Does cannabis affect blood pressure medication?

Yes. Cannabis interacts with blood pressure medications through two mechanisms. First, THC produces a biphasic cardiovascular effect — initial tachycardia followed by vasodilation and potential hypotension. Combined with antihypertensive medications, this can produce additive blood pressure lowering beyond the intended therapeutic effect. Second, CBD inhibits CYP3A4 and CYP2D6 — enzymes that metabolize several classes of blood pressure medications including calcium channel blockers (verapamil, diltiazem) and beta-blockers (metoprolol). This raises these drug levels in the bloodstream.

Can you smoke weed while taking lisinopril?

Cannabis and lisinopril (an ACE inhibitor) can produce additive blood pressure lowering through pharmacodynamic interaction. THC causes vasodilation and can lower blood pressure — which, when combined with lisinopril's antihypertensive effect, may produce blood pressure that drops further than intended. The pharmacokinetic interaction is less significant for lisinopril specifically, as it is not primarily CYP-metabolized. Patients on lisinopril who use cannabis should monitor for symptoms of hypotension: dizziness, lightheadedness on standing, and fainting. Prescriber disclosure is recommended.

Does cannabis raise or lower blood pressure?

The blood pressure effect of THC is biphasic and dependent on dose, product, and individual factors. Acutely, THC typically increases heart rate (tachycardia) and may transiently raise blood pressure. This is followed by vasodilation — blood vessel widening — which can lower blood pressure, sometimes significantly. In chronic users, tolerance to the tachycardia effect develops. For people on antihypertensive medications, the concern is this vasodilatory/hypotensive phase combining with their medication's blood pressure-lowering effect, producing excessive blood pressure lowering. CBD at higher doses also has some blood pressure-lowering properties. The net effect varies by product, dose, route, and individual.

Cannabis & Blood Pressure Medications: Additive Hypotension, CYP3A4, Beta-Blockers

Mechanism 1: THC's Cardiovascular Effects

Pharmacodynamic Interaction

THC produces a well-characterized biphasic cardiovascular response that is directly relevant to antihypertensive therapy. Benowitz & Jones, 1975

Phase 1: Tachycardia

Immediately after THC use, heart rate typically increases. This is mediated by sympathetic nervous system activation and endocannabinoid receptor signaling. In patients on beta-blockers (metoprolol, atenolol, carvedilol) — which are prescribed precisely to control heart rate — this THC-induced tachycardia may partially counteract the rate-controlling effect of the medication. The clinical result is less predictable heart rate management.

Phase 2: Vasodilation and Hypotension

THC causes peripheral vasodilation — widening of blood vessels — which reduces blood pressure. When this vasodilatory effect combines with antihypertensive medications already lowering blood pressure, blood pressure may drop lower than the medication alone would produce. The clinical risk is orthostatic hypotension — blood pressure dropping sharply when standing — which causes dizziness, lightheadedness, and falls. NIH NCCIH

Mechanism 2: CYP Enzyme Inhibition

Pharmacokinetic Interaction

CBD and THC inhibit CYP3A4 and CBD additionally inhibits CYP2D6 — enzymes that metabolize several blood pressure medication classes. The clinical consequence is elevated blood pressure drug levels, compounding the hypotensive concern. FDA Epidiolex PI Stout & Cimino, 2014

Drug Class	Examples	Relevant Enzyme	Interaction Notes
Calcium Channel Blockers (non-DHP)	Verapamil (Calan), Diltiazem (Cardizem)	CYP3A4 (primary)	⚠️ Caution — CBD/THC inhibit CYP3A4; verapamil and diltiazem levels may rise significantly. Both drugs already have narrow use windows due to cardiac effects.
Calcium Channel Blockers (DHP)	Amlodipine (Norvasc), Nifedipine	CYP3A4 (primary)	🔵 Moderate — CYP3A4 substrate; less cardiac conduction concern than verapamil/diltiazem, but plasma level elevation still possible.
Beta-Blockers	Metoprolol (Toprol), Carvedilol (Coreg)	CYP2D6 (primary for metoprolol/carvedilol)	🔵 Moderate — CBD inhibits CYP2D6; may raise metoprolol levels. THC's tachycardia counteracts rate control. Two-pathway concern.
Beta-Blockers	Atenolol (Tenormin)	Minimal CYP (renal elimination)	✓ Lower PK Risk — atenolol is not significantly CYP-metabolized; pharmacokinetic interaction lower. THC cardiovascular effects still relevant.
ARBs (Angiotensin Receptor Blockers)	Losartan (Cozaar)	CYP2C9 (losartan active metabolite)	🔵 Moderate — CBD inhibits CYP2C9; may affect losartan conversion to active form. Additive hypotension also applies.
ARBs	Valsartan (Diovan), Olmesartan	Minimal CYP; largely renal	✓ Lower PK Risk — minimal CYP metabolism; pharmacokinetic interaction lower. Additive hypotension still applies.
ACE Inhibitors	Lisinopril, Ramipril, Enalapril	Minimal CYP (renal/hydrolysis)	✓ Lower PK Risk — ACE inhibitors are not significantly CYP-metabolized. Primary concern is additive pharmacodynamic hypotension from THC vasodilation.

Symptoms of Concern: Orthostatic Hypotension

Clinical Warning Signs

The most clinically actionable risk for patients on blood pressure medications who use cannabis is orthostatic hypotension — a significant drop in blood pressure upon standing. This can cause:

Sudden dizziness or lightheadedness when rising from sitting or lying down
Visual darkening or graying out briefly when standing
Near-fainting or fainting (syncope) — particularly dangerous in older adults
Unexplained falls — especially significant in adults over 60
Feeling of weakness or "rubber legs" after standing

Practical Risk Reduction

If cannabis use while on antihypertensives is continued after prescriber discussion: rise slowly from sitting or lying positions, pause before walking, avoid cannabis use in hot environments (which adds additional vasodilation), and avoid combining cannabis with alcohol (further additive hypotension). These precautions reduce orthostatic hypotension risk but do not eliminate it.

Frequently Asked Questions

Common Queries

Can cannabis raise my blood pressure dangerously? ▼

The acute tachycardia phase of THC can transiently raise blood pressure immediately after use — primarily through increased heart rate and sympathetic activation. For most people on stable antihypertensive therapy, the subsequent vasodilatory phase counteracts this. However, in patients with cardiovascular disease, the acute tachycardia phase may itself carry risk — particularly in those with coronary artery disease where rapid heart rate increases myocardial oxygen demand. This is a cardiovascular, not a blood pressure medication interaction concern specifically, but is worth discussing with a cardiologist or prescriber if relevant.

Does CBD lower blood pressure? ▼

Some research, including a small clinical study, has found that single-dose CBD administration modestly reduced blood pressure in healthy subjects. Jadoon KA et al., JCI Insight, 2017 (note: this study used pharmaceutical-grade CBD under controlled conditions and is preliminary). CBD's blood pressure-lowering effect, if clinically real, represents an additive pharmacodynamic concern when combined with antihypertensive medications — adding to the THC vasodilation concern. CBD at consumer product doses and the CBD in full-spectrum products may not produce equivalent effects to controlled study conditions, but the directional concern applies. Prescriber awareness of CBD use is warranted for anyone on antihypertensives.

I take metoprolol for my heart rate. Does cannabis affect it? ▼

Metoprolol (Toprol) is metabolized by CYP2D6 — an enzyme that CBD inhibits. This means CBD use can raise metoprolol plasma levels beyond the intended dose. Elevated metoprolol levels may cause excessive heart rate slowing (bradycardia), fatigue, and blood pressure lowering beyond the prescribed effect. Additionally, THC's acute tachycardia works against metoprolol's rate-controlling purpose — the two have opposing pharmacodynamic effects on heart rate. The combination creates a complex, unpredictable heart rate profile. Patients on metoprolol for rate control who use cannabis should disclose this to their cardiologist or prescriber for individual evaluation.

Is cannabis safer to use with lisinopril than with amlodipine? ▼

From a pharmacokinetic standpoint, yes — lisinopril is not significantly CYP-metabolized, so CBD's CYP enzyme inhibition does not raise lisinopril levels the way it may raise amlodipine levels. However, both drugs are subject to additive pharmacodynamic hypotension from THC's vasodilatory effects. The practical clinical concern — dizziness, lightheadedness, and falls from blood pressure dropping too low after cannabis use — applies to both. The specific statin-style "one is safer than the other" distinction based on enzyme metabolism does not fully apply here because the dominant concern is pharmacodynamic, not pharmacokinetic, for ACE inhibitors like lisinopril.

👨‍⚕️ Clinical Reviewer

Sanford A. Orloff, RPh (ret.)

Registered Pharmacist · 40+ Years Clinical Experience · NPI: 1518289974
View credentials → · Verify NPI →

📚

Primary Sources

Benowitz NL, Jones RT. "Cardiovascular effects of prolonged delta-9-tetrahydrocannabinol ingestion." Clinical Pharmacology & Therapeutics. 1975 Sep;18(3):287-97. PMID: 1157433. Documents THC biphasic cardiovascular effects including tachycardia and vasodilation.
https://doi.org/10.1002/cpt1975183287
FDA. Epidiolex (cannabidiol) Prescribing Information. NDA 210365. CYP2D6 and CYP3A4 inhibition by CBD; relevant to calcium channel blockers and beta-blockers.
https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/210365s006lbl.pdf
Stout SM, Cimino NM. "Exogenous cannabinoids as substrates, inhibitors, and inducers of human drug metabolizing enzymes: a systematic review." Drug Metabolism Reviews. 2014;46(1):86-95. PMID: 24160757.
https://doi.org/10.3109/03602532.2013.849268
NIH NCCIH. "Cannabis (Marijuana) and Cannabinoids: What You Need To Know." Updated December 2021. Cardiovascular effects and antihypertensive interaction concerns.
https://www.nccih.nih.gov/health/cannabis-marijuana-and-cannabinoids-what-you-need-to-know
NIH MedlinePlus. Metoprolol; Amlodipine; Lisinopril; Verapamil Drug Information. National Library of Medicine. Metabolism and interaction documentation.
https://medlineplus.gov/druginformation.html