1. ¹Community Consortium, Positive Health Program, San Francisco General Hospital, San Francisco, California, USA
2. ²Division of Hematology-Oncology, San Francisco General Hospital, San Francisco, California, USA
3. ³Department of Medicine, University of California, San Francisco, California, USA
4. ⁴Division of Neurology, San Francisco General Hospital, San Francisco, California, USA
5. ⁵Department of Neurology, University of California, San Francisco, California, USA
6. ⁶Division of Clinical Pharmacology and Experimental Therapeutics, University of California, San Francisco, California, USA

Correspondence: DI Abrams, (dabrams@php.ucsf.edu)

Received 29 September 2006; Accepted 25 February 2007; Published online 11 April 2007.

Abstract

Although cannabis may have potential therapeutic value, inhalation of a combustion product is an undesirable delivery system. The aim of the study was to investigate vaporization using the Volcano^® device as an alternative means of delivery of inhaled Cannabis sativa. Eighteen healthy inpatient subjects enrolled to compare the delivery of cannabinoids by vaporization to marijuana smoked in a standard cigarette. One strength (1.7, 3.4, or 6.8% tetrahydrocannabinol (THC)) and delivery system was randomly assigned for each of the 6 study days. Plasma concentrations of -9-THC, expired carbon monoxide (CO), physiologic and neuropsychologic effects were the main outcome measures. Peak plasma concentrations and 6-h area under the plasma concentration–time curve of THC were similar. CO levels were reduced with vaporization. No adverse events occurred. Vaporization of cannabis is a safe and effective mode of delivery of THC. Further trials of clinical effectiveness of cannabis could utilize vaporization as a smokeless delivery system.