Bronchial effects of aerosolized delta 9-tetrahydrocannabinol in healthy and asthmatic subjects.
Effects on airway dynamics, heart rate, and the central nervous system of various doses of delta9-tetrahydrocannabinol administered in a random, double blind fashion using a Freon-propelled, metered-dose nebulizer were evaluated in 11 healthy men and 5 asthmatic subjects. Effects of aerosolized delta9-tetrahydrocannabinol were compared with aerosolized placebo and isoproterenol and with 20 mg of oral and smoked delta9-tetrahydrocannabinol. In the normal subjects, after 5 to 20 mg of aerosolized delta9-tetrahydrocannabinol, specific airway conductance increased immediately, reached a maximum (33 to 41 per cent increase) after 1 to 2 hours, and remained significantly greater than placebo values for 2 to 3 hours. The bronchodilator effect of aerosolized delta9-tetrahydrocannabinol was less than that of isoproterenol after 5 min, but significantly greater than that of isoproterenol after 1 to 3 hours. The magnitude of bronchodilatation after all doses of aerosolized delta9-tetrahydrocannabinol was comparable, but 5 mg of delta9-tetrahydrocannabinol caused a significantly smaller increase in heart rate and level of intoxication than the 20-mg dose. Smoked delta9-tetrahydrocannabinol produced greater cardiac and intoxicating effects than either aerosolized or oral delta9-tetrahydrocannabinol. Side effects of aerosolized delta9-tetrahydrocannabinol included slight cough and/or chest discomfort in 3 of the 11 normal subjects. Aerosolized delta9-tetrahydrocannabinol caused significant bronchodilatation in 3 of 5 asthmatic subjects, but caused moderate to severe bronchoconstriction associated with cough and chest discomfort in the other 2. These findings indicate that aerosolized delat9-tetrahydrocannabinol, although capable of causing significant bronchodilatation with minimal systemic side effects, has a local irritating effect on the airways, which may make it unsuitable for therapeutic use.
D000328:Adult; D000336:Aerosols; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology*; D001980:Bronchi / Q000187:drug effects*; D002490:Central Nervous System / Q000187:drug effects; D002986:Clinical Trials as Topic; D013759:Dronabinol / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007545:Isoproterenol / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D012119:Respiration / Q000187:drug effects
D000336:Aerosols; D013759:Dronabinol; D007545:Isoproterenol