Q: Are there DHT blockers that are sold in the pharmacy over the counter?
A: The only effective DHT blockers are finasteride (Propecia, Proscar) and dutasteride (Avodart).
These medications require a doctor’s prescription and are not sold OTC. Nizoral is a topical shampoo for seborrhea (a type of dandruff) that is sold over the counter, but it is not effective in treating hair loss.
Q: I have been using Propecia since it was released to the public in 1998 and have found it to work very well. Recently, its effectiveness has stopped and my hairs are miniaturizing again. I am going to increase the dosage to 1/2 a pill Proscar every day. How long will the increased dosage take to stop the miniaturizing process?
A: It seems to take the same time to work as when you initially started Propecia.
When patients increase their dose, I rarely see re-growth, but rather the expectation is that further hair loss will be decreased. When it does work to actually re-grow hair, we sometimes see an initial period of shedding, similar to when finasteride was first started.
Q: Will Propecia and Minoxidil reverse some of the miniaturization going on with someone with thinning hair? If I do need a hair transplant will I have to stay on these medications?
A: Yes, both minoxidil (Rogaine) and finasteride (Propecia, Proscar) affect the miniaturization of the hair follicles and help restore the shrunken follicles to cosmetically viable hair.
Minoxidil works by directly simulating miniaturized follicles to grow, whereas finasteride blocks DHT, the hormone that causes hair to miniaturize and eventually fall out.
Finasteride is much more effective than minoxidil in preventing or reversing the miniaturization process and it is so much more convenient to use that we generally suggest finasteride after a hair restoration procedure, but rarely recommend minoxidil.
Q: My friend is taking Avodart, he bought it over the internet. Is it safe to take?
A: Avodart (dutasteride 0.5mg) was approved by the FDA for the treatment of prostate enlargement in men in 2002. Avodart has not been approved for the treatment of androgenetic hair loss, although physicians can use an approved medication in ways other than for which it was specifically approved. That said, the use of dutasteride certainly requires a doctor’s supervision.
Like finasteride (the active ingredient in Proscar and Propecia), dutasteride blocks the enzyme 5-alpha reductase that converts testosterone to DHT (DHT is a key hormone that causes hair loss). However, unlike finasteride, which only inhibits the Type I form of the enzyme, dutasteride inhibits both the Type I and Type II forms. This combined effect lowers circulating DHT more with dutasteride than with finasteride, but also increases the incidence of its side effects.
The Type II form of the enzyme (blocked by finasteride) is found predominantly in the hair follicle. The Type I form of the enzyme has been found in the scalp and sebaceous glands, and many other parts of the body, but its exact role in hair growth has not been determined. It is felt that dutasteride’s ability to dramatically lower serum levels of DHT is what makes it a more potent medication in hair loss.
When considering the safety of dutasteride, one should consider the following:
Q: I have a 19-year-old son who is suffering from hair loss. I wonder if that will affect him in years to come if he starts taking it?
A: Finasteride was approved in 1992 as Proscar and as Propecia in 1997, so there is a lot of clinical data so far. Remember that over time, additional long-term data and clinical experience will be available. For example, we have 14 years of experience with the medication. By the time your son has been on it for 10 years, there will be 24 years of clinical experience with the medication, so judgments with more long-term information can be made at that time.
The one question that has come up is that a study showed that finasteride 5mg (Proscar) decreased the incidence of prostate cancer by 25%, but some of those in the study who developed prostate cancer had a higher grade of tumor. It is now felt that since finasteride shrinks the enlarged, but benign, tissue surrounding the prostate cancer, the malignant part in the center of the tumor was more easily reached with the needle biopsy, giving a false positive reading in the study. Supporting this explanation is the fact that those on Proscar did not have a more severe course from their cancer than those not taking the medication.
 |
 |
 youtube |
 flickr |
 |
 myspace |
Disclaimer: The purpose of the Hair Transplant Blog is to provide the public with general information on hair restoration. Information provided on this site should not be used for medical diagnosis and/or treatment.
© 2009 Bernstein Medical, P.C. All Rights Reserved.