My column in this paper in 1998 was about Viagra, a headliner around the world then when it was first introduced that year. Two decades next year, Viagra and its competitors, Cialis and Levitra, still arouse interest globally.
Sildenafil (Viagra), the wonder pill for the treatment of erectile dysfunction (ED) in men, was approved by the US Food and Drug Administration in March 27, 1998, and sold like hot cakes that same year. More than $400 million worth was sold in the first quarter, 10,000 prescriptions a day. This blue pill was found to be very effective and safe. It boosts marriages and relationships. The surgical procedures for ED dropped dramatically since this pill was introduced.
Then came the competitors! Vardenafil (Levitra) was approved in September 2003, and on November 21, 2003, Tadalafil (Cialis) was launched. To this day, these 3 pills for ED are the most popular, dominant, and effective regimen in the management of erectile dysfunction and they have been found to also be very useful in enhancing erection even among those without ED. More than 20 percent of failed marriages and broken relationships are due to erectile dysfunction.
While their mode of action are basically the same: they are a class of drugs called PDE-5 inhibitors. They block an enzyme called phosphodiesterase type 5, boosting a chemical in our body called nitric oxide, which relaxes muscles in the penis and open up veins, allowing more blood to enter and fill-up the veins of the penis, causing engorgement and maintaining erection.
Original Research: Serendipity
The original laboratory studies on these PE-5 inhibitors centered on their vasodilator effects as potential drug in the management of coronary heart disease and high blood pressure. However, the researchers noted that the experimental male mice given the PDE-5 inhibitor developed erection and were chasing the female mice. This serendipity discovery that the side-effect of the PDE-5 inhibitor was even a greater and more welcome discovery than the original intention of developing a new vasodilator for cardiovascular diseases. The side-effect (erection) in this case far outweighed the “original intent” for the use of the drug. This is one incident where the side-effect is more useful and beneficial.
These pills for ED (PDE-5 inhibitors) are also prescribed for other medical conditions, like heart attack, pulmonary hypertension (even among children), pre-eclampsia, Crohn’s disease, and infertility.
Some think Viagra, Cialis, and Levitra are aphrodisiacs. No, they are not, because none of them increases libido (sexual desire). These 3 only enhance erection and sustain it for a successful sex. When taken, the man develops a sense of certainty, security, and confidence, which could incidentally increase the desire in both partners.
Indications for use
Those who could benefit from any of these 3 PDE-5 inhibitors are those who are unable to initiate and maintain erection for a successful intercourse, regardless of age, including those in their 20s, where stress and psychological condition negatively impact their sex life. One does not have to have a full-blown erectile dysfunction to benefit from these pills, since they have been found effective and save since they were introduced almost 20 years ago.
Cleveland Clinic reports that 52 percent of men have erectile dysfunction, “affecting 40 percent of men age 40, and 70 percent of men age 70.” Men who are on high blood pressure pills, beta-blockers, etc., have an increased risk of developing ED. Urology Care Foundation says 30 million of American males have occasional (mild to moderate) problem getting or keeping an erection.
These three drugs for ED belong to one class of medication and have similar pharmacologic action: PDE-5 inhibitors. All three react with nitrates (heart medications that opens up arteries), which could cause drop in blood pressure and shock, even death. Those on nitrates MUST not take any of these drug for ED. These three are in oral form and there is no generic version of this ED drug yet, and is taken about 30 before anticipated sex. Any of these 3 needs medical consultation prior to use to rule out any contraindication and danger, since each individual reacts differently to medications. A prescription is needed to purchase pills for ED. They all cost about the same. Their safety records are also similar.
While their action, use, and efficacy are basically the same, there are difference among these three pills for ED. Viagra and Levitra stay in the blood stream for about 4-6 hours; Cialis, 17-18 hours, longer lasting. Other differences are in their side-effects.
The following side-effects are common among all three: stuffy nose, headache, upset stomach, priapism (erection, painful, that persists), sudden cardiac arrest, death (which are very rare). The differences: temporary change in vision and flushing are more in Viagra and Levitra. Backpain and muscle aches are more with Cialis. Alcoholic beverage reacts more with Cialis, leading to dizziness, less with Viagra and Levitra. But, as Shakespeare wrote: “Alcohol increases the desire but diminishes the performance.”
Any of these three drugs for ED dangerously reacts with nitrates, medications that dilate (open up) coronary arteries used in the management of coronary heart disease. A person on a nitrate medication (like nitroglycerin, isordil, imdur, peritrate, nitrostat, nitroderm, nitrolingual, nitrobid, etc.) must NEVER take any of these three pills for ED, because the combination will lead to severe drop in blood pressure, shock, and possibly death. Consult your physician if erection does not subside in 4 hours, a condition called priapism, where the penis is so engorged causing pain, one that needs urgent medical care.
The reported deaths associated with the use of any of these three pills for ED were suspected to be due to the inadvertent concomitant use of nitrates. New studies have shown that these PDE-5 inhibitors could also increase platelet clumping in diseased coronary arteries causing blood clots, and heart attack in some individuals.
"It's reassuring that ... in general, for most patients, even those with existing coronary [heart] disease ... resuming sexual activity is very unlikely to trigger a [coronary] event," according to Murray A. Mittleman, MD, researcher and cardiologist at Beth Israel Deaconess Medical Center in Boston.
All evidence-based clinical information around the world today show that these three PDE-5 inhibitors are efficacious and safe, when used according to standard medical recommendation and under the supervision of an attending physician.