Background to Erectile Dysfunction

As the recorded incidence goes, launch of Viagra in 1998 increased awareness of erectile dysfunction.

Prior to the introduction of the first oral medication to treat this common affliction associated with the aging process, most men simply had to suffer in silence with the sort of resignation they applied to balding or sagging skin.

Erectile dysfunction (ED) is now known to be primarily organic in nature, resulting from vascular, hormonal or neurological complications.

In addition, ED can be a marker for other pathological conditions or undiagnosed organic diseases. On top of the physical symptoms, it significantly reduces quality of life along with depression and loss of self confidence.

Treatments of Erectile Dysfunction

These days, the first line of treatment of ED is oral medication. There are three oral medications available on the market, all of which are PDE-5 inhibitors. These are administered by the patient shortly before sexual activity. Patients can also bring some change to their lifestyle (such as losing weight) to improve erectile quality.

Doctors and patients face a unique dilemma these days. All three oral medications (Viagra, Cialis and Levitra) with different molecular structures and pharmacokinetic properties variable have similar success rates. Apart from this, all three medications are rapidly absorbed from the gastrointestinal tract. Viagra and Levitra reach peak plasma concentrations within one hour and Cialis reaches the same by 2 hours.

Treatment Characteristics

Food, in particular fatty foods, appears to inhibit both Viagra and Levitra but not Cialis when compared with the fasted state.

When taken with food, peak plasma concentrations of Viagra are reduced by 30% and the maximum concentration is delayed by one hour. Food also delays the maximum plasma concentration of Levitra by one hour, with a 20% reduction compared with the fasted state. The pharmacokinetics of each of the drugs is not affected by alcohol consumption although there is a causal link between alcohol consumption and erectile dysfunction. In any case, alcohol should be avoided by patients during ED treatment.

Viagra and Levitra both have a terminal half life of approximately 4 hours and for Cialis it is approximately 17.5 hours. None of the drugs have an immediate onset.

Most studies have demonstrated that the drugs have an onset action of between 30 and 60 minutes but the rate of onset varies between individuals.

The PDE-5 inhibitors showed marked differences in their duration of effect. Viagra and Levitra showed 4-5 hours duration of effect while Cialis, consistent with its longer half life, showed up to 36 hours of duration of effect and thereby providing patients with a broad window of responsiveness.

Comparative Studies between Cialis, Viagra, Levitra

Although comparative studies have been conducted to examine the relative effectiveness of each of the drugs, most of the studies eliminated patients who did not respond to Viagra. This can seriously undermine the value of the data produced.

Page 1 of 2 :: First | Last :: Prev | 1 2 | Next