Abstract

THE EFFECT OF HALF-LIFE & SELECTIVITY OF PDE-5 INHIBITERS ON BLOOD HOMEOSTASIS

Shatha H Ali (PhD), Adnan Mohsen and Dr. Adnan Al-Zubadi

Abstract

Elevation of erectile dysfunction percentage with increasing age and existing of different disease such as diabetes mellitus, depression, hypercholesterolemia, ischemic cardiac disease, hypertension and obesity. Develops in clinical research in ED through previous15 years, resulted in advance of several modern treatment options, including pharmacological agents for intraurethral, intracavernousal, also recently, oral Phosphodiesterase type-5 inhibitors (PDE5-i). A phosphodiesterase type 5 inhibitor (PDE5 inhibitor): Sildenafil, tadalafil, vardenafil, and the newer types are selectively inhibit PDE5, is a drug used to block the degenradative action of cGMP-specific phosphodiesterase type 5 (PDE5) on cyclic GMP in the smooth muscle cells lining the blood vessels supplying the corpus cavernosum of the penis. This study is aimed to investigate the effect of half-life and PDE-5 selectivity on biochemical changes that occur during administration of PDE-5 inhibitors (Sildanafile or Tadalafile) on some hematological parameters especially Bleeding Time (IVY), fibrinogen weight, D-dimer and its titer as compared to the control. This study included seventy male patients with erectile dysfunction. In addition to 70 control subjects .All the participants were with range of age (20-50 years) and apparently had no other diseases .Thirty- eight subjects with erectile dysfunction ED were treated with Sildenafile tablet of 100 mg., and thirty-two subjects with ED treated with Tadalafile tablet of 20 mg. Venous blood specimens were utilized to perform hematological analysis. Results revealed that Sildenafil produced significant alterations in Bleeding Time (IVY), fibrinogen weight, D-Dimer values and its titer after 6 weeks of starting treatment. Whereas, tadalafil produced more pronounced alterations after 4 weeks of treatment on the same parameters. As conclusions; PDE-5 inhibitors (silenafil & tadalafil) enhance coagulation mechanism and thrombus formation. Sildenafil have less effects because of shorter half-life and low selectivity than that produced by tadalafil when used for the same duration of time.

Keywords: PDE-5 inhibitors, Sildenafil, Tadalafil, Bleeding Time (IVY), Fibrinogen, Ddimer, Titer of D-dimer.