A leading Israeli rabbi has ruled that the anti-impotency pill Viagra can be taken by Jews on Passover, reversing a previous ban.

Viagra had been deemed not kosher since 1998 under strict dietary laws over the week-long Jewish spring holiday.

Rabbi Mordechai Eliahu said the pill can be swallowed if it is encased in a special soluble kosher capsule first.

Viagra's Israeli manufacturers said they sought an answer after receiving queries from worried religious men.

Forbidden foods

The drug was previously prohibited because its coating was considered inedible over Passover, when contact with everyday ingredients, known as hametz, is forbidden under Jewish law.

In particular, Jews must dispose of any foodstuffs containing leavening agents, such as bread, cake or biscuits, or anything which might have come into contact with them in the production process.

The dietary laws are so strict that only drugs to treat life-threatening conditions may be consumed during the festival, which lasts for seven days in Israel and eight days for Jews in the rest of the world.

According to the Jerusalem Post newspaper, Rabbi Eliahu, a former chief rabbi, said men can take Viagra if they purchase special capsules made from kosher gelatin in which to put the pill before the holiday starts.

Viagra's Israeli manufacturer, Pfizer Pharmaceuticals-Israel, said swallowing the capsule does not breach Jewish law because the Viagra would not come into direct contact with the body.

A prescription for Viagra is issued in Israel on average once every minute, the newspaper reports.

Since Viagra was introduced seven years ago, more than 23 million men have been prescribed the drug worldwide, Pfizer says. Annual sales are worth nearly $2bn.