Anistreplase: a new thrombolytic for the treatment of acute myocardial infarction.

The chemistry, pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of anistreplase in the treatment of acute myocardial infarction (AMI) are reviewed. Anistreplase is an acylated form of the streptokinase-plasminogen complex. Acylation makes the complex temporarily inactive but protects it from neutralization by plasmin inhibitors. After deacylation, which begins immediately after injection, the streptokinase-plasminogen complex promotes thrombolysis by speeding the conversion of plasminogen to plasmin. Like other thrombolytic agents, anistreplase induces a systemic fibrinogenolytic state. The plasma half-life of anistreplase, 88-112 minutes, is longer than that of the other thrombolytic drugs marketed in the United States. Anistreplase lyses coronary artery thrombi when given by the intracoronary or i.v. route. I.V. anistreplase is comparable in efficacy to i.v. streptokinase but has not been directly compared with i.v. alteplase. Anistreplase therapy in patients with AMI may help preserve left ventricular function and prolong survival. Anistreplase is comparable in safety to other thrombolytic drugs. Although bleeding has occurred in 4-47% of patients treated with anistreplase, most episodes have been clinically unimportant and have occurred at a vascular puncture site; intracranial hemorrhage has occurred in less than 1% of patients. Cardiac arrhythmia and transient hypotension are common after anistreplase administration. Anistreplase is easy to administer and may be appropriate for use in patients with suspected AMI before hospital admission. The recommended dose is 30 units i.v. given over two to five minutes. Anistreplase is similar in efficacy and safety to other thrombolytic agents in the treatment of AMI. The drug's ease of administration may be an important clinical consideration.