Role of oral minoxidil in the treatment of androgenetic alopecia

Patterned hair loss is the most common cause of alopecia, typically presenting with progressive thinning, miniaturization, and loss of hair at classical topography depending on the sex of the patient. In the 1970s, Minoxidil was used to treat severe refractory hypertension due to its vasodilator properties. It became popular after its coincidental finding on the promotion of hair growth and stimulation of new hair production. In 1988, the Food and Drug Administration approved topical minoxidil (TM) 2% for the treatment of male androgenetic alopecia and in 1992, for female pattern hair loss. It is also used as an off-label treatment for other hair loss conditions such as telogen effluvium and alopecia areata. However, there are frequent reports of TM-induced contact dermatitis and its reversible effect, which has reduced compliance in the patients and resulted in a poor outcome. Hence, they have studied using low-dose oral minoxidil (LDOM), which showed good efficacy and safety profile in the treatment of patterned hair loss along with avoidance of high-risk adverse cardiac effects that resulted due to doses used for hypertension. The added advantages of LDOM over topical formulation are good compliance, cost savings, effective in people with low hair follicle sulfotransferase activity, and the possibility of cotherapy with other topical or oral medications.