New drug
offers oral route for male baldness.
January 19, 1998
Just short of grasping for Rapunzel's luxurious
locks, men desperately seeking to halt the inevitable balding process have
smeared, smudged, massaged, and shampooed dozens of hair-promising gels,
creams, and lotions onto their heads. But until now, they've never popped a
pill.
Manufactured by Merck & Co., Propecia (finasteride), 1 mg, is the first
oral medication to leap out of the pipeline for the treatment of male pattern
hair loss (androgenetic alopecia). But finasteride is already available in a
5-mg strength under the brand name Proscar for the treatment of symptomatic
benign prostatic hyperplasia (BPH).
What triggered Merck's entrance into the hair market? "Well, the story
goes back a long way to the discovery of males who were born with the absence
of 5-alpha-reductase--an enzyme that converts testosterone to the active form,
dihydrotestosterone [DHT]," recalled Ronald Savin, M.D., clinical
professor of dermatology at Yale University. He said that these isolated
individuals--born with ambiguous genitalia that resolved at onset of
puberty--never suffered the perils of androgenetic alopecia, prostate swelling,
or prostate cancer.
After further research, it was determined that the balding scalp of men with
androgenetic alopecia contained increased amounts of DHT, compared to hairy
scalps. And since finasteride is a selective type II 5-alpha-reductase
inhibitor--acting primarily in the scalp and prostate to prevent DHT
formation--its use for the just-approved indication makes sense.
What kind of results can one expect from the product? According to Savin,
finasteride's effects vary among individuals, with a greater increase in hair
growth noted on the back and top of the scalp than in the front. Men studied
were aged 18-41 and had mild to moderate hair loss of the vertex and anterior
mid-scalp areas.
In one analysis, an increase in hair growth--evaluated with the use of
photographs--was demonstrated in 66% of men receiving a 1-mg tablet of
finasteride daily for a period of 24 months, compared with 7% of those given
placebo. Diane Thiboutot, M.D., associate professor, division of dermatology,
Pennsylvania State University, indicated that clinical improvement in hair PAGE
18 Drug Topics January 19, 1998 density was gradual and began at approximately
three months into therapy. Since withdrawal of treatment leads to reversal of
effects within 12 months, continued use is recommended.
Perhaps a more substantial benefit is the drug's ability to prevent hair loss.
In a 24-month follow-up, 17% of men treated with finasteride experienced hair
loss, while 83% had the same or higher hair count. Of those given placebo, 72%
lost hair. "It looks like finasteride is a potent stabilizer, and that's a
tremendous advantage for men just beginning to go bald," said Savin. As
for finasteride's competition, minoxidil, don't be surprised if you see the
topical product joining forces with the tablet. Although controlled studies
have not been conducted, Savin claimed that a minoxidil/finasteride combo--used
in a number of his patients--appears to be more effective in the preservation
of the much-treasured strands than either agent alone.
Finasteride's main snag appears to be its adverse-effect profile, which
includes a decreased libido, erectile dysfunction, and ejaculation disorder.
These effects occurred in less than 2% of men; they resolved in all who
discontinued therapy and in 58% of those who continued on the drug. Gene Memoli
Jr., R.Ph., director of pharmaceutical care, Value Health Care Services Inc.,
feels that although these side effects are rare, they are a significant
concern, since the drug will be dispensed to a large patient population. And
that's not the only worry. Because finasteride undergoes extensive hepatic
metabolism, labeling cautions against its use in patients with liver function
abnormalities.
Finasteride is contraindicated in women who are, or may be, pregnant due to its
potential to cause abnormalities of the external genitalia of a male fetus. To
avoid any risk of absorption, these individuals should not handle crushed or
broken finasteride tablets. Thiboutot disclosed that finasteride is being
evaluated in a pilot study for postmenopausal women suffering from hair loss.
She added that if results are favorable, Merck may initiate larger trials.
Memoli believes the drug will be welcomed by the balding population--perhaps
too hastily. He urges that patients exhaust other alternatives, including hair
weaves and minoxidil, before turning to a systemic drug for cosmetic reasons.
Memoli stressed that patients receiving finasteride be adequately monitored by
a physician.
Propecia is supplied as 1-mg tablets in unit-of-dose bottles of 30 and in a
ProPak carton containing three bottles. The catalogue price to wholesalers and
direct purchasers for the product is set to be $ 1.25 per tablet. The estimated
retail price for the product is expected to be between $ 45 and $ 49 per
month.
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