Tenecteplase: new preparation. Another thrombolytic agent for myocardial infarction: a slightly simpler treatment.

(1) Alteplase is the standard thrombolytic agent for treating patients under 75 years with myocardial infarction if they are seen within 6 hours. It is given as an intravenous infusion over 90 minutes in combination with aspirin and unfractionated or low-molecular-weight heparin. (2) Tenecteplase has been authorized for use in myocardial infarction as an intravenous bolus over 5 to 10 seconds. (3) The evaluation file on tenecteplase contains data from three dose-finding studies and one double-blind trial against alteplase in nearly 17 000 patients. The trial found no difference in mortality between the two treatments (6% at 30 days). Nor was there any substantial difference in serious adverse events (stroke, intracranial haemorrhage or heart failure). (4) Major haemorrhage was slightly less frequent in patients given tenecteplase, but there was no difference between groups in the incidence of intracranial haemorrhage or stroke. (5) A comparative trial suffering from a number of biases suggests that combined treatment with tenecteplase + enoxaparin has a similar risk-benefit ratio to combined treatment with tenecteplase + unfractionated heparin. The combination of tenecteplase and enoxaparin makes treatment simpler, which could be particularly useful prior to hospital admission. A smaller trial of alteplase + enoxaparin against alteplase + unfractionated heparin gave similar findings. (6) In practice, tenecteplase has the advantage of a more convenient administration; a very large trial strongly suggests that its effects are almost identical to those of alteplase.