The Clinical Pharmacology of Intranasal l-Methamphetamine
1 Addiction Pharmacology Research Laboratory, The California Pacific Medical Center Research Institute, St. Luke's Hospital, 7th floor, 3555 Cesar Chavez Street, San Francisco, CA 94110, USA
2 Drs. McGlothin and Foster: Department of Cardiology, University of California, San Francisco, 401 Parnassus Avenue, San Francisco, CA 94143-0984, USA
3 Department of Psychiatry, University of Cincinnati and Cincinnati VA Medical Center, 3200 Vine St Cincinnati, Ohio, 45220, USA
4 Department of Psychiatry, University of California, San Francisco, 401 Parnassus Avenue, San Francisco, CA 94143-0984, USA
BMC Clinical Pharmacology 2008, 8:4 doi:10.1186/1472-6904-8-4Published: 21 July 2008
We studied the pharmacology of l-methamphetamine, the less abused isomer, when used as a nasal decongestant.
12 subjects self-administered l-methamphetamine from a nonprescription inhaler at the recommended dose (16 inhalations over 6 hours) then at 2 and 4 (32 and 64 inhalations) times this dose. In a separate session intravenous phenylephrine (200 μg) and l-methamphetamine (5 mg) were given to define alpha agonist pharmacology and bioavailability. Physiological, cardiovascular, pharmacokinetic, and subjective effects were measured.
Plasma l-methamphetamine levels were often below the level of quantification so bioavailability was estimated by comparing urinary excretion of the intravenous and inhaled doses, yielding delivered dose estimates of 74.0 ± 56.1, 124.7 ± 106.6, and 268.1 ± 220.5 μg for ascending exposures (mean 4.2 ± 3.3 μg/inhalation). Physiological changes were minimal and not dose-dependent. Small decreases in stroke volume and cardiac output suggesting mild cardiodepression were seen.
Inhaled l-methamphetamine delivered from a non-prescription product produced minimal effects but may be a cardiodepressant.