Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2018 Jan 31;11(1):13.
doi: 10.3390/ph11010013.

A Systematic Review and Meta-Analysis of the In Vivo Haemodynamic Effects of Δ⁸-Tetrahydrocannabinol

Salahaden R Sultan  1   2 , Sophie A Millar  3 , Saoirse E O'Sullivan  4 , Timothy J England  5
Affiliations
Review

A Systematic Review and Meta-Analysis of the In Vivo Haemodynamic Effects of Δ⁸-Tetrahydrocannabinol

Salahaden R Sultan et al. Pharmaceuticals (Basel). .

Abstract

∆⁸-Tetrahydrocannabinol (THC) has complex effects on the cardiovascular system. We aimed to systematically review studies of THC and haemodynamic alterations. PubMed, Medline, and EMBASE were searched for relevant studies. Changes in blood pressure (BP), heart rate (HR), and blood flow (BF) were analysed using the Cochrane Review Manager Software. Thirty-one studies met the eligibility criteria. Fourteen publications assessed BP (number, n = 541), 22 HR (n = 567), and 3 BF (n = 45). Acute THC dosing reduced BP and HR in anaesthetised animals (BP, mean difference (MD) -19.7 mmHg, p < 0.00001; HR, MD -53.49 bpm, p < 0.00001), conscious animals (BP, MD -12.3 mmHg, p = 0.0007; HR, MD -30.05 bpm, p < 0.00001), and animal models of stress or hypertension (BP, MD -61.37 mmHg, p = 0.03) and increased cerebral BF in murine stroke models (MD 32.35%, p < 0.00001). Chronic dosing increased BF in large arteries in anaesthetised animals (MD 21.95 mL/min, p = 0.05) and reduced BP in models of stress or hypertension (MD -22.09 mmHg, p < 0.00001). In humans, acute administration increased HR (MD 8.16 bpm, p < 0.00001). THC acts differently according to species and experimental conditions, causing bradycardia, hypotension and increased BF in animals; and causing increased HR in humans. Data is limited, and further studies assessing THC-induced haemodynamic changes in humans should be considered.

Keywords: THC; blood flow; blood pressure; cardiovascular system; heart rate; ∆9-Tetrahydrocannabinol.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure A1
Figure A1
Funnel plots for each outcome evaluating the publication bias. The standard error (SE) of the mean difference (MD) in haemodynamics (MD, y axis) for each study is plotted against its effect size (horizontal axis). There was significant bias in conscious animals (B) (p = 0.001), animal models of stress or hypertension (C) (p = 0.001), and humans (D) (p < 0.0001). No significant bias in anaesthetised animals (A).
Figure 1
Figure 1
Flow chart for study retrieval and selection.
Figure 2
Figure 2
Changes in (A) BP and (B) HR induced by acute THC dosing in anaesthetised animals.
Figure 2
Figure 2
Changes in (A) BP and (B) HR induced by acute THC dosing in anaesthetised animals.
Figure 3
Figure 3
Changes in (A) blood pressure, (B) heart rate, and (C) blood flow (BF) induced by chronic THC dosing in anaesthetised animals.
Figure 4
Figure 4
Changes in (A) BP, (B) HR, and (C) blood flow induced by acute THC dosing in conscious animals.
Figure 4
Figure 4
Changes in (A) BP, (B) HR, and (C) blood flow induced by acute THC dosing in conscious animals.
Figure 5
Figure 5
Changes in BP induced by (A) acute and (B) chronic THC dosing in animal models of stress or hypertension.
Figure 5
Figure 5
Changes in BP induced by (A) acute and (B) chronic THC dosing in animal models of stress or hypertension.
Figure 6
Figure 6
Changes in HR induced by acute THC dosing in humans.
Figure 7
Figure 7
The effect of different THC doses on haemodynamic responses in vivo. The mean difference (MD) in animals’ blood pressure (BP, (A)), animals’ heart rate (HR, (B)), or heart rate (in humans only) (p = 0.01) (HR, (C)) is plotted against the log dose (mg) for each study. Error bars represent 95% confidence intervals (CI). Near-significant and significant dose-dependent effects on the blood pressure in animals (p = 0.07) and on the HR in humans (p = 0.01).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Gaoni Y., Mechoulam R. Isolation, Structure, and Partial Synthesis of an Active Constituent of Hashish. J. Am. Chem. Soc. 1964;86:1646–1647. doi: 10.1021/ja01062a046. - DOI
    1. Pertwee R.G. Pharmacological actions of cannabinoids. Handb. Exp. Pharmacol. 2005;20:1–51. - PubMed
    1. Ryberg E., Larsson N., Sjögren S., Hjorth S., Hermansson N.O., Leonova J., Elebring T., Nilsson K., Drmota T., Greasley P.J. The orphan receptor GPR55 is a novel cannabinoid receptor. Br. J. Pharmacol. 2007;152:1092–1101. doi: 10.1038/sj.bjp.0707460. - DOI - PMC - PubMed
    1. McHugh D., Page J., Dunn E., Bradshaw H.B. Delta(9) -Tetrahydrocannabinol and N-arachidonyl glycine are full agonists at GPR18 receptors and induce migration in human endometrial HEC-1B cells. Br. J. Pharmacol. 2012;165:2414–2424. doi: 10.1111/j.1476-5381.2011.01497.x. - DOI - PMC - PubMed
    1. Ben Amar M. Cannabinoids in medicine: A review of their therapeutic potential. J. Ethnopharmacol. 2006;105:1–25. doi: 10.1016/j.jep.2006.02.001. - DOI - PubMed

LinkOut - more resources