Pentoxifylline (oxpentifylline). A review of its therapeutic efficacy in the management of peripheral vascular and cerebrovascular disorders.

Pentoxifylline (oxpentifylline) has been used widely in the treatment of intermittent claudication, a prevalent condition in the elderly population. The exact mechanism(s) of action of the drug are unclear, but may be related to identified effects on white blood cell function and haemorrheological parameters. Clinical trials which conform best with European and North American guidelines have shown that 6 months' oral therapy with pentoxifylline 1200 mg/day significantly improves walking distances in patients with intermittent claudication. Patients most likely to benefit from treatment are those with an ankle/arm blood pressure ratio < or = 0.8 and a history of disease > 1 year. However, it remains unclear whether pentoxifylline or any other conservative treatment approach (including physical training) offers long term benefit, as studies comparing the development of intermittent claudication after several years of treatment with the natural course of the disease are still lacking. In patients with more severe vascular disease, intravenous administration of pentoxifylline (1200 mg/day for 21 days) decreased rest pain in patients with critical limb ischaemia. Oral administration (1200 g/day for up to 6 months) increased the healing of venous ulcers of the leg when used as an adjunct to standard compression bandaging. However, further studies are required to confirm these initial findings. The efficacy of pentoxifylline in the treatment of cerebrovascular disease has been evaluated in controlled clinical trials. Most notably, long term therapy (1200 mg/day) may slow the progression of dementia in patients who meet the clinical diagnostic criteria for 'multi-infarct' dementia and who also have clinical and neuroradiological evidence of cerebrovascular disease. The drug is effective in decreasing the risk of transient ischaemic attacks, but there are insufficient data to determine its value in the prevention and treatment of stroke. Pentoxifylline is well tolerated, with gastrointestinal effects reported in fewer than 3% of treated patients. However, the incidence of adverse events may be higher in elderly patients and/or those receiving concomitant medications. In summary, pentoxifylline is the most established agent when drug therapy is deemed appropriate in patients with intermittent claudication. Moreover, a promising new development for the drug is in the management of cerebrovascular dementia, an area where few therapeutic options are currently available.