Avoxidil Mechanism of Action

Pharmacotherapeutic group: Dermatological preparations containing minoxidil. ATC code: D11AX01.
Pharmacology: Pharmacodynamics: Mechanism of action: The exact mechanism of action of minoxidil in the treatment of alopecia androgenetica is not known. However, when applied topically, minoxidil has been shown to stimulate hair growth in individuals with alopecia androgenetica.
The onset of hair growth stimulation occurs approximately after 4 or more months of use and is variable among patients. Upon discontinuation of Avoxidil Topical Solution 50mg/ml, new hair growth stops and restoration of pretreatment appearance is expected within 3-4 months.
Pharmacokinetics: Following topical application, minoxidil is poorly absorbed from normal intact skin, with an average of 1.4% (range 0.3-4.5%) of the total applied dose ultimately reaching the systemic circulation.
Therefore, a 1 mL dose of Avoxidil Topical Solution 50mg/ml, delivering 50 mg minoxidil to the skin, would result in absorption of approximately 0.70 mg minoxidil. The effects of concomitant dermal diseases on absorption are unknown.
Serum minoxidil levels resulting from topical administration of minoxidil are governed by the drug's percutaneous absorption rate.
Following cessation of topical dosing of minoxidil approximately 95% of systemically absorbed minoxidil is eliminated within 4 days. The metabolic biotransformation of minoxidil absorbed following topical application has not been fully determined.