Evaluating phosphodiesterase type 5 inhibitors in the treatment of erectile dysfunction

This study reviewed the effectiveness and safety of phosphodiesterase type 5 inhibitors (PD5I) to treat men with erectile dysfunction. Researchers suggested that PD5I therapy improves the treatment outcomes of these patients.   

Erectile dysfunction affects around 50% of men between 40 and 70 years. It consists of the inability to get or keep an erection firm enough to have sex. It usually has a physical cause such as disease, injury, or side effects of drugs. An erection occurs when blood flows into the penis increases, making the penis larger and firmer. An event that disrupts this will prevent an erection from happening. 

PD5I are the recommended first-line treatments. These drugs dilate the area of the penis where the blood flows, resulting in an erection. Sildenafil citrate (Viagra) was the first PP5I to be used, followed by vardenafil (Levitra), tadalafil (Cialis), and avanafil (Stendra). These drugs are available in most countries worldwide. While other PD5I such as udenafil (Zydena) and mirodenafil (Mvix) are approved in Korea and lodenafil (Helleva) is only approved in Brazil. 

Prior studies suggested that PD5Is are effective and safe in more than 80% of patients. However, the dropout ratio is still very high (30-70%). This is especially due to treatment failure and side effects. Studies comparing the different PD5I are limited and are still unclear in which drug is the safest.

This study reviewed 184 other studies with information about 50,620 patients with erectile dysfunction. The use of PD5i was compared with placebo and with other PD5Is.

All PP5I were associated with improved outcomes when compared to placebo. Sildenafil 25 mg was the safest drug and with better effectiveness. This was followed by sildenafil 50 mg. Taladafil 10 and 20 mg also presented good profiles. While avanafil and Iodenafil were associated with poorer effectiveness.

Mirodenafil 150 mg was the drug that caused the most side effects, such as headaches. Sildenafil 100 mg caused more visual disorders, while vardenafil and udenafil were associated with nose congestion.

This study concluded that sildenafil at low doses (25 mg or 50 mg) and tadalafil (10 mg or 20 mg) should be the first treatment option for erectile dysfunction.