Male pattern baldness or androgenetic alopecia is caused by the effects of the male hormone dihydrotestosterone (DHT) on genetically susceptible hair follicles that are present mainly in the front, top, and crown of the scalp (rather than the back and sides). DHT causes hair loss by shortening the growth, or anagen, phase of the hair cycle, causing miniaturization (decreased size) of the follicles. The effected hair becomes progressively shorter and finer until it eventually disappears.
DHT is formed by the action of the enzyme 5-alpha reductase on testosterone. Finasteride is a synthetic 4-azasteroid compound, is a specific inhibitor of steroid Type II 5a-reductase, an intracellular enzyme that converts the androgen testosterone into 5a-dihydrotestosterone (DHT)in the hair follicle. Finastride is the only FDA approved medication for hair loss prevention.
Finasteride causes a significant drop in both scalp and blood levels of DHT and its effect is felt to be related to both of these factors. Finasteride produces a rapid reduction in serum DHT concentration, reaching 65% suppression within 24 hours of oral dosing with a 1-mg tablet Serum testosterone levels actually increased by 9%, but this is within the range of normal.
It is commonly thought that finasteride was first conceived as a prostate medication and that, only by chance, was found to prevent hair loss. In 1997, the FDA approved finasteride 1-mg/day (Propecia) for the treatment of male pattern baldness.
Studies have shown that after five years of treatment, 90% of men taking finasteride maintained their hair or increased hair growth. At five years, 48% of men treated with Propecia demonstrated an increase in hair growth, 42% were rated as having no change (no further visible progression of hair loss from baseline) and 10% were rated as having lost hair when compared to baseline.These hairs were significantly larger than the fine, miniaturized hair characteristic of balding. In the “Hair Weight Clinical Study,” a 34% increase in hair weight was observed
Using Finasteride Finasteride should be taken once daily with or without meals. Patients must take Finasteride for one year or longer before its effects in preventing hair loss and re-growing hair can be accurately assessed. Finasteride takes up to a year or more to exert its full effects in both preventing hair loss and in re-growing hair. During the first six months you may note some thinning of your existing hair. This may be due to either progression of your hair loss before finasteride has had a chance to work or some shedding of miniaturized hair that makes way for the new healthy anagen hair to grow. It is important to be patient during this period.
Long-Term Benefits and Risks The effects of finasteride are confined to areas of the scalp that are thinning, but where there is still some hair present. It does not grow hair in areas that are completely bald. Although it can regrow hair in thin areas, the major benefit of finasteride seems to be in its ability to slow down or halt hair loss. Results generally peak around one year and then are stable in the second year or decrease very slightly. Although the long-term ability of finasteride to maintain one’s hair is unknown, the majority of men find that after 5 years the medication is still working.
The benefits of finasteride will stop if the medication is discontinued. Over the 2-6 months following discontinuation, the hair loss pattern will generally return to the state that it would have been if the medication had never been used.
Side Effects Side effects from finasteride at the 1-mg dose are uncommon, but reversible. The one- year drug related side effects were 1.5% greater than in the control group. The data showed that 3.8% of men taking finasteride 1mg experienced some form of sexual dysfunction verses 2.1% in men treated with a placebo. The five-year side effects profile included: decreased libido (0.3%), erectile dysfunction (0.3%), and decreased volume of ejaculate (0.0%).
TABLE 1 Drug-Related Adverse Experiences for PROPECIA (finasteride 1 mg) in Year 1 (%) MALE PATTERN HAIR LOSS
(Decreased Volume of Ejaculate)
Discontinuation due to drug-related sexual adverse experiences
Most reported cases of sexual dysfunction occurred soon after starting the medication, but there have been reports of sexual dysfunction that have occurred at later points in time. The sexual side effects were reversed in all men who discontinued therapy, and in 58% of those who continued treatment. After the medication was stopped, side effects generally disappeared within a few weeks. When finasteride is discontinued, only the hair that had been gained or preserved by the medication is lost. In effect, the patient returns to the level of balding where he would have been had he never used the drug in the first place. No drug interactions of clinical importance have been identified.
Side Effects: Adverse reactions related to the breast, including breast tenderness or breast enlargement (gynecomastia), occurred in 1 in 4000 ( 0.4%) of men taking finasteride 1-mg (Propecia), but this was no greater than in the control group. Other side effects that were not statistically significant included hypersensitivity reactions including rash, pruritus, urticaria, swelling of the lips and face, and testicular pain. Contrary to the common belief it does not grow body hair thicker.
Effects on PSA Finasteride causes a decrease in serum PSA (prostate specific antigen) by approximately 50% in normal men. Since PSA levels are used to screen for prostate enlargement and prostate cancer, it is important that your personal physician is aware that you are taking Propecia (finasteride) so that he/she may take this into account when interpreting your PSA results.
Finasteride and Prostate Disease A study in The New England Journal of Medicine, in 2003, on finasteride 5-mg PROSCAR (not finasteride 1-mg, Propecia) reported that in the Prostate Cancer Prevention Trial (PCPT), men treated with finasteride 5mg for seven years had a 25 percent relative risk reduction for prostate cancer compared to the men treated with placebo. The authors also reported that high grade prostate cancers were found in 6.4 percent of the men treated with finasteride 5mg, compared to 5.1 percent of the men in the placebo group.
The authors were concerned that finasteride 5mg prevents or delays the appearance of prostate cancer and that this possible benefit and a reduced risk of urinary problems must be weighed against sexual side effects and the increased risk of high-grade prostate cancer. With new information, it is now felt that the increased incidence of a higher grade cancer was due to the fact that the finasteride shrunk the non-cancerous part of the enlarged prostate, making the cancerous part easier to detect on biopsy.
In fact, in 2009, the American Society of Clinical Oncology and the American Urological Association issued guidelines that recommend that healthy men consider finasteride to lower their level of the hormone dihydrotestosterone (DHT) with the goal of preventing the development of prostate cancer.
Caution during Pregnancy Finasteride use is contraindicated in women when they are, or may be, pregnant. Women should not handle crushed or broken Finasteride tablets when they are pregnant, or may potentially be pregnant, because of the possibilities of absorption of finasteride and the subsequent potential risk to a male fetus. Finasteride tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed.
Exposure of pregnant women to semen from men treated with Finasteride poses no risk to the fetus. Semen levels have been measured in 35 men taking finasteride 1 mg/day for 6 weeks. In 60% (21 of 35) of the samples, finasteride levels were undetectable (<0.2>mg) that had no effect on circulating DHT levels in men (see
Use in Post-Menopausal Women Merck recently carried out a study to evaluate the efficacy of finasteride in post-menopausal women. After one year there was no significant hair growth and, as a result, the study was terminated. An explanation is that hair loss in women is related more to the action of the enzyme aromatase (which is unaffected by finasteride) rather than DHT. It is also possible that the low DHT levels observed in postmenopausal women are responsible for the lack of significant response to finasteride.
Finasteride and Hair Transplantation Finasteride has shown to be useful in complementing a hair transplant for several reasons:
- Finasteride works best in the younger patient who may not yet be a candidate for hair transplantation.
- Finasteride is less effective in the front part of the scalp, the area where surgical hair restoration can offer the greatest cosmetic improvement.
- Finasteride can re-grow hair, or stabilize hair loss, in the crown part of the scalp where hair transplantation may not always be indicated.
For those who choose not to take Finasteride, or who cannot take it due to its side effects, the surgical hair restoration is just as effective. The only difference is that medications can prevent further hair loss whereas surgery cannot. Medications are not needed for a hair transplant to be successful or the transplanted hair to grow and be permanent.
Increasing the Dose We are often asked if one should increase the dose of Finasteride. Although we do increase the dose under certain circumstances, there is no scientific evidence that increasing the dose will have any additional effects. There are published data demonstrating that 5 mg is no better than 1 mg from controlled clinical trials.
Patient Monitoring It is recommended that men aged 50, or over, should inform their regular physicians or urologists that they are taking Finasteride 1mg. It is also recommended that all men aged 50 or over have a routine annual evaluation for prostate disease, regardless of whether or not Finasteride is used. For those patients who are black and/or who have a family history of prostate disease, these recommendations would apply beginning at age 40. An evaluation may include a rectal examination, a baseline PSA, and other tests that your examining physician feels are appropriate.The above are general guidelines recommended for all men of appropriate age, regardless of whether they use Finasteride or not. Specific recommendations for each Patient should be based upon the judgment of his own physician.
Common Misconceptions about Finasteride
Myth: Women can’t touch the medication. Fact: Pregnant women should not handle crushed or broken tablets.
Myth: It only works in the crown. Fact: It potentially works any where on the scalp where there is some hair, even in the front of the scalp.
Myth: Once you start it you must take it for ever. Fact: You can stop the medication any time you want – you just lose its benefits when one stops.
Myth: Finasteride lowers testosterone Fact: The medication, on average, causes a rise in serum testosterone levels by 9%.
Myth: The sexual side effects are frequent and irreversible. Fact: The sexual side effects occur in 2% and are reversible when the medication is stopped.
Myth: Finasteride causes birth defects if a man takes it when his wife is pregnant. Fact: Exposure of pregnant women to semen from men treated with Propecia poses no risk to the fetus.
Myth: Propecia was originally a prostate medication that was found to prevent hair loss. Fact: Propecia is not a prostate medication that was by chance noted to have a side effect of hair growth, it is a medication that was known since its discovery that it could grow hair.
Tips on Using Finasteride (Propecia/ Finax)
Finasteride is a prescription oral medication that is now generic (Proscar in the 5mg dose). This formulation is just as effective as the brand name Propecia and is about 1/3 the cost.
The general starting dose of finasteride for hair loss is 1mg a day. For this dose, you can either take one 1mg Propecia tablet or ¼ of a 5mg tablet of generic finasteride each day. Finasteride does not have to be cut into equal parts to be effective. Just cut it into the recommended of pieces and take one piece each day.
Finasteride can be taken any time of the day without regard to food or other medications.
You may experience shedding during the first 3-6 months of treatment. This generally is an indication that the medication is working. Do not stop the medication if you see shedding. It takes up to a full year to see the effects of Finasteride, so be patient.
For more details: http://www.rxlist.com/cgi/generic/propecia_cp.htm