pressures (BPs), peak pulse, and Borg scale (rating of perceived exertion or RPE). Conclusions: We found no significant differences between trials in maximum oxygen uptake (VO2max), peak or progression of Borg Scale (RPE), maximum systolic and diastolic BPs, peak pulse, or time to exhaustion among the athletes tested at the dosages studied. Urine drug levels in athletes taking one and two times the over-the-counter dosages of PPA and PSE in all cases exceeded allowable limits according to International Olympic Committee drug-testing standards. Verf.-Referat (gekuerzt)