MIREL

Indications

• Acute myocardial infarction
• Pulmonary embolism
• Thrombotic stroke

Dosage

Children: Refer to the BNF for Children for specific dosing guidance.

Adults: Refer to the BNF for specific dosing guidance.

Mechanism of action

Reteplase works by binding to fibrin in a thrombus (blood clot) and converting plasminogen to plasmin, which is an active proteolytic enzyme that breaks down fibrin, thus dissolving the clot. This process restores blood flow to the affected area, which is critical in the treatment of ischemic conditions such as myocardial infarction.

Pharmacodynamics

Reteplase exhibits a rapid onset of action, with peak thrombolytic activity occurring within 30 minutes of administration. The drug has a relatively short half-life, necessitating its use in a hospital setting where monitoring can occur. Its efficacy in dissolving clots is influenced by factors such as the size and age of the clot, as well as patient-specific variables.

Pharmacokinetics

After intravenous administration, reteplase has a rapid distribution phase followed by a slower elimination phase. It is primarily cleared from the circulation through hepatic metabolism. The half-life of reteplase is approximately 13 to 16 minutes. Renal excretion plays a minor role in its elimination, thus liver function is a more critical factor in its clearance.

Contra-indications

• Active internal bleeding
• History of cerebrovascular accident within the last 6 months
• Severe uncontrolled hypertension
• Recent surgery or trauma
• Allergy to reteplase or any component of the formulation

Adverse effects

• Hemorrhage
• Nausea
• Vomiting
• Hypotension
• Arrhythmias
• Anaphylaxis
• Reperfusion injury

Interactions

• Anticoagulants may increase the risk of bleeding
• Antiplatelet agents may enhance the risk of hemorrhage
• Other thrombolytics used concurrently can increase the risk of adverse effects

Precautions

• Use with caution in patients with a history of gastrointestinal bleeding
• Monitor closely for signs of bleeding or bruising
• Assess renal and hepatic function before use
• Patients with recent surgery should be evaluated carefully

Pregnancy

Reteplase should only be used in pregnancy if clearly needed, as safety has not been established.

Breast-feeding

It is not known whether reteplase is excreted in human milk; use caution when administering to nursing mothers.

Storage

Store in a refrigerator at 2-8 degrees Celsius. Do not freeze. Protect from light.

Formulations

• Reteplase powder for solution for injection