Ma Huang and Captopril: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Captopril
Ma Huang
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Reduced effectiveness of angiotensin converting enzyme inhibitors
Interaction Deep Dive
Theoretically, Ma Huang (ephedra) may decrease the effectiveness of antihypertensive medications. Ma huang had variable effects on blood pressure in normotensive subjects1, and may have caused an acute hypertensive response in a patient ingesting an herbal preparation suspected of containing Ma huang 2. Ma huang (ephedra) is a natural source of ephedrine and pseudoephedrine 1. Ma huang contains 0.5 to 2.5% of ephedra alkaloids. Ephedrine is the dominant alkaloid, comprising 30% to 90% of the total ephedra alkaloid content, depending on growing conditions 3. Pseudoephedrine has been recognized as generally safe, but ephedrine should be avoided by patients with hypertension 4. Patients who are sensitive to either ephedrine or pseudoephedrine, or who have pheochromocytoma should avoid products containing Ma huang.
Why it happens (mechanism)
Antagonistic effect through sympathomimetic activity of ephedrine and pseudoephedrine in Ma huang
Literature reports
2 reports — tap to read
a) Variable effects on blood pressure were found in 12 normotensive patients administered 4 capsules of ma huang (containing ephedrine 19.4 mg and pseudoephedrine 4.9 mg per dose) with breakfast, followed with another 4 capsules nine hours later at the evening meal. Four subjects experienced a significant increase in systolic blood pressure three hours post ingestion, whereas two individuals experienced a decrease in the diastolic blood pressure. Six (50%) patients experienced a significant increase in the mean 12-hour heart rate from 81 to 94 beats per minute (bpm), 79 to 84 bpm, 87 to 97 bpm, 77 to 83 bpm, 69 to 74 bpm, and 77 to 84 bpm (p less than 0.05 for all) 1.
b) A 21-year-old man presented to the emergency department with hypertension following ingestion of one glass of alcohol, one marijuana cigarette, and four capsules of "herbal ecstacy" supposedly containing ginseng, kola nut, and nutmeg (time elapsed: 90 minutes). His initial blood pressure taken by paramedics was 220/110 mmHg and was 190/116 mmHg upon reaching the emergency department, with accompanying ventricular dysrhythmias. His symptoms resolved within 9 hours following treatment with lidocaine and sodium nitroprusside. The urine screen was positive for ephedrine or pseudoephedrine, cannabinoid metabolites, and traces of opiate and caffeine. The authors attribute the patient's condition to the ephedrine content of the herbal preparation. Since all of the product had been consumed, the herbal product was not assayed to determine its relative contents of ephedrine and caffeine 2.
Common questions
Can I take Ma Huang and Captopril together?
Reduced effectiveness of angiotensin converting enzyme inhibitors Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ma Huang and Captopril interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Ma Huang or Captopril need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (4)
- White LM, Gardner SF, & Gurley BJ: Pharmacokinetics and cardiovascular effects of Ma-Huang (ephedra sinica) in normotensive adults. J Clin Pharmacol 1997; 37:116-122.
- Zahn KA, Li RL, & Purssel RA: Cardiovascular toxicity after ingestion of "herbal ecstasy.". J Emerg Med 1999; 17:289-291.
- Blumenthal M & King P: Ma huang: ancient herb, modern medicine, regulatory dilemma. Herbalgram 1995; 34:22-26, 43, 56-57.
- Chua SS & Benrimoj SI: Non-prescription sympathomimetic agents and hypertension. Med Toxicol Adverse Drug Exp 1988; 3:387-417. PubMed
Keep reading about Captopril
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