SILDENAFIL (VIAGRA)

USES:

Treatment of male erectile dysfunction (MED).

Viagra is the first orally available for treatment of this condition.

HISTORY:

1985 Drug discovery programme initiated at Pfizer to develop a treatment for angina. Starting point was to chemically modify a vasodilator Zaprinast which had been developed by May and Baker (now Rhone Poulenc and which is about to merge with Hoechst to become aventis) but it had never reached the market place.

1989 Approximately 1600 compounds were synthesized for this programme including sildenafil.

1990 Sildenafil went into Phase I clinical trials on healthy patients. However, it did not fulfil its expectation for the treatment of coronary disease. Side effects of the drug in men in the clinical trials indicated that it had potential for the treatment of MED

1994 Phase II trials for men suffering from MED

1998 The US Food and Drug Administration approved the use of Viagra for treating MED

Present Each week 1400 Kg of pure sildenafil is made in Ringsakiddy, Ireland. Each batch takes 21 days to prepare by an automated process. The crystalline material is diluted with a cocktail of inactive ingredients at centers in France, Puerto Rico and the US and the powder is coloured blue and formulated into rounded diamond shaped tablets equivalent to 25 mg, 50 mg and 100 mg of sildenafil. Pfizer aims to start production at its plant in Kent for sales in the UK in 2000.

Viagra:

SOME VIAGRA JOKES:

1) In Pharmacology, all drugs have generic names. Tylenol is Acetaminophen; Advil is Ibuprofen, and so on.

The FDA has been looking for a generic name to call Viagra, and today announced they have settled on

Mydixarisin. Also considered were: Mydixadrupin and Mycoxafailin.

2) Q: Did you hear about the man who got a viagra pill stuck in his throat?

A: He died of a stiff neck.

3) An elderly gentleman went to the local drug store and asked the pharmacist for Viagra. The pharmacist said,

"That's no problem. How many do you want?"

The man answered, "Just a few, maybe 4, but cut each one in 4 pieces."

The pharmacist said, "That won't do you any good."

The elderly gentleman said "That's all right. I don't need them for sex anymore as I am over 80 years old. I just

want it to stick out far enough so I don't pee on my shoes."

4) Q: What do Disneyland and Viagra have in common?

A: You wait one hour for a two minute ride!

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