Skip to main content

AGA: Androgenetic Alopecia: Facts and Options

AGA: Androgenetic Alopecia: Facts and Options

A ndrogenetic alopecia (AGA) is a common, genetically determined hair disorder that affects both men and women. Though our society generally accepts the fact that men experience balding, those who endure this inevitable fate are still bothered. Now let’s think about how we approach all of our patients who have AGA. It’ s our responsibility as physicians to help these patients by trying to stop the progression of AGA and if possible, reverse it. We must be aware of the cause of this condition as well as all of the available treatment options. So let’s turn now to these topics so we can face our future patients with greater confidence in our skills and increased knowledge of their plight. Just the Facts AGA presents in roughly 50% of men and as many as 13% of premenopausal women, though its incidence increases greatly in postmenopausal women. Hormonal factors and genetic predisposition play a role in AGA. Note that the prevalence and severity of AGA increase with age. Hair normally grows in cycles of 2 to 6 years. In people who have AGA, these cycles are shortened to 6 to 8 months. Over time, hairs become miniaturized and progressively thinner, finer and shorter. Clinically, this process presents as thinning of the scalp hair, commonly referred to as balding. Dihydrotestosterone (DHT) plays a key role in the development of AGA. DHT is made from testosterone via the enzyme 5 alpha-reductase and is important during the prenatal period, specifically in the development of male fetuses’ external genetalia. Postnatally, however, DHT serves only two roles: scalp hair loss and prostate gland enlargement in men who are genetically sensitive to DHT. DHT has shown no beneficial effect in adult men. The enzyme 5 alpha-reductase exists in two isoenzymes: Type I and Type II. We’ll be looking at the role of 5 alpha-reductase Type II because this one is localized in the hair and in the prostate. Individuals who have a genetic absence of 5 alpha-reductase Type II have shown protection against AGA and prostate enlargement. How to Nip it in the Bud We need to explain all options to patients who suffer from AGA. Let them choose the option that they’re most comfortable with. While wearing a hair piece may make one person more confident in public, another might just opt for surgery to reap permanent results. Current treatment options for hair regrowth fall into three categories: • Camouflaging. This is probably the oldest approach to dealing with hair loss. Hairpieces, hair weaves and hair enhancers such as shampoos, sprays and mousses are the most common types of camouflaging methods. • Surgical treatments. This category includes hair transplants and scalp reduction procedures. • Medical treatments. These currently include minoxidil (Rogaine) and finasteride (Propecia). A Closer Look at Hair Transplantation Hair transplantation is the most common surgical treatment option for hair loss. Professionals have made significant advances in this field since its introduction. Older methods used larger punch grafts, while the trend toward smaller minigrafts has gained increasing popularity and success over the past several years. A combination of minigrafts and follicular units has recently been advocated in producing a more natural hairline and restoring hair density. Laser-assisted hair transplantation, which produces small grafts, has also gained popularity, and is used in combination with the more traditional punch techniques. Additionally, CO2 lasers, which are used to make follicular unit recipient sites, allow for improved hemostasis. The procedure is therefore cleaner and easier to perform. However, one problem with the CO2 laser is that there’s more crusting at the site, resulting in greater scabbing. Physicians start most patients who undergo hair transplantation on minoxidil and/or finasteride to help maintain the new grafts and promote diffuse hair growth. Proper patient selection and patient education are critical for achieving successful outcomes of hair transplantation. Therefore it’s crucial to tailor the patient’s expectations with what you can attain, given his particular case. Focus on the Wonder Drugs Minoxidil is a topical treatment for AGA. Reports described that 20% to 30% of patients experienced either maintenance or regrowth of hair. It’s been available for many years, but originally it was available in a 2% solution for use b.i.d. by both men and women. Now Rogaine (minoxidil) is available as a generic solution, and the price has dropped from between $50 to $60 a month to $10 a month. A 5% solution is currently available (though not in generic form) that costs about $50 a month. Minoxidil’s various proposed mechanisms of action include, an increase in hair matrix volume, an increase in the length of the growth phase of hair and vasodilation, though it’s not completely clear which of these processes are responsible for the drug’s action. Thanks to the wonders of modern science, finasteride has offered a breakthrough in the treatment of AGA. It’s the first and only FDA-approved oral agent indicated for AGA in men only. Finasteride has a direct affect on DHT. Finasteride inhibits 5 alpha-reductase Type II, thus lowering circulating DHT. This lowering of DHT appears to further inhibit miniaturization of hair follicles and helps return miniaturized hairs to normal terminal hairs. Although researchers have compiled the results of the 5-year data on finasteride, this data has not yet been published. Expect to see the published data early this year. The data thus far has shown that two out of three men regrew natural, visible hair in the vertex studies and that five out of six men maintained their hair count. The 5-year data suggests similar results. Overall, the results suggest that the sooner a patient starts finasteride, the better his chances of either maintaining his hair or regrowing new hair. It’s also been shown that discontinuation of finasteride gradually leads to a reversal of the beneficial effects over the following 12 months. In general, finasteride takes at least 3 months to show its beneficial effects. Possible adverse side effects Men treated with finasteride have reported such adverse events as decreased libido, erectile dysfunction and ejaculate disorders. It’s important to note, however, that these adverse experiences were rare in clinical studies and were reversible within 3 months of discontinuing treatment. Researchers noted decreased libido in 1.8% of men on finasteride compared to 1.3% of men on a placebo. They reported erectile dysfunction in 1.3% of men on finasteride versus 0.7% in those on the placebo. Finally, researchers saw ejaculate disorders in 0.8% of men on finasteride compared to 0.4% in men on the placebo. These adverse events resolved in 100% of men who discontinued therapy, as well as 58% of those continued treatment. Researchers have not identified any drug interactions of clinical importance at this time. Allergic contact dermatitis is a rare side effect sometimes seen. It’s usually from the propelyne glycol in the solution. Also, facial hypertrichosis has been reported in a small number of patients. Otherwise there are no significant systemic side effects. Including Women in Treatment Although finasteride is indicated for the treatment of AGA in men only, interest has increased as to whether it can help women who suffer from AGA. According to a recent study conducted by Dr. Vera Price, finasteride didn’t slow hair loss among postmenopausal women who experienced AGA. One hundred thirty-seven postmenopausal women enrolled in a 1-year, double-blind, placebo-controlled multi-center trial. Only postmenopausal women were accepted because of the potential teratogenic effects of finasteride. Some researchers have suggested trying higher doses of finasteride, such as the 5-mg dose known as Proscar. No studies have been reported to evaluate the efficacy of higher dosing. There are a few early studies evaluating the efficacy of minoxidil in women. The results are basically similar to those in men. What Does the Future Hold? A new drug for the treatment of prostate enlargement is awaiting FDA approval. This drug, Dutasteride, works by inhibiting 5 alpha-reductase Types I and II, while finasteride only inhibits Type II. Few studies are available regarding Dutasteride’s efficacy in treating AGA because the manufacturer isn’t seeking approval for the treatment of this condition. However, it’s interesting to note that both Type I and Type II 5 alpha-reductase are localized in the hair follicle. Clearly, we’d need to see additional studies to evaluate Dutasteride’s role in treating AGA. Treat with Compassion Hopefully now you feel more confident about your knowledge of AGA. Although you can’t prevent this condition from occurring in patients, you can help them halt its progression and in some cases, even reverse it. Your patients will graciously accept any and all information and treatment you offer them, so make sure you keep their interests, fears and concerns in mind when discussing their condition.
Back to Top