How finasteride can be used to treat acne

Conditions of androgen excess or hyperandrogenism are associated with increased sebum production which in turn leads to acne formation. Anti-androgens are drugs that block the actions of androgens and thus help reduce acne formation. Commonly used anti-androgens are cyprotene acetate, spironolactone, flutamide and finesteride. Here we discuss the use of finasteride in acne.

Indications:

1) Women with proven ovarian or adrenal hyperandrogenism
2) Women with acne associated with hirsutism, with worsening before periods.
3) Acne that are severe and resistant to other forms of treatment

Mechanism of action:

Dihydrotestosterone (DHT) the primary androgen that stimulates sebum production. DHT is produced from testosterone within the peripheral tissues such as skin by the action of the 5 alpha-reductase enzyme and is approximately 5-10 times stronger than testosterone. The activity of 5-alpha-reductase in sebaceous glands in skin is correlates with the propensity of skin to have acne i.e. it is greater in sebaceous glands in acne prone compared to non-acne prone skin.

There are two forms of 5 alpha – reductase - type 1 and type 2. Finasteride is a specific inhibitor of the 5 alpha-reductase 2 enzyme, the enhanced activity of which leads to the development of androsterone and ultimately to the formation of severe acne in adult women.

Effectiveness:

Finesteride is similar to other well-established anti-androgen treatments in hyperandrogenic acne. In patients who respond well to treatment, acne improves rapidly and can even be completely eliminated after two to three months. Moreover, only a very low dosage of 5 mg per day of this anti androgen receptor blocker is effective in acne reduction.

Finasteride compared to other anti androgens

Finasteride is reported to successfully reduce acne lesions but total acne scores are reduced by approximately 36%, which is lower compared to another novel anti androgen flutamide. Even low doses of flutamide at 250 mg daily are observed to be as effective as cyproterone acetate in acne reduction and reduced acne scores by 60% in majority of patients. This may be explained by the fact that finasteride inhibits the 5 alpha-reductase 2 enzyme while acne development is associated mainly with 5alpha-reductase 1 enzyme.

Associated side effects

Side effects from finasteride are much lower compared to flutamide and cyproterone acetate, in fact no side effects have been reported with 5mg dosage finasteride. It does not effect the pattern of menstrual flow nor does it affect the blood sugar level or liver enzymes.

Finasteride is an anti-androgeneic hormone and hence is teratogenic, i.e. it can cause birth defects in children conceived whilst a woman is on this medication. When women of child bearing age are given finasteride by doctors, they are also required to use oral contraceptives to prevent pregnancy. Women who wish to get pregnant should stop using this drug prior to conception.

Conclusion:

Finasteride is less beneficial or effective compared to the antiandrogen flutamide. It is however still an effective androgen receptor blocker and is successful in treating severe androgenic acne.