Yesterday, Pfizer announced that results from the first stage of a large-scale, post-marketing study of Viagra (sildenafil citrate) in men with erectile dysfunction (ED) confirmed the safety profile established by the extensive clinical trials program.
The independently-conducted observational study of 5,391 men in the UK
found no evidence of increased risk of heart attack or death from ischemic
heart disease. The data were comparable to UK national health data of the
general population of men of the same age. Men in the study had been
prescribed Viagra in the general practice setting and had been taking the
medicine for an average of five months. Among physicians who provided an
opinion on effectiveness, Viagra was reported to be effective in 85 percent of
patients. The study did not identify any safety issues.
"With availability of Viagra now having passed the two-year mark, this
study provides important confirmation that Viagra has an excellent safety
profile and is well tolerated in the wide variety of men who suffer from ED,"
said Joe Feczko, M.D., Senior Vice President for Medical and Regulatory
Operations for the Pfizer Pharmaceuticals Group (PPG).
Among the men taking Viagra in the study, the combined incidence of fatal
and non-fatal heart attacks was 7.2 per 1000 person-years and incidence of
mortality due to ischemic heart disease was 3.2 per 1000 person-years. The
mean age of men in the study was 57 years (range 18-89); sixty four percent of
men studied were between the ages of 50 and 69. The study found that when
compared to UK national health data, the incidence of these findings were
similar to that occurring in the general population of men of the same age.
In addition, the study also found there were no cases of heart attack, stroke
or death reported during the first month after treatment was prescribed.
"Our interim results are reassuring and did not produce any surprises,"
said Saad Shakir, FACP, FFPM, MRCGP, Director of the Drug Safety Research Unit
(DSRU) at Southampton University, UK, who recently presented the interim
results of the study at the annual meeting of the European Society of
Pharmacovigilance, in Verona, Italy.
These findings are consistent with data used to support
the approval of Viagra worldwide. The database of clinical trials currently
includes 36 double-blind placebo-controlled trials, including 4,500 men taking
Viagra and over 3,000 men taking placebo. The trials involved men of
different ages, backgrounds and health status, including men with pre-existing
Viagra is is Pfizer's treatment for erectile dysfunction that was approved by the U.S. Food and Drug Administration in March 1998 and by the European Commission in September 1998.
The medicine has since been approved by regulatory authorities in over 100
countries around the world. Over 25 million prescriptions have been written for Viagra for over 10 million men. More than 300 million tablets have been dispensed worldwide.
Viagra is a prescription medication available only from doctors and should always be used in accordance with its approved labeling. Viagra is
contraindicated in patients who use nitrates. The most common side effects of
Viagra are headaches, facial flushing and indigestion.