Minoxidil

Minoxidil is indicated only in the treatment of hypertension that is symptomatic or associated with target organ damage and is not manageable with maximum therapeutic doses of a diuretic plus two other antihypertensive drugs. At present use in milder degrees of hypertension is not recommended because the benefit-risk relationship in such patients has not been defined.

Minoxidil is available under the following different brand names: Loniten, Minodyl, and Minoxidil HTN.

Dosages of Minoxidil:

Adult and Pediatric Dosage Forms and Strengths

Tablet

• 2.5 mg
• 10 mg

Dosage Considerations – Should be Given as Follows:

Severe or Refractory Hypertension (HTN)

• Adult, Initial: 5mg orally once/day, increase every 3 days as needed
• Adult, Maintenance: 2.5-80 mg/day once/day or every 12 hours; not to exceed 100 mg/day
• Children under 12 years

Children over 12 years

• Initial: 5mg orally once/day, increase every 3 days as needed
• Maintenance: 2.5-80 mg/day once/day or every 12 hours; not to exceed 100 mg/day

Geriatric: 2.5 mg orally once/day; titrate to response gradually

Common side effects of minoxidil include:

• Excessive hair growth
• Abnormal electrocardiogram (ECG)
• Fluid around the heart
• Dizziness
• Drowsiness
• Tiredness
• Temporary swelling (edema), especially during the first few weeks as your body adjusts to the lower blood pressure
• Nausea
• Vomiting
• Breast pain or tenderness

Other side effects of minoxidil include:

• Chest pain (angina)
• Cardiac tamponade
• Fluid and sodium retention
• Low blood pressure (hypotension)
• Pericarditis
• Fast heart rate
• Stevens-Johnson syndrome (rare)
• Hirsutism
• Low white blood cell count (leukopenia) (rare)
• Low platelet count (thrombocytopenia) (rare)
• Toxic epidermal necrolysis

This is not a complete list of side effects and other serious side effects may occur. Call your doctor for information and medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

If your doctor has directed you to use this medication for your condition, your doctor or pharmacist may already be aware of any possible drug interactions or side effects and may be monitoring you for them. Do not start, stop, or change the dosage of this medicine or any medicine before getting further information from your doctor, healthcare provider, or pharmacist first.

• Severe Interactions of minoxidil include:
  • None
• Serious Interactions of minoxidil include:
  • None
• Moderate Interactions of minoxidil include:
  • aldesleukin
  • amifostine
  • avanafil
  • carbidopa
  • dulaglutide
  • epoprostenol
  • fenoldopam
  • hydralazine
  • iloprost
  • levodopa
  • maraviroc
  • nitroglycerin rectal
  • tadalafil
  • teduglutide
  • treprostinil
  • xipamide
• Minoxidil has mild interactions with at least 26 different drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Warnings

• Can precipitate effusion, occasionally progressing to tamponade.
• May exacerbate angina pectoris.
• Reserve for patients who do not respond adequately to maximum therapeutic doses of a diuretic and 2 other antihypertensives.
• In experimental animals, minoxidil caused several kinds of myocardial lesions as well as other adverse cardiac effects.
• Must be administered under close supervision, usually concomitantly with therapeutic doses of a beta-adrenergic blocking agent to prevent tachycardia and increased myocardial workload.
• Usually given with a diuretic (typically loop diuretic) to prevent serious fluid accumulation.
• Patients with malignant hypertension and those already receiving guanethidine should be hospitalized when minoxidil is first administered (monitoring required because of the risk for rapid/large decrease in blood pressure).
• This medication contains minoxidil. Do not take Loniten, Minodyl, or Minoxidil HTN if you are allergic to minoxidil or any ingredients contained in this drug.
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• Hypersensitivity to minoxidil
• Pheochromocytoma

Effects of Drug Abuse

• No information available

Short-Term Effects

• See "What Are Side Effects Associated with Using Minoxidil?"

Long-Term Effects

• See "What Are Side Effects Associated with Using Minoxidil?"

Cautions

• Use with beta-blocker or centrally-acting drug and a diuretic.
• Reserve for severe hypertension refractory to other drugs.
• Pericarditis and pericardial effusion with tamponade reported; observe patients closely for any suggestion of cardiac disorder; perform echocardiographic studies if cardiac disorder suspected; may treat with diuretics, dialysis, pericardiocentesis, or surgery; discontinue therapy if effusion persists.
• In patients with severe blood pressure elevation, too rapid control of blood pressure, especially with intravenous agents, can precipitate fainting, cerebrovascular accidents, heart attack (myocardial infarction), and ischemia of special sense organs with resulting decrease or loss of vision or hearing; patients with compromised circulation or cryoglobulinemia may also suffer ischemic episodes of affected organs.
• Patients with malignant hypertension should have initial treatment with minoxidil carried out in a hospital setting, both to assure that blood pressure is falling and to assure that it is not falling more rapidly than intended.
• Tablets have not been used in patients who have had a myocardial infarction within a preceding month; use caution.
• Neonatal hypertrichosis was reported following exposure to minoxidil during pregnancy.
• May exacerbate heart failure.

Pregnancy and Lactation

• Use minoxidil with caution during pregnancy if the benefits outweigh the risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.
• Minoxidil use during lactation is controversial. Minoxidil is excreted in breast milk. It is not recommended for long-term use if breastfeeding.