Volume 74, Issue 5 p. 475-486
Pharmacokinetics and Drug Disposition

The bioavailability of intranasal and smoked methamphetamine

Debra S. Harris MD

Debra S. Harris MD

Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco, Calif, USA

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Harold Boxenbaum PhD

Harold Boxenbaum PhD

Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco, Calif, USA

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E. Thomas Everhart PhD

E. Thomas Everhart PhD

Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco, Calif, USA

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Gina Sequeira MS

Gina Sequeira MS

Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco, Calif, USA

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John E. Mendelson MD

Corresponding Author

John E. Mendelson MD

Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco, Calif, USA

Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco, 401 Parnassus Ave, San Francisco, CA 94143-0984, USA. E-mail: [email protected]Search for more papers by this author
Reese T. Jones MD

Reese T. Jones MD

Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco, Calif, USA

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First published: 27 November 2003
Citations: 14

Abstract

Background

Patients in harm-reduction treatment programs are switching from intravenous to otherroutes of methamphetamine (INN, metamfetamine) administration to avoid risks associated with needle use. Relatively little has been reported about the bioavailability of methamphetamine when smoked or used intranasally.

Methods

Eight experienced methamphetamine users were administered smoked or intranasal methamphetamine concurrently with an intravenous dose of deuterium-labeled methamphetamine. Plasma and urine concentrations were measured for calculation of bioavailability and other pharmacokinetic parameters by noncompartmental methods.

Results

Methamphetamine was well absorbed after smoking or intranasal administration, with bioavailabilities of 79% after intranasal administration and 67% of the estimated delivered dose or 37.4% of the absolute (pipe) dose after smoking. Maximum methamphetamine concentrations occurred at 2.7 and 2.5 hours after intranasal and smoked doses. The elimination half-life was similar for intravenous (11.4 hours), intranasal (10.7 hours), and smoked (10.7 hours) methamphetamine. Clearance (272 mL · h−1 · kg−1), steady-state volume of distribution (4.2 L/kg), and mean residence time (16 hours) of the intravenous dose were similar to previously reported values. Dextroamphetamine (INN, dexamfetamine) half-life (all routes)was 16.2 hours. Methamphetamine and dextroamphetamine renal clearances (all routes) were about 100 and 1100 mL · h−1 · kg−1, respectively.

Conclusions

Intranasal and smoked methamphetamine are well absorbed. Although intranasal or smoked routes may decrease the risk of transmission of blood-borne diseases, exposure to methamphetamine and the possibility of drug-related complications remain substantial.

Clinical Pharmacology & Therapeutics (2003) 74, 475–486; doi: 10.1016/j.clpt.2003.08.002