Erectile dysfunction medication
There are a number of different types of medication that are prescribed to treat erectile dysfunction. These include:
Sildenafil (Viagra, Avigra, Dynafil, Revatio, Videna, Sildenafil Cipla)
The oral drug sildenafil, sold under the trade name Viagra, has been a media sensation. The diamond-shaped blue tablet is taken about 60 minutes before sexual activity.
Sildenafil works by inhibiting an enzyme called 5-phosphodiesterase, thus increasing the levels of a substance called cyclic GMP. It is a powerful dilator of blood vessels in the penis, leading to the inflow of blood and an erection under stimulating circumstances.
There have been reports of Viagra users dying from heart attacks, but these attacks were not thought to be related to the drug. A certain percentage of heart attacks will occur during strenuous activity. Nevertheless, the manufacturers have issued warnings to individuals with cardiovascular disease.
Caution is specifically advised for groups for which the drug has not yet been studied, such as men who've had a heart attack, stroke or life-threatening arrhythmia in the past six months, those with significant hypotension (low blood pressure) or hypertension (high blood pressure), those with unstable angina and those with retinitis pigmentosa, a disease that causes retinal deterioration. The only current absolute contra-indication is the concomitant use of nitrate-containing cardiovascular medication.
Nitrates such as Glyceryl tri nitrate (GTN) or isosorbidemononitrate are usually prescribed for ischaemic heart disease and angina.
Viagra has also become popular for recreational use, for example in night-clubs. However, it is a prescription drug that should only be taken under medical supervision.
Experts say that it does not have benefits for men who have normal erections. It can be lethal when used in conjunction with inhaled amyl nitrate (“poppers”), a recreational drug particularly popular among gay men.
It is used to create a “rush” of sexual stimulation, but in the process also causes blood pressure to plummet to levels that may be dangerously low. This also applies to Viagra use in conjunction with heart medications that contain nitrate.
Viagra costs between R70 and R100 a tablet, depending on its strength, but generic forms of the drug are now also available.
Following the phenomenal success of Viagra, several other drug companies have launched similar type of drugs. These include Vardenafil and Tadalafil.
Vardenafil or Levitra, like Viagra, is a phosphodiesterase type-5 inhibitor and was developed specifically for erectile dysfunction as an oral agent. Multiple trials have shown that Levitra is effective in improving the rate of achieving and maintaining an erection during sexual intercourse. An improvement in other aspects of sexual function was also noted, including confidence, orgasmic function and overall satisfaction.
Vardenafil produces significant improvements in erectile dysfunction regardless of age, baseline severity and cause of erectile dysfunction. It is also sometimes effective in patients with diabetes and after radical prostatectomy surgery for prostate cancer. Levitra has a rapid onset of action and sexual intercourse is possible as early as 16 minutes after swallowing it.
Levitra is well tolerated with side effects very similar to that of Viagra. The most common side effects are headache, flushing, rhinitis (stuffy nose) and indigestion (heartburn), which are mild or moderate and generally decrease with continued treatment.
Levitra comes in two dosages namely ten and twenty milligrams. Ten milligrams is more than adequate for mild to moderate erectile dysfunction. It is also now available in a 10mg oro-dispersable, quick acting format called Levitra 10mg ODT.
Tadalafil (Cialis, Ciavor)
Tadalafil is another drug used to treat erectile dysfunction. It has been dubbed the weekend drug for its long duration – up to 36 hours in some patients. This is because the chemical structure is different to the other two PDE-5 inhibitors. It has been demonstrated to be effective for most causes of erectile dysfunction.
Side effects, although similar to the other two PDE-5 inhibitors, have the addition of back pain that appear to be self limiting, mild and benign. Cialis is also contra-indicated with nitro-glycerine or any nitrate medications because of a drop in blood pressure.
A low dosage concentration of Cialis (5mg) is now available for daily use. Although expensive (more than R800) it might be advantageous to regain erectile function after radical prostatectomy.
It should be noted that all three companies manufacturing Viagra, Levitra and Cialis published a disclaimer in 2008. They stated that several cases of sudden hearing loss were reported with these drugs. It does not appear to be a major problem, however.
More on medication
- Other drugs claim to be effective, but have not been proven to be so in scientific studies. These include yohimbine hydrochloride, dopamine and serotonin agonists, as well as trazodone. These drugs are often mixed with alprostadil (a prostaglandin), to achieve better results.
- Medications may be used in conjunction with counselling, psychotherapy or psychiatric medication if erectile problems have psychological causes.
Reviewed by Dr Dave Bowden MBBCh (Wits), FCS (SA) Urol. Specialist Urologist in private practice, Christiaan Barnard Memorial Hospital, Cape Town. (February 2015)