Stroke patients treated rapidly with the thrombolytic drug t-PA have a greater chance to recover, a study in The Lancet reports.

Six clinical trials involving more than 2,700 acute ischemic stroke patients in 18 countries found that those treated with thrombolytic t-PA within 90 minutes of having a stroke had the best outcomes. The key is timing: the study suggests that t-PA may be of some benefit to patients treated up to four hours after symptoms initially occur, but those treated in a five- to six-hour window did not reap the benefits.

Currently, only 2% to 5% of all eligible stroke patients receive t-PA. The drug was approved by the Food and Drug Administration in 1996 to treat ischemic stroke within three hours of symptom onset.

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