A fast-acting rival to the anti-impotence pill Viagra has been approved for sale in Europe.
Uprima is the first alternative to Viagra to reach the marketplace, says Laureen Cassidy of manufacturer Abbott Laboratories in Illinois, US. The small tablets dissolve under the tongue and take about 20 minutes to have an effect.
Viagra, which is swallowed, takes up to an hour to work, and is affected by how much food is in the stomach. "Uprima is so fast because of the delivery form," says Cassidy. "It bypasses the gastrointestinal tract and gets straight into the bloodstream."
Uprima also works in a different way to Viagra. This means that some patients for whom Viagra doesn't work may benefit by taking Uprima.
Viagra works by inhibiting an enzyme called phosphodiesterase. This relaxes the penis and allows increased blood flow, causing an erection. Uprima stimulates dopamine receptors in the brain, mimicking the signal normally sent from the brain to the penis during sexual stimulation. This starts a chain of events in the body that leads to an erection. According to Abbott Laboratories it is effective in about 90 per cent of cases.
Uprima will be available this week in the Netherlands, and in certain other European countries later in June. The drug has not yet been approved for sale in the US.
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1200 GMT, 1 June 2001