Minoxidil
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From MedlinePlus, U.S. National Library of Medicine
Boxed warning
Minoxidil tablets contain the powerful antihypertensive agent, minoxidil, which may produce serious adverse effects. It can cause pericardial effusion, occasionally progressing to tamponade, and angina pectoris may be exacerbated. Minoxidil should be reserved for hypertensive patients who do not respond adequately to maximum therapeutic doses of a diuretic and two other antihypertensive agents. In experimental animals, minoxidil caused several kinds of myocardial lesions as well as other adverse cardiac effects (see Cardiac Lesions in Animals ).
Minoxidil must be administered under close supervision, usually concomitantly with therapeutic doses of a beta-adrenergic blocking agent to prevent tachycardia and increased myocardial workload. It must also usually be given with a diuretic, frequently one acting in the ascending limb of the loop of Henle, to prevent serious fluid accumulation. Patients with malignant hypertension and those already receiving guanethidine (see WARNINGS ) should be hospitalized when minoxidil is first administered so that they can be monitored to avoid too rapid, or large orthostatic, decreases in blood pressure.
Arteriolar Vasodilator
Dosing in kidney impairment
Concomitant therapy: Diuretic and beta-blocker or other sympathetic nervous system suppressant. Diuretics : Minoxidil must be used in conjunction with a diuretic in patients relying on renal function for maintaining salt and water balance. Diuretics have been used at the following dosages when starting therapy with minoxidil: hydrochlorothiazide (50 mg, b.i.d.) or other thiazides at equi-effective dosage; chlorthalidone (50 mg to 100 mg, once daily); furosemide (40 mg, b.i.d.).
Drug interactions
Check minoxidil against a medication listLabel text (1 paragraph)
4. Drug Interactions See “Interaction with Guanethidine” under WARNINGS.
Contraindications
Minoxidil tablets are contraindicated in pheochromocytoma, because it may stimulate secretion of catecholamines from the tumor through its antihypertensive action. Minoxidil is contraindicated in those patients with a history of hypersensitivity to any of the components of the preparation.
Safety data
Reported adverse events (FAERS)
Liver injury (LiverTox)
ELikelihood score E: Unlikely cause of clinically apparent liver injury.
Minoxidil is an antihypertensive agent that is used largely for patients with severe and refractory hypertension not responding to conventional therapies. Minoxidil is also used topically to treat male pattern baldness. Despite its use for many years, minoxidil has not been convincingly linked to cases of clinically apparent liver injury.
ABCDEA: well known cause; E: unlikely cause. [HD]: high doses only.
Pregnancy and lactation
Pregnancy
6. Pregnancy Teratogenic Effects Pregnancy Category C. Oral administration of minoxidil has been associated with evidence of increased fetal resorption in rabbits, but not rats, when administered at five times the maximum recommended oral antihypertensive human dose. There was no evidence of teratogenic effects in rats and rabbits. Subcutaneous administration of minoxidil to pregnant rats at 80 mg/kg/day was maternally toxic but not teratogenic. Higher subcutaneous doses produced evidence of developmental toxicity. There are no adequate and well controlled studies in pregnant women.
Minoxidil should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Neonatal hypertrichosis has been reported following exposure to minoxidil during pregnancy.
Lactation
8. Nursing Mothers There has been one report of minoxidil excretion in the breast milk of a woman treated with 5 mg oral minoxidil twice daily for hypertension. Because of the potential for adverse effects in nursing infants from minoxidil absorption, minoxidil should not be administered to a nursing woman.
Breastfeeding (LactMed)
Because of the minimal amount of information on this potent agent, use oral minoxidil with caution, particularly when therapy involves a large maternal dosage or breastfeeding a newborn. Maternal topical minoxidil is acceptable once breastfeeding is established. Avoid contact between the infant and skin treated with minoxidil because it can be absorbed by the infant and cause adverse effects such as excessive hair growth.
Supply and cost
Drug shortage status
Recalls (last 24 months)
Therapeutic equivalence (Orange Book)
Price ladder
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