Finasteride - Proscar - Propecia Profile

Finasteride/Proscar/Propecia Profile


Pharmaceutical Name: Finasteride
Drug Classification: Reductase Inhibitor
Active Life: 24-48 hours




The drug finasteride is a competitive Type II 5 alpha-reductase inhibitor originally developed to help alleviate some of the symptoms and causes of benign prostatic hyperplasia and then later used to treat male pattern baldness. Finasteride does so via its mechanism by which it inhibits the Type II alpha-reductase which is the enzyme that converts testosterone to dihydrotestosterone, more commonly known by its acronym DHT (1). Therefore finasteride helps in blocking the formation of DHT in users. This is important since 5-alpha-reductase is found in high concentrations in such areas of the body as the prostate and scalp. By inhibiting these interactions in these tissues finasteride can help to reduce the levels of androgenic activity and prevent some conditions from occurring or reduce their severity.

In terms of the use of finasteride for steroid users, it would be related to the easing of several androgenic side effects often associated with the use of some anabolic and androgenic steroids. Of course due to the originally intended medical purpose of the drug steroid users suffering from prostate conditions due to their anabolic steroid use could be well served to use a drug such as finasteride. This will likely ease some of the discomfort caused by the activity of the DHT in the prostate tissue and related conditions. Similarly the androgenic activity of DHT in the scalp leading to hair loss can also prevented in some males with the use of a reductase inhibitor like finasteride. If the hair loss experienced by the user is related to an increase in the concentration and/or level of DHT in the tissue the administration of finasteride can help to reduce or prevent the severity of this side effect. A third side effect that the drug may help with is oily skin and/or acne. This androgenic side effect may be prevented or at the very least reduced in severity with the administration of finasteride. However, anecdotally the results of this have been mixed to say the least and relatively few users administer the drug for this purpose.

For many these actions of finasteride will seem very similar to that of another reductase inhibitor, namely dutasteride. However these drugs do have differences. The major difference between them is that dutasteride targets both Type I and Type II 5-alpha reductase. Finasteride only targets Type II (2, 3). Type I is more heavily concentrated in the liver and skin while Type II is found most prevalently in male reproductive organs. By targeting both types of the enzyme, dutasteride is better capable of reducing more DHT then finasteride and is therefore thought to be more efficient and effective by most. Despite this, it is still not as popular as finasteride but this is likely due to dutasteride having been on the market for a much shorter time as well as not currently being approved medically for use as a preventative measure against male pattern baldness.

Finasteride has also been used as a so-called “masking agent” by some steroid users who are tested either via urine or blood (4). While the mechanism by which this is accomplished will not be discussed in this profile, it should however be noted that most organizations now recognize this fact and will test for finasteride along with anabolic steroids. For this reason users of finasteride who may be tested for such substances should be aware of this fact beforehand.


Use/Dosing

In terms of dosing for the drug, while topical application of finasteride can yield results, most physicians will recommend and most users will choose to administer the drug orally. This is due to the greater rate of bioavailability compared to topical application. The bioavailability of finasteride, when taken orally, ranges in the area of sixty-five percent of a one milligram tablet in clinical studies (5). It should also be noted that the bioavailability of finasteride was not affected when taken with or without food or liquids. Maximum suppression of DHT conversion occurs within twenty-four hours of administering a one milligram dose orally. This maximum suppression is approximately sixty-five of the total DHT conversion (5).

As for the size of dosage required, it depends on the reaction of the user. Most males that are prescribed finasteride as part of a medical treatment are most often given doses of one milligram per day. This may be more then necessary however. Anecdotally some users have indicated that doses of .5 milligrams per day or one milligram every other day have had the desired effect for some users. However other users may require larger doses to reap the benefits of the compound. For the most part these doses range from 1.5 milligrams per day to as high as five milligrams per day or higher. When increasing one’s dosage however a user should make these increases gradually so as to gage their response to the compound and avoid a dramatic onset of negative side effects.

Finasteride is still a relatively new drug on the market and long-term studies on it continue to be done. However there are no indications that users have to limit themselves in regard to the duration of their use of the drug. It was designed to be administered for long periods of time and is seemingly well tolerated by the majority of users. For this reason steroid users should feel free to use finasteride for extended periods of time if they feel it necessary. The only limiting factors being any side effects that arise for the individual taking the compound or else the cost of the drug itself, or of course the fact that it is no longer required. Also, when discontinuing the use of finasteride there appears no need for a tapering of the drug to prevent a major rebound in DHT levels of the user. While obviously these levels will return to their normal concentrations no dramatic rise should be seen by the user.


Risks/Side Effects

For the most part the side effects associated with the use of finasteride are relatively minor and will not jeopardize the general health of the user. It appears that all of the reported side effects are related to its action as a reductase inhibitor and the lack of dihydrotestosterone (DHT) circulating in the system of the user when using this drug. Toxicity is not a concern as even with extremely large doses run for long durations (eighty milligrams per day for a total of three months in one study [5]) no adverse reactions are observed.

The most common side effect reported with the administration of finasteride is seemingly sexual dysfunction and/or a reduction in sex drive (6). This is due to DHT playing a significant role in sex drive with it also being found in high concentrations in male sex organs playing a role in their proper function. To a lesser extent some users report that their strength is reduced when using finasteride and this can also be directly related to the drop in DHT present in the user. Similarly this may also result in a small reduction in muscle mass depending on the amount inhibited and the individual body chemistry of the user.

Despite the lack of long term side effects for users there is one significant side effect that may affect some males. This is namely temporary sterility (7). This effect does appear to be only temporary with no long term damage to the ability of the user to produce healthy sperm capable of procreation once administration of the drug ceases. However users hoping to bear children will likely have to discontinue their use of the drug to enhance their chances of success. Finasteride is so successful at causing temporary sterility in males that it has been studied as part of a combination of drugs that could be used as male birth control. However these studies remain in their preliminary stages. In any case, many steroid users will already be experiencing temporary sterility due to their use of anabolic steroids so this will not be an additional burden for the vast majority of users.

DHT exhibits the ability to compete for the opportunity to bind to the aromatase enzyme. If the amount of DHT is reduced this could cause an increase in the chance that estrogenic side effects (such as water retention, gynocomastia, etc.), due to less competition for the aromatase enzyme, could arise. Aromatizable compounds such as testosterone therefore have a greater likelihood to attach to this enzyme and estrogen levels could increase. While this may not be a significant problem for most users an increase in estrogenic side effects may be experienced by some who include finasteride in their cycle(s) so greater attention may be needed to be paid to such concerns.

It should also be noted that finasteride products should not be handled by pregnant or lactating women. Birth defects could occur and it is unknown whether finasteride is excreted in human breast milk; if so this could be harmful to a nursing child. It is also because finasteride can be absorbed fairly well through the skin that it should not be touched or handled by women who may be or are pregnant or nursing (8).



References

1. Finn DA, Beadles-Bohling AS, Beckley EH, Ford MM, Gililland KR, Gorin-Meyer RE, Wiren KM. A new look at the 5alpha-reductase inhibitor finasteride. CNS Drug Rev. 2006 Spring;12(1):53-76.

2. Robaire B, Henderson NA. Actions of 5alpha-reductase inhibitors on the epididymis. Mol Cell Endocrinol. 2006 May 16;250(1-2):190-5.

3. Makridakis N, Reichardt JK. Pharmacogenetic analysis of human steroid 5 alpha reductase type II: comparison of finasteride and dutasteride. J Mol Endocrinol. 2005 Jun;34(3):617-23.

4. Graf-Baumann T. Medicolegal aspects of doping in football. Br J Sports Med. 2006 Jul;40 Suppl 1:i55-7.

5. RxCC Rx Care Canada. Website: http://www.rxcarecanada.com. 2006.

6. Makridakis N, Reichardt JK. Pharmacogenetic analysis of human steroid 5 alpha reductase type II: comparison of finasteride and dutasteride. J Mol Endocrinol. 2005 Jun;34(3):617-23.

7. Matthiesson KL, Stanton PG, O'Donnell L, Meachem SJ, Amory JK, Berger R, Bremner WJ, McLachlan RI. Effects of testosterone and levonorgestrel combined with a 5alpha-reductase inhibitor or gonadotropin-releasing hormone antagonist on spermatogenesis and intratesticular steroid levels in normal men. J Clin Endocrinol Metab. 2005 Oct;90(10):5647-55.

8. Iorizzo M, Vincenzi C, Voudouris S, Piraccini BM, Tosti A. Finasteride treatment of female pattern hair loss. Arch Dermatol. 2006 Mar;142(3):298-302.