Heart to heart talk

Health@Heart
Philip S. Chua, M.D.
Viagra Revisited
How extensively has Viagra been prescribed todate?
Since we first reported on Viagra (Sildenafil Citrate) in the June 18, 1998
issue of the Cebu Daily News, two months after it was introduced in the United
States, more than 25 million prescriptions for Viagra have been written so far by
more than 290,000 physicians in US alone. The overall success rate has been
outstanding, with very few minor and transient side effects and few complications
reported. It has been found to be a safe medication so long as it is taken on the
advice of a physician and taken properly according to the guidelines set by Pfizer,
the manufacturer.
Is this drug only for men who are impotent?
No. Inability to have a sustained erection in man is not caused only by an
organic disease. Psychological factors play a big role in male potency. Those under
the usual stresses in life could develop a certain degree of impotence. Even men
younger than fifty, who were otherwise healthy except for having ED (Erectile
Dysfunction) have been benefited by Viagra in their ability to regain and maintain a
normal potency. About 33% of men over 40 and as many as 15 million men in the
US have erectile dysfunction.
How does Viagra help ?
The physiologic mechanism of male erection involves release of nitric oxide
(NO) in the corpus cavernosum (core of the penile shaft) during sexual stimulation.
NO activates the enzyme guanylate cyclase, which results in the increase level of
cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in
the corpus cavernosum and allowing more inflow of blood to engorge the male
organ, causing erection. Viagra enhances the effect of nitric oxide by inhibiting an
enzyme (PDE5) that degrades cGMP, thus helping maintain a higher level of cGMP
in the corpus cavernosum.
Is Viagra sold over the counter?
No. This is a prescription drug. One needs to see a physician to be
properlyscreened and advised about this medication, since there are possible side
effects and complications.
What is the most serious reported complication of Viagra?
Deaths have been reported, but rather few compared to the volumes of
Viagra taken in the world today. Medically, the incidence of this complication is
considered low, and the drug is deemed safe by the medical community. Some of
these deaths were from natural causes (like heart attack) which could have
happened even without Viagra, since sexual activity in itself has some risk among
those with untreated heart disease. Many of these deaths were found not to be
directly related to Viagra, but rather due to the combination of Viagra and nitrates
(heart medications that open up arteries) or due to misuse or abuse. The Pfizer
warning is very clear and precise: Patients taking any form of nitrates must not take
Viagra. Patients’ failure to heed the guidelines and this warning has caused most of
the deaths.
What are the side effects?
Some persons experience side effects and others do not. The most common
side effects, which are temporary, include any of the following: headache, flushing,
mild gastric distress, nasal congestion, urinary tract infection, mild blurring of
vision, mild dizziness, and skin rash.
Can Viagra cause cancer?
Pfizer reports that Viagra is not carcinogenic in extensive laboratory studies
done on this drug. There is no evidence either that the drug is toxic to embryo, or to
fetus, or that it is teratogenic.
Does Viagra affect fertility or sperm motility?
No, Viagra does not affect fertility or the morphology or motility of sperm.
Does Viagra increase libido?
No, not directly anyway. There must be passion and stimulation between the
partners involved before Viagra works. If there is no mutual attraction and desire,
this drug will not work.
Will Viagra work for females?
The efficacy of Viagra in women is still under scientific investigation in the
United States. There are some good preliminary indications that this same drug
may, in fact, be helpful also to women. The mechanism of action in females is the
same as in males. The “engorgement or erection” is in the clitoris of women. The
final official scientific verdict on this matter will be forthcoming soon.
How long does the effect of Viagra last?
The recommended initial dosage of 50 mg tablet taken orally lasts more than
2 hours in most, and even longer in some men. Erection is sustained until the sex act
is completed, and gradually and normally subsides a few minutes thereafter. Any
annoying distraction or any undesirable incident, before, during or after the sexual
activity, will physiologically discourage erection.
If a man is not taking medications containing Nitrates, is Viagra safe?
Yes, according to scientific literature and medical experience. Taken
properly under a physician’s supervision, Viagra is safe. The person contemplating
to take Viagra must therefore see his physician for a good medical checkup and
advice. Besides, one needs a physician’s prescription to purchase this medication,
which is considered a wonder drug by the medical community.
Any other drugs in the pipeline?
Yes. Vasomax, a form of phentolamine made by Texas-based Zonagen, Inc,
could be taken orally and takes effect within 15 minutes, now being reviewed by the
FDA. Apomorphine is another drug being investigated for its value as a potency
drug.
====================================================== Philip S. Chua, M.D. is the Chairman of Cardiovascular Surgery of the
Cebu Cardiovascular Center of the Cebu Doctors’ Hospital, Cebu City,
Philippines, where he and his team perform open heart surgery. He trained
under the world-renowned heart transplant surgeon, Denton A. Cooley,
M.D., at the Texas Heart Institute in Houston, Texas. He is the President
and Chairman of the Board of the Philippine Heart, Inc. in Munster,
Indiana, U.S.A., where he also practices and does cardiac surgery.

Source: http://www.feu-nrmf.ph/drchua/pdf/V/ViagraPinoywebsite.pdf