Minoxidil

Minoxidil is a medication used for the treatment of male-pattern hair loss. It is an antihypertensive vasodilator. It is available as a generic medication and over the counter. Minoxidil is a medication used for the treatment of male-pattern hair loss. It is an antihypertensive vasodilator. It is available as a generic medication and over the counter. Minoxidil, applied topically, is widely used for the treatment of hair loss. It is effective in helping promote hair growth in people with androgenic alopecia regardless of sex. About 40% of men experience hair regrowth after 3–6 months. Minoxidil must be used indefinitely for continued support of existing hair follicles and the maintenance of any experienced hair regrowth. Its effect in people with alopecia areata is unclear. Minoxidil is generally well tolerated, but common side effects include burning or irritation of the eye, itching, redness or irritation at the treated area, and unwanted hair growth elsewhere on the body. Exacerbation of hair loss/alopecia has been reported. Severe allergic reactions may include rash, hives, itching, difficulty breathing, tightness in the chest, swelling of the mouth, face, lips, or tongue, chest pain, dizziness, fainting, tachycardia, headache, sudden and unexplained weight gain, or swelling of the hands and feet.Temporary hair loss is a common side effect of minoxidil treatment. Manufacturers note that minoxidil-induced hair loss is a common side effect and describe the process as 'shedding'. Alcohol and propylene glycol present in some topical preparations may dry the scalp, resulting in dandruff and contact dermatitis. Side effects of oral minoxidil may include swelling of the face and extremities, rapid and irregular heartbeat, lightheadedness, cardiac lesions, and focal necrosis of the papillary muscle and subendocardial areas of the left ventricle. Cases of allergic reactions to minoxidil or the non-active ingredient propylene glycol, which is found in some topical minoxidil formulations, have been reported. Pseudoacromegaly is an extremely rare side effect reported with large doses of oral minoxidil. Minoxidil may cause hirsutism, although it is exceedingly rare and reversible by discontinuation of the drug. The mechanism by which minoxidil promotes hair growth is not fully understood. Minoxidil is a potassium channel opener, causing hyperpolarization of cell membranes. Theoretically, by widening blood vessels and opening potassium channels, it allows more oxygen, blood, and nutrients to the follicles. This may cause follicles in the telogen phase to shed, which are then replaced by thicker hairs in a new anagen phase. Minoxidil is a prodrug that is converted by sulfation via the sulfotransferase enzyme SULT1A1 to its active form, minoxidil sulfate. Several studies demonstrated that the activity of sulfotransferase in hair follicles predict minoxidil response in the treatment of hair loss. Minoxidil is less effective when the area of hair loss is large. In addition, its effectiveness has largely been demonstrated in younger men who have experienced hair loss for less than 5 years. Minoxidil use is indicated for central (vertex) hair loss only. Minoxidil is also a vasodilator. Two clinical studies are being conducted in the US for a medical device that may allow patients to determine if they are likely to benefit from minoxidil therapy.