The two companies already have agreements to jointly market several drugs, including Levitra, an anti-impotence drug that was developed by Bayer and is expected to rival Viagra when it is released next year.

Many foreign Web sites promote Viagra, the anti-impotence drug made by Pfizer.

Pfizer is expected to market an anti-impotence drug in the near future based on research in that field.

He saw a urologist, who prescribed an injectable, anti-impotence drug.

The German pharmaceuticals company Bayer said the Food and Drug Administration had asked for more studies of the anti-impotence drug it is developing to compete with Viagra from Pfizer.

The State Drug Administration in China approved domestic sales of Viagra, the anti-impotence drug.

The next day, Jordanian authorities approved Pfizer's anti-impotence drug, Viagra, for sale in the country.

The Pennsylvania study found 86 Web sites that sold Viagra, the anti-impotence drug, without requiring a doctor's visit or a prescription.

The anti-impotence drug is illegal there but when smuggled in can bring up to $80 per pill.

Bayer has much of its hopes for improved performance pinned on Levitra, the anti-impotence drug that recently won approval in the European Union.