During the past decade, the effectiveness of peripheral
vasodilator drugs in the treatment of chronic occlusive arterial disease has been questioned.
Pentoxifylline is a hemorheologic agent with primary actions that include increasing erythrocyte flexibility, reducing blood viscosity and increasing microcirculatory flow and tissue perfusion. The result is improved supply of
oxygen to ischemic muscles of the limbs. In several double-blind studies,
pentoxifylline increased walking distance of patients with
intermittent claudication in comparison to placebo or
vasodilators. Like other methylxanthines,
pentoxifylline is well absorbed in the gastrointestinal tract, almost completely metabolized in the body and excreted in the urine. The most significant difference in its pharmacokinetics is that, unlike other methylxanthines, it is bound to the erythrocytic membrane where it is initially metabolized. Although
pentoxifylline has been shown to be effective in the treatment of
intermittent claudication, additional research is needed to determine its use as adjunctive
therapy in patients with concurrent coronary or
cerebrovascular disease.