Doxazosin and Yohimbine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Doxazosin
Yohimbine
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 alpha-1 adrenergic blocker effectiveness
Interaction Deep Dive
Theoretically, yohimbine may directly counteract the hypotensive effect of alpha-1 adrenergic blockers, resulting in inadequate blood pressure control in hypertensive patients. Yohimbine increased blood pressure in hypertensive and normotensive patients in several studies12345. Yohimbine is believed to increase norepinephrine release by at least one of three mechanisms: direct stimulation of sympathetic outflow from the brain; blockade of inhibitory alpha-2 adrenergic receptors on sympathetic nerve endings; blockade of alpha-2 adrenergic receptors on vascular smooth muscle with vasodilation eliciting reflexive increases in sympathetic outflow 4.
Why it happens (mechanism)
Increased norepinephrine release by yohimbine
Literature reports
5 reports — tap to read
a) Yohimbine 10 mg taken orally induced a significant increase in diastolic blood pressure after 10 minutes of upright posture in hypertensive patients only in a placebo-controlled study of 25 healthy volunteers and 29 sex- and age-matched untreated mild to moderate hypertensive patients. Yohimbine produced a significant increase in plasma norepinephrine levels in both groups. Dopamine levels were significantly increased only in normotensive subjects after yohimbine administration (exact values not provided) 1.
b) Yohimbine 21.6 mg taken orally stimulated norepinephrine release, resulting in a pressor response in a study of 25 adult patients with uncomplicated essential hypertension. The systolic and diastolic blood pressures at baseline were 144 +/- 4 and 83 +/- 3 mmHg, respectively. Patients discontinued any antihypertensive medication 2 weeks prior to the study. At one hour after yohimbine administration, systolic pressure increased to 150 +/- 5 mmHg (p less than 0.01) and diastolic pressure increased to 86 +/- 3 mmHg (p less than 0.01). Heart rate was not significantly changed by yohimbine. Norepinephrine levels increased from 293 +/- 29 picograms (pg)/mL (1.732 +/- 0.171 nanomol (nmol)/L) at baseline to 486 +/- 67 pg/mL (2.873 +/- 0.396 nmol/L) (p less than 0.001) one hour after yohimbine administration 2.
c) Yohimbine 0.2 mg/kg taken orally increased plasma concentrations of noradrenaline 67% in 9 hypertensive patients and 178% in 6 normotensive patients. Blood pressure increased significantly in response to yohimbine in hypertensive but not normotensive subjects. Patients did not take medications acting on blood pressure or the sympathetic nervous system; hypertensive patients averaged 68 years, normotensive patients averaged 63 years 3.
d) Yohimbine administered intravenously increased mean arterial pressure, norepinephrine, and epinephrine levels in all patients (p less than 0.001) in a study of 19 hypertensive patients and 19 normotensive patients. Yohimbine was administered as a 0.125 mg/kg IV bolus followed by 0.001 mg/kg/minute infusion for 15 minutes. Patients discontinued all medications 2 weeks prior to the study. Hypertensive patients averaged 35 years; normotensive patients averaged 30 years. Mean arterial pressure increased from 106 mmHg to 127 mmHg in the hypertensive group and from 88 mmHg to 101 mmHg in the normotensive group; in all patients, the increase was significant versus baseline 4.
e) In a randomized, double-blind study of 17 male volunteers, oral yohimbine 40 mg increased the rate of appearance of norepinephrine into the plasma (p less than 0.005) without a reduction in norepinephrine clearance. Plasma epinephrine was significantly increased. Diastolic blood pressure increased (p less than 0.01) as well as mean arterial blood pressure and pulse (p less than 0.025) 5.
Common questions
Can I take Doxazosin and Yohimbine together?
Reduced alpha-1 adrenergic blocker effectiveness Always confirm with your pharmacist or prescriber before making any change.
How serious is the Doxazosin and Yohimbine 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Doxazosin or Yohimbine 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 (5)
- Musso NR, Vergassaol C, Pjende A, et al: Yohimbine effects on blood pressure and plasma catecholamines in human hypertension. Am J Hypertens 1995; 8(6):565-571. PubMed
- Grossman E, Rosenthal T, Peleg E, et al: Oral yohimbine increased blood pressure and sympathetic nervous outflow in hypertensive patients. J Cardiovasc Pharmacol 1993; 22(1):22-26.
- Damase-Michel C, Tran MA, Llau ME, et al: The effect of yohimbine on sympathetic responsiveness in essential hypertension. Eur J Clin Pharmacol 1993; 44(2):199-201. PubMed
- Goldstein DS, Grossman E, Listwak S, et al: Sympathetic reactivity during a yohimbine challenge test in essential hypertension. Hypertension 1991; 18(Suppl 5):III40-48. DOI
- Murburg MM, Villacres EC, Ko GN, et al: Effects of yohimbine on human sympathetic nervous system function. J Clin Endocrinol Metab 1991; 73(4):861-865. PubMed
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