Finasteride as a treatment for hirsurism

Information on hirsutism and hair removal treatments
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Cyproterone acetate
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Finasteride for Hirsutism

For women suffering from excess, unwanted hair problems, treatment is available in a variety of options. Their condition, diagnosed either as hirsutism or hypertrichosis, require clinical treatment in either medical or cosmetic forms.

The medical treatment of this ailment includes a number of options like oral contraceptive pills (OCPs), spironolactone, antiandrogens and insulin-sensitizing agents such as metformin, pioglitazone, flutamide and last but not the least finasteride. Combinations of the above medications together are also often prescribed for better results.

Finasteride activity

Finasteride like flutamide has the same effects as spironolactone and cyproterone acetate. Flutamide, spironolactone and cyproterone acetate block or suppress the activity of androgen, the main steroidal hormone that regulates human hair growth. Hence, the three are called androgen receptor blockers. Whereas finasteride reduces androgen-dependent hair development by hindering 5a-reductase (isoenzymes type 1 and 2) action and the peripheral conversion of testosterone to dihydrotestosterone. The Food and Drug Administration has recognized the use of finasteride for the treatment of benign prostatic hyperplasia. It was first marketed in 1992 for the treatment of prostatic disorders.

Effectiveness of finasteride treatment

Finasteride has proven effective for the treatment of hirsutism in women in prescribed amounts of 5 mg per day. It has been also been analyzed that in some hirsute women even 50 percent of the regular daily dose of finasteride (i.e. 2.5 mg) is as effective. Both the 2.5 and 5 mg doses showed similar results in treating hirsutism after 6 and 12 months of use.

There have also been research-based comparisons of the effectiveness of finasteride vis-a-vis the two androgen blockers spironolactone and flutamide. It was conducted in a ‘placebo-controlled, double-blind randomized’ group of 40 patients with mild to severe hirsutism. The study reported noticeable improvements in both F–G scores and hair shaft diameter after 6 months of daily treatment with 5 mg of finasteride, 100 mg of spironolactone and 250 mg of flutamide all at the backdrop of a placebo control.
All the groups taking the respective medications reported similar hirsutism scores or measurement of hair shaft diameter. None reported any adverse affects either, except for transient polymenorrhea in 50 percent of the women using spironolactone, though this did not stop its usage.

In another research that undertook a comparative study of the action of 5 mg of finasteride daily against spironolactone at 100 mg a day in 14 hirsute women, it was reported that both were equally successful at slowing down hair production after 3 months of use. There were even better results after another 3 months of usage. However, many experts consider finasteride a little less effective than the androgen receptor blockers.

Finasteride is also effective in the treatment of acne due to its capability to inhibit 5a-reductase. But since its action on the type 1 isoenzyme (a key factor in acne formation) is very low, a high dose of finasteride is required to block this enzyme. In a research comparing acne afflicted hyperandrogenic cases, those who were administered 5 mg of finasteride with those using 250 mg of flutamide, it was reported that the former reduced acne scores by 36 percent whereas the latter improved scores by 60 percent. At the same time, finasteride improved acne scores in only 33 percent of the treated women whereas flutamide improved acne scores in 75 percent. There have also been studies that have recorded significant placebo effect in acne treatments with finasteride.

Side effects of finasteride treatment

All androgen blocking medication have similar effectiveness; hence side effects have a vital role to play in choosing the kind of medication. The good news is that finasteride reports the least side effects among all the drugs used for curing hirsutism.

However, teratogenicity (feminization and hindrance to the normal development of the male external genitalia) does occur frequently and is the problem area. This happens since finasteride interferes with the transformation of testosterone to DHT. Hence, its daily use results in an increase in serum testosterone levels.

Moreover, feminization occurs due to the inhibition of 5 a-reductase. But teratogenic effects (feminization) are seen in all androgen blockers and they should be used only with safe and sufficient antidotes of contraceptive.

Moreover, recent studies have also reported that lower doses of spironolactone, flutamide and finasteride have shown similar success in the treatment of hirsutism when compared to higher doses, while reducing side effects. Lower doses of these drugs have also proved effective in treating women with acne vulgaris.

Apart from this, finasteride may show additional side effects like minimal gastrointestinal disturbances, headaches, dry skin and decreased libido.