Physiological and pharmacokinetic effects of oral 1,3-dimethylamylamine administration in men

Background: 1,3-dimethylamylamine (DMAA) has been a component of dietary supplements and is also used within party pills, often in conjunction with alcohol and other drugs. Ingestion of higher than recommended doses results in untoward effects including cerebral hemorrhage. To our knowledge, no studies have been conducted to determine both the pharmacokinetic profile and physiologic responses of DMAA. Methods: Eight men reported to the lab in the morning following an overnight fast and received a single 25 mg oral dose of DMAA. Blood samples were collected before and through 24 hours post-DMAA ingestion and analyzed for plasma DMAA concentration using high-performance liquid chromatography-mass spectrometry. Resting heart rate, blood pressure, and body temperature was also measured. Results: One subject was excluded from the data analysis due to abnormal DMAA levels. Analysis of the remaining seven participants showed DMAA had an oral clearance of 20.02 +/- 5 L. hr(-1), an oral volume of distribution of 236 +/- 38 L, and terminal half-life of 8.45 +/- 1.9 hr. Lag time, the delay in appearance of DMAA in the circulation following extravascular administration, varied among participants but averaged approximately 8 minutes (0.14 +/- 0.13 hr). The peak DMAA concentration for all subjects was observed within 3-5 hours following ingestion and was very similar across subjects, with a mean of similar to 70 ng . mL(-1). Heart rate, blood pressure, and body temperature were largely unaffected by DMAA treatment. Conclusions: These are the first data to characterize the oral pharmacokinetic profile of DMAA. These findings indicate a consistent pattern of increase across subjects with regards to peak DMAA concentration, with peak values approximately 15-30 times lower than those reported in case studies linking DMAA intake with adverse events. Finally, a single 25 mg dose of DMAA does not meaningfully impact resting heart rate, blood pressure, or body temperature.