Viagra attracts £338m in six months

The anti-impotence drug is widely prescribed in the US

Global sales of Viagra are expected to be huge following the release of sales figures for the anti-impotence drug's first six months on the market.

Most of the sales come from the US because governments around the world have only just granted licences for the drug.

In the UK, the Department of Health has placed a temporary ban on NHS prescriptions of Viagra.

Draining resources

Health ministers fear that demand for the drug could drain the NHS of resources, so they have commissioned the Standing Medical Advisory Committee to produce recommend how the drug should be used.

The demand in the US, where Viagra is widely available, justifies such fears.

Pfizer is expected to make huge profits from the drug

Americans have spent £322m on the drug in six months. Sales in the rest of the world amount to £16m.

The US drugs group Pfizer, which invented the treatment at its research centre in Kent, said Viagra was the most successful prescription drug ever launched in America.

A total of 200,000 physicians have written more than five million prescriptions for three million patients.

European use

Viagra was licensed for use in European Union countries last month, and the Standing Medical Advisory Committee is expected to report to health ministers by the end of October.

Pfizer started promoting the drug - which will cost the NHS £4.84 for each 50mg dose - to British GPs on Monday.

It said that training sales representatives had been difficult because the pre-launch publicity for the treatment had mixed fact with fiction.

The company expects Viagra will cost the NHS £50m annually in five years time.

But it also believes that use of the drug will save the NHS money in the long term because it will encourage men suffering impotence to report the condition.

Andy Burrowes, who is responsible for marketing at Pfizer in the UK, said that impotence was often caused by other conditions such as heart disease or diabetes, which a patient may not realise they have.

If men were happier to come forward to report impotence, he said, doctors would discover the underlying conditions.

"Doctors will be able to get the conditions under control, which will provide savings and benefits in the long run."