Make your own free website on

Sildenafil - Misconceptions and Facts

by Dr Cedric Nazareth

On the eve of the introduction of sildenafil (better known by its international brand name, Viagra) in India, it could be worthwhile to look at some misconceptions about the drug and to check out the facts:

* Sildenafil is advocated for any person who wants a better sexual performance

Sildenafil is indicated for erectile dysfunction, which is the inability of a male to achieve and maintain an erection for sexual intercourse. Erectile dysfunction may be due to endocrine, vascular and neurological causes, penile diseases and drugs. Advancing age may also contribute to erectile dysfunction. In clinical studies, erectile dysfunction was assessed by the International Index of Erectile Function (IIEF), based on categorical responses to questions about the ability to achieve erections sufficient for sexual intercourse and the maintenance of erections after penetration. So donít start popping those pills if you do not need to!

* Sildenafil increases libido

Sildenafil does not have a direct effect on the libido (sexual drive). Sexual stimulation remains necessary for an erection. A principal mediator of the erectile process is nitric oxide, which is released with stimulation of nerve endings. Nitric oxide increases cyclic GMP levels which produces corporal smooth muscle relaxation and vascular engorgement, resulting in an erection. Sildenafil inhibits the enzyme phosphodiesterase type 5 which is responsible the break down of GMP.

* Sildenafil treats sterility

In a sterile individual, the sperm count is too low for fertilisation of the ovum. Sildenafil has no direct effect on the sperm count and hence does not treat sterility.

* Sildenafil is to be consumed daily, like a tonic

Sildenafil is not a tonic. It is usually administered as a 50 mg dose approximately one hour before sexual activity. However, sildenafil could be taken anywhere from 0.5 to 4 hours before sexual activity. The dose may be reduced to 25 mg or increased to 100 mg, based on effectiveness and tolerability. The maximum dosing frequency is once per day.

* Sildenafil causes heart attacks

Sildenafil has been associated with serious cardiovascular events, including myocardial infarction and sudden cardiac death. It has not been determined that these effects are due to sildenafil, and they could be related to sexual activity in high cardiac risk patients. However, sildenafil is contraindicated in patients on nitrate therapy because of the risk of life-threatening hypotension. Sildenafil should be employed with caution in patients with ischaemic heart disease who are not on nitrates, patients with congestive heart failure and borderline low blood pressure, patients with multidrug antihypertensive therapy and patients taking drugs such as erythromycin and cimetidine which prolong the half-life of sildenafil.

* Sildenafil is useful in women

Sildenafil is advocated for males with erectile dysfunction. Though some studies have shown benefit in women, there are others which have shown no benefit. Thus sildenafil is not advocated for use in women.


September 2000
Pharma Marketing Page.
This article appreared in Pharma Business, September 29, 2000.
All rights reserved

Home - Articles - Trainer's Corner - New Drugs - Food for Thought - Quizzer's Haunt - Other Useful Sites - Opportunities - Search Engines - Contact Us

Your views, experiences & tips can appear on

Click here