%0 Journal Article
%T The Clinical Pharmacology of Intranasal l-Methamphetamine
%A John E Mendelson
%A Dana McGlothlin
%A Debra S Harris
%A Elyse Foster
%A Tom Everhart
%A Peyton Jacob
%A Reese T Jones
%J BMC Pharmacology and Toxicology
%D 2008
%I BioMed Central
%R 10.1186/1472-6904-8-4
%X 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 ¦Ìg) 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 ¡À 56.1, 124.7 ¡À 106.6, and 268.1 ¡À 220.5 ¦Ìg for ascending exposures (mean 4.2 ¡À 3.3 ¦Ìg/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.There are two enantiomers of methamphetamine: dextrorotatory (d) methamphetamine and levorotatory (l) methamphetamine. The d-isomer is commonly abused and is available by prescription (DEA Schedule II), but unknown to most physicians the l-isomer is sold over-the-counter and is the active ingredient of the Vicks£¿ Vapor Inhaler (spelled levmetamfetamine by the manufacturer, Procter & Gamble, Cincinnati, OH) [1,2]. Each Vicks inhaler contains about 50 mg of l-methamphetamine, and earlier estimates suggested delivered daily doses between 1.9 to 7.2 mg of drug when used as directed [3]. The over-the-counter (OTC) vasoconstrictor nasal decongestant phenylpropanolamine (PPA) was associated with an increased risk of hemorrhagic stroke in young women that led to it being voluntarily withdrawn from the market [4]. Ephedra, another component of OTC nasal decongestants may also increase the risk of cardiovascular adverse events [5]. Methamphetamine is a sympathomimetic
%U http://www.biomedcentral.com/1472-6904/8/4