The citrate of sildénafil (international non-proprietary name), is a drug developed by the pharmaceutical firm Pfizer, under the Viagra® mark. Initially developed like agent antihypertensor, the results were disappointing. But during the clinical trials, unquestionable patient announced like side effect of the episodes of priapism. The drug is marketed for the dysfunctions of the function érectile (impotence). In the United States it is also marketed under the name of Revatio® for the treatment of pulmonary arterial hypertension
from : www.wikipedia.org
