Cigarettes of marijuana containing 5, 10 and 15 mg of Δ 9 THC, were compared to d amphetamine tablets for their effects on some physiological variables. Half the sample of 12 young male volunteers received active marijuana with a d amphetamine placebo; the other half had the opposite combination. After initial measurement the tablets were administered 1.5 hr before marijuana smoking and 2 hr before response measurement. The dose increment with both drugs produced a significant rise in heart rate (mainly with Δ 9 THC 15 mg). A clear increase of systolic blood pressure was found to be dose related with both substances while respiration rate was not. The only significant differences between marijuana and d amphetamine were shown in the patellar reflex variables: the movement amplitude is greater during the first phase of leg extension and the duration of this phase and that of the next phase (return to initial position) are shorter with marijuana, while leg oscillations are more numerous with d amphetamine. With 5 mg of the latter, time variables as well as EMG suggest, for the same reflex, a predominant stimulation of agonist muscles and, with the higher doses, an approximately equal and simultaneous stimulation of both agonists and antagonists. The marijuana dose increment effects are smaller but seem to be somewhat similar. A significant dose related diminution of performance was found with amphetamine on both the simple reaction time to a visual stimulus and the duration of the simple following movement. Only the energy required for the latter movement was significantly increased by the marijuana dose increment.

Additional Metadata
Journal Toxicomanies
Gagnon, M.A, & Elie, R. (R.). (1973). Marihuana and dexamphetamine: dose and effect relationship on some neurophysiologic and cardiorespiratory variables in man RELATIONS DOSE EFFET DE LA MARIJUANA ET DE LA DEXTROAMPHETAMINE SUR DES VARIABLES NEUROPHYSIOLOGIQUES ET CARDIORESPIRATOIRES CHEZ L'HOMME. Toxicomanies, 6(4), 305–331.