Androgenetic Alopecia Treatment & Management

Only 2 drugs currently have US Food and Drug Administration (FDA)–approved indications for treatment of androgenetic alopecia: minoxidil and finasteride.

Minoxidil

Although the method of action is essentially unknown, minoxidil appears to lengthen the duration of the anagen phase, and it may increase the blood supply to the follicle.^[17] Regrowth is more pronounced at the vertex than in the frontal areas and is not noted for at least 4 months. Continuing topical treatment with the drug is necessary indefinitely because discontinuation of treatment produces a rapid reversion to the pretreatment balding pattern.

Patients who respond best to this drug are those who have a recent onset of androgenetic alopecia and small areas of hair loss. The drug is marketed as a 2% or a 5% solution, with the 5% solution being somewhat more effective. A 48-week study compared the 2 strengths in men.^[18] Findings indicated that 45% more regrowth occurred with the 5% compared with the 2% solution. In general, women respond better to topical minoxidil than men. The increase in effectiveness of the 5% solution was not evident for women in the FDA-controlled studies. Subsequent studies have shown at best a modest advantage to the higher concentration in women. In addition, the occurrence of facial hair growth appears to be increased with the use of the higher-concentration formulation.

Finasteride

Finasteride is given orally and is a 5-alpha reductase type 2 inhibitor.^[19] It is not an antiandrogen. The drug can be used only in men because it can produce ambiguous genitalia in a developing male fetus. Finasteride has been shown to diminish the progression of androgenetic alopecia in males who are treated, and, in many patients, it has stimulated new regrowth.

Although it affects vertex balding more than frontal hair loss, the medication has been shown to increase regrowth in the frontal area as well. Finasteride must be continued indefinitely because discontinuation results in gradual progression of the disorder. A study in postmenopausal women indicated no beneficial effect of the medication in treating female androgenetic alopecia.

Other drugs

Some drugs are not approved by the FDA but are potentially helpful medications.^[20] In women with androgenetic alopecia, especially those with a component of hyperandrogenism, drugs that act as androgen suppressants or antagonists (eg, spironolactone, oral contraceptives) may be beneficial. Evidence exists of an association between androgenetic alopecia, hypertension, and hyperaldosteronism. Spironolactone could play a dual role in treatment.

Dutasteride is another possible treatment for androgenetic alopecia. This drug inhibits type I and type II 5-a reductase isoenzymes and is felt to be 3 times as potent as finasteride in inhibiting the type II enzyme and 100 times as potent in inhibiting the type I enzyme. A phase II study on the use of dutasteride in the treatment of alopecia was carried out in the United States, but no further trials are currently being conducted in the US. However, an ongoing trial is being conducted outside of the United States.

Low-level laser light therapy, in particular a red light hairbrush–like device has been marketed as an over-the-counter technique for hair growth. In a double blind, sham-device controlled, multicenter, 26-week trial, 110 patients in the active treatment group who completed the study showed a significantly greater improvement in overall hair regrowth than did the sham group.^[21] Marketed as the HairMax LaserComb, it has obtained 510K FDA approval for use as a medical device. Note that this approval refers to safety rather than actual efficacy and that the data required for medical devices are quite different from those required to demonstrate the safety and efficacy of drugs.

Androgenetic alopecia is very common; therefore, not surprisingly, it may accompany other forms of hair loss. Cases of telogen effluvium often occur in patients with underlying androgenetic alopecia. Therefore, a search for treatable causes of telogen effluvium (eg, anemia, hypothyroidism), especially in patients with an abrupt onset or a rapid progression of their disease, is indicated.

A selection of clinical trials is as follows:

• Treatment of Androgenetic Alopecia in Males
• Treatment of Androgenetic Alopecia in Females, 12 Beam
• Treatment of Androgenetic Alopecia in Females, 9 Beam
• Association of Polymorphisms in the Androgen Receptor Gene and Finasteride Response in Women With Androgenetic Alopecia
• Study To Assess The Efficacy And Safety Of Dutasteride 0.5mg Once Daily For 6 Months In The Treatment Of Male Subjects With Androgenetic Alopecia (includes results)

Surgical treatment of androgenetic alopecia has been successfully performed for the past 4 decades. Although the cosmetic results are often satisfactory, the main problem is covering the bald area with donor plugs (or follicles) sufficient in number to be effective. Micrografting produces a more natural appearance than the old technique of transplanting plugs.

A 2009 review of surgical procedures concluded that both patients and physicians alike are pleased with the results of contemporary hair transplantation.^[21] Patients with less than 40 follicular units/cm² in their donor areas are poor candidates for the procedure. Scalp reduction has been attempted to decrease the size of the scalp to be covered by transplanted hair. However, the scars produced by the reduction technique often spread and become more noticeable with time.

Hair weaving techniques are available, and, together with hairpieces, they offer the patient a prosthetic method of coverage.

Also see the eMedicine articles Hair Transplantation and Hair Transplantation, Follicular Unit Transplant Method.