Viagra is giving older men a new lease on sex - but many wives are upset about it.
A $600,000 study paid for by the Health Research Council (N Zealand) has found that many women blame doctors for giving their husbands the erection-producing drug without considering its effects on them.
They say men's clinics use the health drug as a quick-fix for men instead of helping couples with other problems in their relationship or simply accepting that older people do not need sex as often.
The study is based on interviews with 27 women with an average age of 53, and 33 men, who responded to advertisements throughout the country in 2001. It is believed to be the world's first publicly funded research project on the social effects of the drug.
Viagra manufacturer Pfizer says more than 15 million people around the world have taken the drug since it was released in 1998, despite a price which is now around $100 for a packet of four pills. Each pill can have an effect for up to 12 hours.
Lead researcher Dr Annie Potts, a research fellow in gender studies at Canterbury University at the time, said about a quarter of the women came forward because they wanted to talk about the detrimental effects of the drug.
The other three-quarters, who often said the drug had allowed them to have sex again, included many who personally 'don't necessarily want sex as much as they are getting now'.
'Even women who had a generally positive narrative about Viagra explained that a 'downside' or 'drawback' could be an undesired increased frequency of intercourse, because of pressures coming from the desire not to waste a tablet,' the study says.
A 51-year-old woman told the researchers that she sometimes felt pressure to have sex both at night and the next morning so that her husband could 'get in two for the price of one'.
A 48-year-old said: 'It had such a powerful effect that ... this made sex inevitable. Sometimes there was no discussion about whether ... the sex act was going to take place, so it would be ... 'I've taken the pill, okay's, let's go.' '
She commented: 'It took away the whole notion of any kind of ... spontaneity or you know, the reason for the actual boning. I mean, you know, you like to think it's an act of love, rather than just lust.'
Some older women were in pain during sex because of post-menopausal vaginal dryness, even when they used lubricants.
Another 51-year-old said she consented to sex even when she was in pain because she had heard that older men needed to keep having it or they might 'lose the art'.
Some feared that Viagra would drive their partners to other women. Five of the 33 men confirmed that they had been unfaithful since taking the drug.
The study concluded that women as well as men should take part in doctors' consultations and decisions about erectile problems.
'Men talked about how easy it was to get the drug. Even men who were not experiencing erectile problems found it was easy to go in and get the drug,' Dr Potts said.
A 60-year-old woman told the researchers: 'We weren't interviewed together ... because they seem to have this idea that this is a man's problem. But it's not a man's problem, it's a couple's problem, and how the woman feels about it should come into it too.'
Other women complained about doctors' 'clinical coldness'. But the head of the Medical Association's General Practitioners' Council, Hawks Bay GP Peter Foley, said that when male patients asked for Viagra, doctors could not force them to talk to their partners first.