The wave of joy unleashed by the little blue pills has not stopped there. Investors have watched the share price of Viagra's manufacturer, Pfizer, respond like the organ at which it is targeted, almost doubling in price to around $120 (pounds 70).
It has been claimed to be the fastest-selling drug in history, to have ushered in a sexual revolution as great as that produced in the Sixties by the contraceptive Pill, and to have "smashed the citadels of American puritanism" by opening up discussion of erections, orgasms and oral sex on the airwaves. As the Independent's former US correspondent, John Carlin, noted: "Americans have learnt to talk dirty."
Not only Americans. In Spain almost every magazine has put Viagra on its cover. The influential El Pais newspaper devoted its Sunday colour supplement to the pill, promising "a new golden age of sexuality". Spanish men are reported to be thronging the pharmacies of Andorra and Gibraltar, where the drug is freely available - at a price. Andorra ran out a week after packets went on sale early in May at up to 87,000 pesetas (nearly pounds 350) for 30 pills. Commentators have observed that the Viagra phenomenon has tapped into the growing insecurity of the Spanish male, his self-esteem humbled and diminished over 20 years as Spanish women's independence has blossomed.
Public reaction in France has been more muted - a mixture of amusement and curiosity. The French press was among the first to warn of the drug's potential risks for heart patients, and the French health minister, Bernard Kouchner, announced yesterday that he was calling a conference of experts to discuss its benefits and possible risks.
German health funds are worried that Viagra will bankrupt the system. It has been calculated that if every male of appropriate age takes eight Viagras a month, the total cost of increased sexual performance would be 10bn German marks to the health service.
Just how great a revolution Viagra heralds is in some doubt, however. A black market has sprung up as the first worries about side effects have emerged - the pill gives some men blue vision and, more seriously, is being investigated for its links with six heart-attack deaths in the US - and it is already being used to justify dubious sexual behaviour.
Jerry Springer, the US talk-show host, blamed Viagra when he was caught frolicking with a 21-year-old porn star, Kendra Jade, shortly before she appeared on his show. "That Viagra made me lose my mind. I thought I was some kind of sexual superman," he said.
Critics say it has provided not the lesson (learnt with the advent of Aids) but the licence to talk dirty in a culture that has become over- sexualised, overdemanding and where millions have been made to feel that without the drug they may be missing out.
Viagra, whose chemical name is sildenafil, works by blocking an enzyme called phosphodiesterase which causes erections to subside. It was discovered by British researchers testing it as a treatment for heart disease on student volunteers who noticed it had a pleasing side effect.
Journalists, normally guarded about their sex lives, have shown an uncommon readiness to share the secrets of the bedroom with their readers in return for a chance to try it. The Sun gave it to New York-based reporter Drew Mackenzie, 47, and his wife Emily, 39, and printed their separate accounts of the experience under the headline "My night testing miracle sex pill." Mr Mackenzie duly reported how the pill re-introduced him to his 18-year- old self, while Emily confided: "Just between you and me, girls, it did make him feel a different man."
In the Daily Mirror, Anne Williams, 37, described how she decided to try it for herself. One night and multiple orgasms later, after dispatching her weary partner to work, she wrote: "Once Viagra kicks in, your only interest in pleasure. Having an orgasm - or three - is easy."
With this kind of publicity, a black market in the drug was inevitable. A licence is not expected to be granted in Britain before the autumn but British men - and women - have been obtaining it by mail order via the Internet from sources in the US which are less than scrupulous about checking medical histories. Charges are around pounds 15 a pill plus pounds 50 for the "consultation". Pfizer is in discussion with the health department over what can be done to curb these unauthorised sales.
Private clinics in London and elsewhere are also falling over themselves to offer the drug, which they can do legally, in advance of its receiving a UK licence, on a "named patient" basis. This means they must keep a record of every patient to whom they prescribe it and take special care over examining and treating them. However, reports are already emerging of patients with no impotence problems obtaining the pills from some clinics with a minimum of checks.
A spokeswoman for Pfizer deplored the recreational use of the drug. She said: "This is a serious treatment for a serious disorder. It is not something that should be trivialised."
What accounts for Viagra's success? It is not the first treatment for impotence, but it is the first to be made available in pill form. Nor does it produce an instant erection, as the injectable treatments do, but responds only to psychological and physical stimulation. It has to be taken an hour before sex but a faster-acting version is being worked on. The launch of a new drug tends to follow a roller coaster pattern. First there is euphoria as doctors enthuse about it and patients turn up in droves demanding it. Then the first side effects appear (as has just occurred with Viagra) and there is a slump in enthusiasm as people start to ask whether the risks outweigh the benefits. Finally, when the scares subside, prescriptions rise gently to a lower but sustainable level as doctors learn which patients can genuinely, and safely, benefit.
In Viagra's case, this roller coaster ride looks like being exceptionally swift. With prescriptions in the US, where the drug is licensed, running at 100,000 a week little more than a month after its launch, the first setback came last week. The Food and Drugs Administration announced that it was investigating six deaths from heart attack among men who had been using Viagra. The company's share price instantly drooped.
It is unclear whether the men died because of an interaction between Viagra and the medication they were taking for heart problems or whether the effort involved in unaccustomed sexual activity was enough to trigger an attack. A spokeswoman for Pfizer said yesterday that information leaflets issued with the drug warn it should not be taken in combination with any heart treatment containing nitrates. "This was well known to the FDA and should be known to the physicians prescribing it," she said.
However great the care in prescribing, further deaths cannot be ruled out. The causes of impotence are varied but they include diabetes, prostate and bowel problems and mainly affect older men. In other words, they are people who are already vulnerable and in some there may be hidden heart disease. No human activity is free from risk - especially one engaged in by a man of 70 who has been made to feel as if he's 20 again. Leading article, page 18Reuse content