Table 1.
Summary of Experimental Studies that Examined Exposure to Marijuana and Acute Cardiovascular Changes
| Study year, citation, and design | Study population | Dose of MJ exposure | Outcome examined | Result in study | Risk of bias† |
|---|---|---|---|---|---|
| Klumpers LE, et al. 2012 “Novel Delta (9) THC formulation Namisol (R) has beneficial pharmacokinetics and promising pharmacodynamic effects.” Br J Clin Pharmacol. RCT | 21 healthy MJ users, age 18 to 55, mean age 21.6 | Panel I: 5 mg oral or sublingual THC. Panel II: 6.5 or 8 mg oral THC or matching placebo | 1.Tachycardia |
• Exposure to 5 mg oral THC showed no significant difference in HR (p = 0.9261) compared with 5 mg sublingual THC in pane I. • Exposure to 6.5 and 8 mg THC showed significant increase in HR (p = 0.0019 and p = 0.0014, respectively) compared with placebo control group. |
Low |
| Cooper, et al. 2009 “Comparison of subjective, pharmacokinetic, and physiological effects of marijuana smoked as joints and blunts.” Drug and alcohol dependence. RCT | 24 young healthy current MJ users, age 21 to 45, mean age 25.5 | MJ blunt: 1.8, 3.6% THC or MJ cigarette: 1.8, 3.6% THC or placebo | 1.Tachycardia |
• Subjects randomized to receive placebo, a MJ blunt, or MJ cigarette. • Exposure to highest dose of both joints and blunts MJ showed significant increase in HR (p ≤ 0.05) compared with inactive MJ (placebo). There was no difference in tachycardia between blunts and joints. |
High |
| D’souza, et al. 2008 “Blunted psychotomimetic and amnestic effects of Δ-9-tetrahydrocannabinol in frequent users of cannabis.” Neuropsychopharmacology. RCT | 30 frequent cannabis users and 22 healthy controls, age 18 to 55, mean age 26.9 | 2.5 mg or 5 mg THC per injection or placebo | 1.Tachycardia |
• Subjects randomized to receive placebo, 2.5 or 5 mg THC through injection. • Exposure to cannabis showed increase in HR in a dose-dependent manner (dose: F (1,427) = 65.5, p < 0.0001); dose*time (F (8,427) = 21.1, p < 0.0001) with no significant group differences, even at baseline compared with controls. |
Moderate |
| Mathew, et al. 2003 “Postural syncope after marijuana: a transcranial Doppler study of the hemodynamics.” Pharmacol Biochem Behav. RCT | 29 young healthy experienced MJ users, age 20–38, mean age 25.5 | 3.55% smoke THC or 0.2 mg/ml infusion THC in albumin (4 mg total) or placebo |
1.Increase in pulse rate 2.Decrease in BP 3.CBV |
• Subjects divided to 2 groups (MJ cigarette or placebo) and (THC injection and placebo). • Exposure to MJ showed increase in resting pulse rate (F = 87.46, df = 1,27, p < .001) in both groups with no group differences. • Exposure to MJ showed drop in systolic BP (t = 2.90, df = 27, p < 0.01) • Exposure to MJ showed greater drop in CBV (t = 2.92, df = 27, p < 0.007) in more DZ group. |
Low |
| Chait Perry, et al. 1994 “Acute and residual effects of alcohol and marijuana, alone and in combination, on mood and performance.” Psychopharmacology. RCT | 20 young healthy current MJ users, age 21 to 34, mean age 24.7 | 3.6% THC per cigarette | 1.Tachycardia |
• Subjects grouped as placebo alcohol, low and high alcohol conditions with average of 4.7 ± 0.4, 4.7 ± 0.3, and 5.1 ± 0.4 MJ cigarette exposure, respectively. • Exposure to MJ showed increase in HR with mean (± SE) of 17.1 ± 2.5, 17.8 ± 2.5, and 18.7 ± 2.2 for placebo alcohol, low and high alcohol conditions. It also showed HR increases was moderately correlated to number of MJ cigarette (r = 0.45). |
Moderate |
| Lex, et al. 1984 “Effects of acute marijuana smoking on pulse rate and mood states in women.” Psychopharmacolog. RCT | 28 young female MJ users, age 21 to 36, mean age 26.07 | 1.8% THC per cigarette or placebo | 1.Tachycardia |
• Pulse rate was recorded 30 min prior and at 15, 30, 90, and 180 min post-exposure. • Exposure to MJ showed differences in PR at 15 min (p < 0.01 for both regular and intermittent smokers) and 30 min (p < 0.01 for regular smokers, p < 0.001 for intermittent smokers) compared with placebo. |
High |
| Pihl, et al. 1978 “The effect of marihuana intoxication on blood pressure.” J Clin Psychol. RCT | 48 young male experienced MJ users, age 18 to 35, mean age 23 | Low does MJ: 0.005 g or 0.003 g THC per cigarette, high dose MJ: 0.006 g or 0.0045 g THC per cigarette |
1.Tachycardia 2.Increase/decrease in BP |
• Subjects randomized to receive coltsfoot, placebo, low dose MJ, and high dose MJ. • Exposure to MJ showed highly significant differences in PR (drug*time F = 4.62, df = 1/44, p < 0.01) between the groups. • Exposure to MJ showed no significant differences in SBP and DBP between the groups. However, it showed significant differences between pre-post-exposure and decrease in SBP (F = 5.34, df = 1/44, p < 0.05). |
High |
| Ponto, et al. 2004 “Effect of acute marijuana on cardiovascular function and central nervous system pharmacokinetics of [15O] water: effect in occasional and chronic users.” J Clin Pharmacol. Experimental study | 12 occasional and 12 chronic MJ users, age 20 to 36, mean age 22.1 | 20 mg THC per cigarette or placebo |
1.Tachycardia 2.Increase/decrease in BP 3.Cerebral blood flow |
• Subjects randomized to receive placebo or active MJ cigarette. • Exposure to MJ showed significant relation between change in HR and MJ use status (p < 0.0001) with the repeated-measures ANOVA. • Exposure to MJ showed no difference between MJ use (occasional and chronic) status and change in SBP or DBP. • Exposure to MJ showed no change in global cerebral blood flow (evaluated via PET scans) between MJ and placebo groups. |
High |
| Mathew, et al. 1993 “Depersonalization after marijuana smoking.” Biol Psychiatry. Experimental study | 35 young healthy MJ users, mean age 27.1 | 1.75%, 3.55% THC per cigarette or placebo |
1.Tachycardia 2.Increase/decrease in BP |
• Subjects randomized to receive placebo, 1.75% or 3.55% THC cigarette. • Exposure to MJ showed significant linear association between MJ dose and PR [drug*time interaction (F) = 14.79, p < 0.001]. • Exposure to MJ showed slight but significant linear association between MJ dose and decrease in systolic BP [F = 3.08, p < 0.02]. |
Moderate |
| Mendelson, et al. 1984 “Reinforcing properties of oral Δ 9-tetrahydrocannabinol, smoked marijuana, and nabilone: Influence of previous marijuana use.” Psychopharmacology. *Experimental study | 23 young healthy male MJ users, age 22 to 30, mean age 25.5 | 2 mg oral nabilone or 1 g MJ cigarette (1.83% THC) or 17.5 mg oral THC or placebo | 1.Tachycardia |
• Exposure to MJ showed significant increase in PR (p < 0.01) among intermittent and occasional users following MJ smoking. • Exposure to MJ showed a small but significant increase in PR (p < 0.05) among regular and intermittent users following oral THC administration. However, it showed a greater increase in PR among occasional users (p < 0.01). • Exposure to MJ showed a small but statistically significant elevation in PR (p < 0.05) among all subjects following nabilone administration (no tachycardia observed). |
Moderate |
| Ashton, et al. 1981 “The seed and the soil: effect of dosage, personality and starting state on the response to delta 9 tetrahydrocannabinol in man.” Br J Clin Pharmacol. Experimental study | 32 young healthy MJ users, mean age 23.4 |
Exp1: 2.5 mg or 10 mg THC per cigarette. Exp2: 8 mg THC per cigarette or placebo |
1.Tachycardia |
• Exposure to 2.5 mg THC showed 14.5% increase in HR 1 min after smoking compared with the mean pre-smoking rate in experiment 1. It also showed 34.8% increase in HR 15 min after smoking of 10 mg THC. • Exposure to 8 mg THC showed increase in HR by mean rise of 12.6 bpm 13 min after smoking compared with placebo. |
High |
| Miller, et al. 1977 “Marijuana: Dose-response effects on pulse rate, subjective estimates of potency, pleasantness, and recognition memory.” Pharmacology. Experimental study | 32 healthy male moderate MJ users, age 21 to 28 | 5, 10, 15 mg THC per cigarette or placebo | 1.Tachycardia |
• Exposure to MJ showed linear association between MJ dose (F = 4.97, df = 3, 28; p < 0.007), time effect (F-43.37, df = 3.84, p < 0.0001) and dose*time interaction (F = 8.03, df = 9.84, p < 0.0001). • Exposure to MJ showed increase in PR with dose up to 10 mg with mild reversal at 15 mg dose. |
Moderate |
| Bernstein, et al. 1976 “Medical implications of marijuana use.” Am J Drug Alcohol Abuse. Experimental study | 27 young healthy male MJ users, mean age 23.4 | 2.1% THC per cigarette |
1.Tachycardia 2.Increase/decrease in BP |
•Exposure to MJ showed increase in PR following MJ smoking. It also showed tachycardia was more prominent when the pulse was counted with the subject in the standing position following MJ smoking. • No significant association between MJ smoking and change in BP. |
High |
| Steadward, et al. 1975 “The effects of smoking marihuana on physical performance.” Med Sci Sports. Experimental study | 20 young healthy male MJ users, age 21 to 27, mean age 23.1 | 18.2 mg THC per cigarette or 1.4 mg placebo |
1.Tachycardia 2.Increase in BP |
• Subjects randomized to receive placebo or active MJ cigarette. • Exposure to MJ showed a significant increase in HR (p < 0.05) from control to MJ and from placebo to MJ. • Exposure to MJ showed a significant increase in SBP and DBP (p < 0.05) compared with controls and placebo. |
High |
BP, blood pressure; DBP, diastolic blood pressure; SBP, systolic blood pressure; HR, heart rate; MG, milligram; MJ, marijuana; PR, pulse rate; RCT, randomized control trial; RR, relative risk; THC, tetrahydrocannabinol; CBV, cerebral blood velocity; ANOVA, analysis of variance
*All studies examined the plant form of MJ except *study which also examined the synthetic form
†We used the Cochrane Risk of Bias Tool for Clinical Trials, and NIH Quality Assessment Tool for Controlled Intervention Studies to assess risk of bias (ROB)