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Propecia/Proscar (finasteride) and Pregnancy
The information below will help you determine if the use of Propecia/Proscar (finasteride) represents an
increased fetal risk. With every pregnancy, all women have a 3 to 5 percent chance to have a baby with a
birth defect.
What are Propecia and Proscar?
make it more difficult for you to become
Propecia and Proscar are two
pregnant. Animal studies suggest a
different forms of a drug called finasteride,
temporary decrease in male fertility,
which was approved by the FDA in 1992.
however in humans no adverse effect on the
Propecia was licensed in 1997 for the
semen have been found. There are no
treatment and prevention of male pattern
reports linking this medication to human
baldness. Proscar was approved for
infertility or an inability to become
treatment of benign prostatic hyperplasia.
pregnant.
Both are used to inhibit a chemical in the
body called 5-alpha-reductase. Neither
Is there an increased risk for birth defects
Propecia nor Proscar are approved at this
if the baby's father is taking finasteride
time for use in women.
when I become pregnant?
My partner is taking finasteride but is
Studies in animals found that
wondering if he should stop before I
pregnancies sired by male rats that were
become pregnant. Is this necessary and if
given large doses of finasteride did not
so, how long does it stay in the body?
result in babies born with birth defects.
There are no such studies in humans at this
The benefits of taking the medication
time.
and any possible adverse outcomes from not
taking it should be taken into account and
If I touch or handle finasteride tablets
discussed with his healthcare provider
during pregnancy does the baby have an
before deciding to stop treatment. There is
increased risk for birth defects?
no known reason for him to stop taking this
medication while planning a family. If he
Animal studies have shown that
does decide to stop using finasteride, it takes
pregnant monkeys who were given large
on average two days for most of the drug to
doses of finasteride orally had male
be eliminated from the body after the last
offspring with abnormalities of the sex
dose.
organs. There are no human studies. Based
on this information, women are told not to
If my partner decides to continue taking
handle tablets that are crushed or broken
finasteride, will it be more difficult for me
during pregnancy. However, it is highly
to become pregnant?
unlikely that enough of the medication
would be absorbed through unbroken skin
There is no evidence to say that if
during the course of normal handling to be a
your partner is taking this medication it will
problem.
Should my partner stop taking finasteride
while I am pregnant?
REFERENCES:
Cather JC, Lane D, Heaphy MR Jr, Nelson
There is a theoretical, although
BR (1999) Finasteride _ An update and review. Cutis
64:167-172.
highly unlikely, risk for birth defects of a
Drug Facts and Comparison: Finasteride
male fetus's sex organs if the couple has
Merck online: www.merck.com, March 13,
intercourse during the stage of pregnancy
2001.
when the sex organs are developing (8 to 15
Overstreet JW, Fuh VL, Gould J, Howards
weeks of gestation). However, the amount of
SS, Lieber MM, Hellstrom W, Shapiro S, Carroll P,
Corfman RS, Petrou S, Lewis R, Toth P, Shown T,
the drug found in the semen is very small
Roy J, Jarow JP, Bonilla J, Jacobsen CA, Wang DZ,
and is not felt to be enough to harm a male
Kaufman KD (1999) Chronic treatment with
baby.
finasteride daily does not affect spermatogenesis or
semen production in young men. The Journal Of
If my partner stops using Propecia will
Urology 162: 1295-1300.
"Propecia discontinuation prior to or during
there be side effects?
pregnancy." Product Monograph: Merck Frosst,
Quebec, Canada 2000.
Propecia must be used daily for three
Reprotox: "Finasteride" RTC: 3528, July 1,
months, on average, before results can be
2000.
seen. Continued use is recommended to
Reprotox: "Paternal Exposures" RTC: 1188,
June 1, 2000.
sustain this benefit. There is no lasting
Rittmaster, RS (1994). Drug Therapy:
benefit if treatment is stopped, and there will
Finasteride. New Engl J Med 330: 120-125.
be a reversal of any benefits within twelve
Wise LD, Minsker DH, Cukierski MA,
months of stopping treatment.
Clark RL, Prahalada S, Antonello JM, MacDonald
JS, Robertson RT (1991). Reversible decreases of
fertility in male Sprague-Dawley rats treated orally
Can I take finasteride while breastfeeding?
with finasteride, a 5-alpha-reductase inhibitor.
Reprod Toxicol. 5: 353-362.
This medication has not been
approved for use by women. Even if a
woman does decide to use finasteride and
breastfeed, there are no studies to show if it
is excreted in breast milk.
July 2005
Copyright OTIS,
Reproduced by permission.