Hair loss in men : Drug Update
Author/s: Mitchel L. Zoler
The treatment of hair loss in men has improved vastly in recent years, thanks mostly to two drugs that promote hair growth and improve the appearance of existing hair: finasteride and minoxidil.
One of two disorders, androgenetic alopecia or alopecia areata, is generally responsible for hair loss in young and middle-aged men.
Androgenetic alopecia, also known as male pattern baldness, causes a characteristic pattern of hair loss, including temporal recession of the hair, thinning of the hair at the frontal and vertex regions of the scalp, and complete loss of hair with the exception of some fringing. It usually begins before the age of 40--sometimes as early as age 12--and it affects about half of the male population before they reach the age of 50.
Finasteride and minoxidil are the only drugs that are approved to treat this type of hair loss, although estradiol has also been used with some success. Both finasteride and minoxidil promote hair growth, slow hair loss, and increase the length and diameter of existing hair.
Alopecia areata, unlike androgenetic alopecia, is assumed to have an autoimmune cause. Patients with this condition may have small patches of hair loss that regrow spontaneously, or they may have extensive patches of hair loss that do not resolve.
Treatment with minoxidil is generally beneficial for stimulating hair growth in men with mild or moderate alopecia areata; a 40% response rate is typical. How ever, minoxidil will not help men with one of the most severe forms of alopecia areata, in which all the scalp hair is lost: alopecia totalis. Anthralin is another main stay of therapy for alopecia areata, as are glucocorticoids, which can be used topically, intralesionally, or orally. The preferred glucocorticoid treatment is intralesional injections of triamcinolone.
Psoralen with ultraviolet A therapy is a more controversial treatment for alopecia areata. Although it works well, long-term therapy is necessary to maintain the effects, and this long-term use may lead to several health problems. Topical immunotherapy is also showing promise for treating alopecia areata and is currently under study. Patients with alopecia areata should be referred to a specialist for treatment.
Finasteride
Oral medication. Used for androgenetic alope- (Prapecia) cia only. Slows hair loss, increases hair growth, and improves appearance of hair. Possible sustained effect following discont- inuation of drug. Responses very widely. Men with mild to moderate hair loss respond better than do those with complete baldness or bitemporal recession. Men older than 60 tend to respond more poorly than do younger men. Study results show that overall, about two-thirds of patients treated with finaster- ide will have improved scalp coverage. Good safety profile, but use with caution in men with abnormal liver function. No dosage adjustments are necessary based on age, but tose older than 60 may have limited response. Side effects such as decreased libido, erect- ile dysfunction, and ejaculatory dysfunction occur rearely, disappear over time during prolonged treatment, and resolve completely and rapidly when drug is discontinued. Long- term side effects are unknown.
Minoxidil
Topical drug, used for both androgenetic (Rogaine) alopecia and alopecia areata. Available over the counter in two strengths. The 5% solution has been shown to promote 45% more hair grow- th than the 2% solution, and the 5% solution increases the diamter of the hair shaft. No age-related dose restrictions. Recent reports suggest that 98% of patients have some degree of response. Can be used with finast- eride, although data on the efficacy of this approach are lacking. Good safety profile. Side effects may include scalp irritation, dryness, scaling, and itching, all of which are mild and reversible. Major drawback is that it must be used indefinitely to maintain effects.
Triamcinolone
For alopecia areata. Used intralesionally by acetonide injecting small volumes into the middermis at several sites spaced about 1 cm apart. Drug concentration of 5mg/mL is typical but can range from 2.5 mg/mL to 10 mg/mL. Hair regrowth occurs in 2-3 months in most patie- ents. About 90% of patients with mild disease respond; about 40% of patients with alopecia areata totalis or universalis respond. Main side effect is skin atrophy, but this can be minimized by using small volumes and by spacing injections at 4- to 6-week intervals. All patients with alopecia areata should be referred to a specialist. Topical or oral glucocorticoids also can be used to treat alopecia areata, but intralesional injection is preferred. Topical glucocorticoids work best when used in combination with minoxidil or anthralin. Oral steroids are associated with a number of dangerous side effects.
Anthralin
Topical agent for alopecia areata. One of the (Drithocreme) mainstays of therapy. Safe and often used for patients with extensive hair loss. Results may be seen within a few months; good hair growth occurs in 25% of men after 6 months. Skin irritation is common and can be avoided by removing the cream within an hour.
Estradjol
Topical agent for androgenetic alopecia. Does n't lead to new hair growth but slows loss of existing hair. Most men can tolerate treat- ment when used every other day, and most report market decreases in hair loss. Side effects including palpitations, light- headedness, breast tenderness and enlarge- ment, and decreased libido can also occur. Estradiol solution is not marketed; it must be made to order by a pharmacy.
All Comments based on the expertise of the following:
Dr. Mark Lebwohl, professor and chairman of the department of dermatology, Mount Sinai School of Medicine, New York.
Dr. Zoltan Trizna, assistant professor of dermatology, Texas Tech University, Lubbock.
Dr. Walter Unger, codirector of dermatologic surgery, University of Toronto; codirector of cosmetic dermatologic surgery, Mount Sinai Hospital, New York.
