E-DRUG: Sildenafil (Viagra) Labeling Updates
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T98-83 November 24, 1998
Pfizer Updates Viagra Labeling
The U.S. FDA and Pfizer Inc. are advising doctors about new warnings and
information in the product labeling for Viagra (sildenafil) in response
to postmarketing reports of serious adverse events. The new information
augments the original drug labeling which warned against the concomitant
use of Viagra and nitrates.
Revised in consultation with FDA, the new labeling is intended to help
make sure that consumers and doctors are fully informed about the
benefits and risks of using Viagra, know that consideration must be
given to the cardiovascular status of patients prior to prescribing
Viagra, and know how to safely use the drug.
As with all approved drugs, there have been postmarketing reports of
important side effects with Viagra. These have been reviewed carefully
by FDA since Viagra's approval in April l998. Although a causal
relationship cannot be established from these reports, they are being
mentioned in the labeling. FDA typically requires manufacturers to
update their labeling with such information. It is important to note
that the postmarketing reports involving Viagra constitute only a small
fraction of the more than six million prescriptions written for this
drug. FDA continues to believe Viagra is safe and effective if used
according to the updated labeling.
The company is providing the updated information about the serious
postmarketing events in a letter to health professionals.
The labeling notes that it is not possible at present to determine
whether the cardiovascular events are directly related to Viagra, to
sexual activity, to the patient's underlying disease, or to a
combination of these factors.
Information added to the labeling includes:
� Postmarketing cardiovascular events: The revised labeling addresses
postmarketing reports of heart attacks, sudden cardiac deaths, and
hypertension.
� Risk of sexual activity: Sexual activity in patients with preexisting
cardiovascular disease carries a potential cardiac risk. Pfizer,
therefore, advises doctors that treatments for impotence, including
Viagra, generally should not be used in men for whom sexual activity is
inadvisable because of their underlying cardiovascular status.
� Vasodilatory effects (effects on blood pressure): Physicians should
consider whether their patients with heart disease could be affected by
transient decreases in blood pressure, especially in combination with
sexual activity.
� Patients who were not studied in clinical trials: Several groups of
patients were not studied in the clinical trials for Viagra. The new
labeling notes that if Viagra is prescribed for these patients, it
should be done with caution. These include patients who:
- suffered a heart attack, stroke, or life-threatening arrhythmia within
the previous six months,
- had significant hypotension (lowered blood pressure) or hypertension
(uncontrolled high blood pressure of greater than 170/110),
- had a history of cardiac failure or coronary artery disease causing
unstable angina, and
- had retinitis pigmentosa, an eye disorder.
� Prolonged erections or priapism: The labeling now includes a warning
about the rare occurrence of painful, prolonged erections. This is a
serious condition that requires immediate medical attention. The
labeling advises patients to seek prompt medical attention if their
erection last longer than four hours.
Health care professionals are encouraged to report any unexpected
adverse or serious events associated with the use of Viagra (sildenafil)
directly to Pfizer Inc. at 1-800-438-1985 or to the FDA MedWatch program
at 1-800-FDA-1088, by fax at 1-800-FDA-0178, or by mail (MedWatch, HF2,
FDA, 5600 Fishers Lane, Rockville, MD 20857).
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