Objective: L-methamphetamine (the non-abused isomer of methamphetamine) is banned in athletic competition because it may improve athletic performance, but there are no studies assessing its effects on performance. In the United States L-methamphetamine is formulated in the non-prescription Vick’s Vapor Inhaler (VVI) nasal decongestant. VVIs sold elsewhere (we used ones from the UK) contain similar inactive ingredients (menthol, camphor and Siberian pine oil) but no L-methamphetamine. This study tested the effects of inhaled L-methamphetamine delivered from a widely available non-prescription product on athletic performance.
Design: In a 2-session double-blind placebo-controlled study 12 participants (ages 14–17) were dosed with 4 (session 1) and 12 (session 2) inhalations from VVIs with (USA) or without (UK) L-methamphetamine and then performed two 20 minute rides on a stationary bike with rides separated by a 30 minute rest.
Outcome measure: The main outcome measure was miles travelled during each 20 minute ride. Secondary outcome measures included postride urine toxicology; heart rate and blood pressure before, 1, 5 and 10 minutes postride; energy, performance, endurance, and ability to breathe; and VVI preference. Data were analysed using Excel statistical macros.
Results: After ∼16 μg L-methamphetamine distance travelled was 5.26 (SD 0.53) miles vs 5.30 (0.55) with placebo; p = 0.81. After ∼48 μg L-methamphetamine distance travelled was 5.30 (0.51) vs 5.35 (0.43) with placebo; p = 0.85. The ∼16 μg dose increased systolic blood pressure from 72.6 (4.3) to 79.6 (6.6) mm Hg (p = 0.03) at 5 minutes postride but there were no other differences in outcomes.
Conclusions: Modest doses of inhaled L-methamphetamine probably do not improve athletic performance but do minimally raise diastolic blood pressure.
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Funding Research supported by NIH P50 DA 18179. Studies were carried out at the Addiction Pharmacology Research Laboratory at the California Pacific Research Institute, St Luke’s Hospital, San Francisco, CA. There was no study sponsor. The study design; collection, analysis, and interpretation of data; the writing of the report; and the decision to submit the article for publication were under the sole control of the authors.
Competing interests None.
Ethics approval Research ethics board of California Pacific Medical Center.
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