Effects of marihuana‐dextroamphetamine combination

Abstract

Under a double blind, randomized, complete block design, subjects were given either placebo and 10 mg/70 kg dextroamphetamine sulfate (A) orally followed 1 1/2 hr later by a marihuana cigarette (M) prepared to deliver 50 mug/kg delta-9-tetrahydrocannabinol (THC). Statistical analyses suggested that heart rate and blood pressure increased in an additive manner when both drugs were given. Electrocardiogram changes, when present, were nonspecific in character and appeared to be associated with marihuana. In a second study, psychomotor performance was evaluated by a similar design using doses of 10 mg/70 kg of A and M prepared to deliver 25 mug/kg THC. Impairment was related to smoking of M, and no difference could be distinguished between M alone and M-A combination. Subjective evaluation, as measured by the modified Cornell Medical Index (CMI) demonstrated only additive effects for the combination.

Impairment related to blood amphetamine and/or methamphetamine concentrations in suspected drugged drivers

“…Such doses give rise to a C max about 0.10-0.15 mg/l (Silber et al, 2005a). In most of these studies no relationship between impairment and blood amphetamines concentrations or the doses of amphetamines taken has been found (Angrist et al, 1987;Asghar et al, 2003;Brauer et al, 1996;Evans et al, 1976;Heishman et al, 1998;Perez-Reyes et al, 1992;Pickworth et al, 1997;Silber et al, 2005b;Slattum et al, 1996). In real-life settings doses taken are commonly much higher (50-300 mg or more), and are often taken intravenously in binges.…”

Strategies for Research on the Interactions of Drugs of Abuse: NIDA Research Monograph 68

“…Similar additive effects were seen in subjects given 10 mg/70 Kg doses of dextroamphetamine and 50 ug/Kg doses of THC by smoking. In this case, dextroamphetamine did not counter the adverse effects of marijuana on motor performance (Evans et al 1974). Instances of combined use of amphetamines and marijuana are infrequent in social practice.…”

Interactions between dopamine transporter and cannabinoid receptor ligands in rhesus monkeys

“…In the same study, bupropion enhanced marijuana withdrawal. However, qualitatively different results have been reported for cocaine and amphetamine, with marijuana producing additive subjective and cardiovascular effects with amphetamine (Evans et al 1976) or cocaine (Foltin et al 1987; 1993). In another study, haloperidol enhanced some of the effects of Δ 9 -THC on performance in humans (D’Souza et al 2008), consistent with the current results.…”

“…When cannabinoids and dopaminergic ligands share effects, their combined effects are generally additive. Marijuana, cocaine, and amphetamine shared some physiological and behavioral effects in humans and, when combined, marijuana had additive effects with cocaine and amphetamine (Zalcman et al 1973; Evans et al 1976; Foltin et al 1987; 1993). Additivity in rats was reported for the effects of Δ 9 -THC and amphetamine on ingestive behavior and body weight (Hattendorf et al 1977), for the effects of dopamine receptor agonists and a cannabinoid antagonist (rimonabant) on motor activity (Compton et al 1996; Giuffrida et al 1999; Masserano et al 1999), and for the cataleptic effects of a cannabinoid agonist and dopamine antagonist (Anderson et al 1996).…”