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Minoxidil Side Effects

Medically reviewed by Drugs.com. Last updated on Mar 22, 2022.

For the Consumer

Applies to minoxidil: oral tablets

Warning

  • Risk of developing potentially serious cardiac effects.110 b (See Cardiovascular Effects under Cautions.) Pericardial effusion, progressing to tamponade may occur and angina pectoris may be exacerbated.110 b Reserve for hypertensive patients who do not respond to maximum therapeutic doses of a diuretic and 2 other antihypertensive agents.110 b

  • In animal studies, minoxidil caused myocardial lesions and other adverse cardiac effects.110 b

  • Administer under close supervision, usually concomitantly with a β-adrenergic blocking agent (β-blocker) and a diuretic, usually a loop diuretic, to prevent adverse effects.110 b

  • Hospitalize and monitor patients with malignant hypertension or those already receiving concomitant guanethidine therapy to prevent too rapid or severe orthostatic decreases in BP.110 b

Side effects include:

Hypertrichosis, salt and water retention, pericardial effusion, nausea, vomiting.

For Healthcare Professionals

Applies to minoxidil: compounding powder, oral tablet

General

Most patients receiving have experienced a decrease of preexisting adverse medical events attributable to their disease or previous therapy. The most frequently reported side effects were hypertrichosis, tachycardia, pericarditis, and an abnormal ECG.[Ref]

Cardiovascular

Very common (10% or more): ECG abnormal (up to 60%), tachycardia, pericarditis

Common (1% to 10%): Pericardial effusion, tamponade

Frequency not reported: Angina pectoris, hypotension[Ref]

Dermatologic

Very common (10% or more): Hypertrichosis (up to 80%), hair color changed

Rare (less than 0.1%): Stevens-Johnson syndrome, dermatitis bullous, rash

Frequency not reported: Toxic epidermal necrolysis[Ref]

Elongation, thickening, and enhanced pigmentation of fine body hair has been reported in about 80% of patients. This usually develops within 3 to 6 weeks after beginning therapy and is first noticed on the temples, between the eyebrows, between the hairline and the eyebrows, or in the sideburn area of the upper lateral cheek, and eventually extending to the back, arms, legs, and scalp. Upon discontinuation of this drug, new hair growth stops, however, 1 to 6 months may be required for restoration to pretreatment appearance. Endocrine abnormalities have not been found to explain the abnormal hair growth.[Ref]

Gastrointestinal

Common (1% to 10%): Gastrointestinal disorder

Frequency not reported: Nausea/vomiting, gastrointestinal intolerance[Ref]

Hematologic

Rare (less than 0.1%): Leukopenia, thrombocytopenia

Frequency not reported: Hematocrit decreased, hemoglobin decreased, erythrocyte count decreased

Metabolic

Common (1% to 10%): Fluid retention[Ref]

Genitourinary

Uncommon (0.1% to 1%): Breast tenderness[Ref]

Respiratory

Uncommon (0.1% to 1%): Pleural effusion

Other

Common (1% to 10%): Edema

Frequency not reported: Peripheral edema, weight gain, blood creatinine increased, blood urea increased, alkaline phosphatase increased[Ref]

References

1. "Product Information. Loniten (minoxidil)." Pharmacia and Upjohn (2002):

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Cerner Multum, Inc. "Australian Product Information." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.