Drug Guide

Generic Name

Minoxidil

Brand Names Loniten, Rogaine (for Men), Rogaine (for Women), Rogaine Extra Strength (for Men), Men's Rogaine, Women's Rogaine, Minodyl, Minoxidil (for Men), Minoxidil (for Women), Minoxidil Extra Strength (for Men), Theroxidil

Classification

Therapeutic: Antihypertensive (topical for hair growth)

Pharmacological: Vasodilator

FDA Approved Indications

Hypertension (oral, off-label)
Androgenetic alopecia (topical)

Mechanism of Action

Minoxidil opens potassium channels, causing hyperpolarization of cell membranes, leading to vasodilation and increased blood flow. When used topically, it promotes hair follicle proliferation and prolongs the anagen phase of hair growth.

Dosage and Administration

Adult: Topical: 1 mL applied to affected area twice daily.

Pediatric: Not approved for pediatric use.

Geriatric: No specific dosage adjustment needed based on age.

Renal Impairment: Use with caution, as systemic absorption may occur.

Hepatic Impairment: No specific dosage adjustment; systemic effects are minimal.

Pharmacokinetics

Absorption: Minimal when applied topically; systemic absorption occurs with topical use.

Distribution: Bound to plasma proteins.

Metabolism: Metabolized in the liver to inactive compounds.

Excretion: Excreted mainly in urine.

Half Life: Approximately 22 hours (systemic absorption).

Contraindications

Hypersensitivity to minoxidil or any component.
Sudden hair loss or scalp irritation.

Precautions

Use with caution in patients with cardiovascular disease, particularly where systemic absorption could cause hypotension.

Adverse Reactions - Common

Scalp irritation, itching, redness (Common)
Unwanted facial/body hair (topical use) (Uncommon)

Adverse Reactions - Serious

Rapid heartbeat, dizziness, chest pain (systemic exposure) (Rare)
Hypotension, edema (systemic exposure) (Rare)

Drug-Drug Interactions

Other vasodilators
CNS depressants

Drug-Food Interactions

None significant

Drug-Herb Interactions

Potential interactions with other blood pressure lowering herbs such as ginseng

Nursing Implications

Assessment: Monitor blood pressure, scalp condition, and for adverse reactions.

Diagnoses:

Risk of falls related to hypotension
Impaired skin integrity related to scalp reactions

Implementation: Educate on proper topical application, hygiene, and side effect monitoring.

Evaluation: Assess effectiveness in hair growth, side effects, and blood pressure changes.

Patient/Family Teaching

Apply only as directed on the scalp.
Wash hands thoroughly after application.
Report signs of unwanted hair growth, dizziness, or scalp irritation.
Avoid applying to broken or irritated scalp.

Special Considerations

Black Box Warnings:

Limited data on systemic absorption; systemic side effects possible, especially with overuse.

Genetic Factors: Response may vary based on genetic predispositions.

Lab Test Interference: None reported.

Overdose Management

Signs/Symptoms: Dizziness, lightheadedness, rapid heartbeat, areas of unwanted hair growth.

Treatment: Discontinue use, monitor vital signs, provide supportive care, and administer vasodilators or medications for hypertension if systemic effects occur.

Storage and Handling

Storage: Store at room temperature, away from heat and humidity.

Stability: Stable for 2-3 years when stored properly.