E-drug: Viagra petition to the FDA
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Dear Colleagues;
We petitioned the FDA on July 1, 1998 asking for changes in the labeling
for sildenafil (Viagra), the very popular drug used to treat male erectile
dysfunction. The full text of this petition can be found on our web site
at http://www.citizen.org/hrg. The petition is based on sildenafil
clinical data submitted to the FDA by Pfizer prior to the drug's approval
and on adverse drug reaction reports received by the FDA through June 30,
1998. The petition asks that sildenafil's labeling be amended to reflect
the following:
In all of the large multi-center clinical trials of Viagra, men with
various medical conditions were excluded from the studies. Among those
excluded were people with blood pressures of less than 90/50 or more than
170/100; active peptic ulcer disease or bleeding disorder; any clinically
significant baseline laboratory abnormality, need for anticoagulants,
androgens, or trazodone (an antidepressant); need for aspirin or NSAIDS and
a history of peptic ulcer disease; history of retinitis pigmentosa;
uncontrolled diabetes or diabetic retinopathy; stroke or myocardial
infarction within 6 months, cardiac failure, unstable angina, ECG ischemia
(a common finding in people with coronary artery disease); or
life-threatening arrhythmia within 6 months. For none of these conditions
is there an exclusion in the FDA-approved labeling for sildenafil.
Many commonly used drugs can interfere with sexual function in both men and
women, causing loss of libido, or can interfere with erection or
ejaculation in men, or can delay or prevent orgasm in women. Drug-related
effects on sexual function may be difficult to distinguish from the effects
of depression or disease, but most are reversible when drug use is stopped
and sometimes when dosage is decreased.
The petition contains a list of drugs that are known to cause sexual
dysfunction that was originally prepared by the editors of The Medical Letter on
Drugs and Therapeutics in 1992 We have added new drugs to the
list if there was evidence from published studies that they can cause
sexual dysfunction.
In the first 174 adverse reaction reports received by FDA since Viagra was
marketed and up to June 30, 1998, 75 listed one or more drugs being taken
by the patient in addition to Viagra. Of these 75 reports, the other drugs
were fully listed in 69 of the reports. Of these 69 adverse reaction
reports, 32 (46.4%) included one or more drugs known to cause sexual
dysfunction.
Of the 75 reports in which patients were using one or more drugs in
addition to Viagra, in 27 or 36%, one or more drugs for the treatment of
cardiovascular diseases were used, many of which were probably the diseases
for which people were excluded in the pre-approval clinical trials. Some of
the cardiovascular disease (including diabetes) for which people are taking
these drugs, in addition to Viagra, are themselves associated with an
increased amount of sexual dysfunction. But to worsen pre-existing sexual
dysfunction and then treat this with Viagra, instead of attempting to substitute
another drug less likely to cause sexual dysfunction or to lower
the dose of the offending drug seems to be an unwise medical decision, if
indeed it is being made with full knowledge.
If anyone has difficulty in accessing our web site please e-mail us your
address and we will post a copy of the petition.
Warmest regards,
Larry
Larry D. Sasich, Pharm.D., M.P.H., FASHP
Research Analyst
Public Citizen Health Research Group
1600 20th Street, NW
Washington, DC, USA
Phone: 202-588-7782
FAX: 202-588-7796
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