Commonly known by its brand name Viagra, a drug used in the treatment of impotence. Because of the risk of potentially serious side effects in certain people, the drug must only be used on medical advice.
n. a drug administered orally for the treatment of erectile dysfunction. By inhibiting the action of the enzyme phosphodiesterase type 5, it elevates local *nitric oxide levels, causing smooth muscle relaxation and increased blood flow to the corpus cavernosum of the penis, which results in erection during sexual stimulation. Sildenafil is also licensed for the treatment of pulmonary hypertension. Side-effects include headache, facial flushing, dyspepsia, nasal congestion, and dizziness. Because of severe adverse reactions, the drug is contraindicated in patients taking nitrate-based drugs, such as *glyceryl trinitrate. Tadalafil and vardenafil are drugs with similar actions and effects.
An oral drug – better known to the public as Viagra® – for treating erectile dysfunction of the PENIS (see also ERECTION; SEXUAL DYSFUNCTION). Sildena?l citrate was originally developed to treat ANGINA PECTORIS; during clinical trials, patients reported that they were having more erections than before taking the drug. Clinical trials were then conducted on 4,000 men, and 70 per cent of them found sildena?l e?ective. The men, of an average age of 55 years, had experienced erectile problems for around ?ve years before taking part in the trials. The medical conditions associated with their problems included high blood pressure, high concentrations of CHOLESTEROL, DIABETES MELLITUS, surgery and psychological disorders. Among side-effects, headache was the most common; others included facial ?ushing, indigestion and a stu?y nose. The drug is a vasodilator so that blood ?ow to the penis is enhanced. It works in response to sexual stimulation and has no properties as an aphrodisiac; nor does it provoke sexual fantasies. Sildena?l must not be taken with drugs containing nitrates such as GLYCERYL TRINITRATE or isosorbide trinitrate as the subject may suffer a sudden fall in blood pressure. Nitrates inhaled for recreational use (poppers) have a similar e?ect. Recent research suggests that the drug may help women with low LIBIDO or who have di?culty in achieving ORGASM.... sildenafil citrate
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