Methylxanthines can enlarge brain blood vessels but are of no apparent benefit in the early treatment of strokes caused by blood clots. Most strokes are caused by a blood clot which then reduces blood flow in the affected part of the brain. Without an adequate blood supply, the brain quickly suffers damage which is often permanent. Drugs which can improve brain blood flow might reduce damage and improve outcome after stroke. Methylxanthines can alter brain blood flow but we do not know if they improve patient recovery. We found five small trials which do not show any clear benefit. The use of methylxanthines in acute stroke cannot be recommended at present.
Baca abstrak penuh
Methylxanthine derivatives are vasodilators. They also inhibit platelet aggregation and thromboxane A2 synthesis, decrease the release of free radicals and may be neuroprotective. This review covers an area where no active research is taking place. It will be updated if relevant information becomes available, e.g. on completion of an appropriate study.
Matlamat
To assess the effect of intravenous or oral methylxanthines (pentoxifylline, propentofylline, or pentifylline) in patients with acute ischaemic stroke.
Kaedah Pencarian
We searched the Cochrane Stroke Group trials register (last searched November 2003). For the first version, we also searched EMBASE (1980 to 1999), MEDLINE (1966 to 1999), Science Citation Index (1981 to 1999) and the Ottawa Stroke Trials Registry. We also contacted the manufacturers of methylxanthines and the principal investigators of the identified trials.
Kriteria Pemilihan
Randomised trials comparing pentoxifylline, propentofylline or pentifylline with placebo or control in patients with definite or presumed acute ischaemic stroke. Trials were included if treatment was started within one week of stroke onset.
Pengumpulan Data dan Analisis
Two review authors independently applied the inclusion criteria. Trial quality was assessed.
Keputusan Utama
Five trials were included. Four trials tested pentoxifylline in 763 people, and one tested propentofylline in 30 people. No trials of pentifylline were found. The odds of early death (within four weeks) was non-significantly reduced in patients given a methylxanthine drug as compared with those given placebo (odds ratio (OR) 0.64, 95% confidence interval (CI) 0.41 to 1.02). This non-significant trend to less deaths was due mainly to one pentoxifylline trial that found a highly significant reduction in early deaths. Two trials reported early death or disability and found a non-significant reduction (OR 0.49, 95% CI 0.20 to 1.20). There was no significant difference in late death (beyond four weeks), as reported in the propentofylline trial involving 30 patients, although the confidence interval was wide (OR 0.70, 95% CI 0.13 to 3.68). Data for neurological impairment and disability were not in a form suitable for analysis. Data on quality of life, stroke recurrence, thromboembolism and bleeding were not reported.
Kesimpulan Pengarang
There is not enough evidence to assess adequately the effectiveness and safety of methylxanthines after acute ischaemic stroke.
