Dosing and uses of Retavase (reteplase)
Adult dosage forms and strengths
powder for injection
- 10.4 units (18.1mg)
Acute Myocardial Infarction
10 units IV bolus (over 2 minutes), THEn
Second dose given 30 minutes after first (for total cumulative dose of 20 units)
Treatment should be initiated ASAP after onset of AMI
Give each bolus injection via an IV line in which no other medication is being simultaneously injected or infused
Pediatric dosage forms and strengths
Safety & efficacy not established
Retavase (reteplase) adverse (side) effects
Frequency not defined
Reperfusion arrhythmias, hypotension
Dizziness, fever, severe headache
Anemia, cholesterol embolization, GI/GU bleeding, intracranial hemorrhage
Nausea, vomiting
Cardiac reinfarction
Cardiogenic shock
Muscle pain
Allergic reaction, injection site reaction
Warnings
Contraindications
Hypersensitivity
Active bleeding, recent CVA, recent intracranial or intraspinal surgery or trauma, intracranial neoplasm, AVM, aneurysm, bleeding diathesis, severe uncontrolled HTn
See thrombolytic indications/contraindications
Cautions
Recent major surgery, cerebrovascular disease, recent GI or GU bleeding, HTN, acute pericarditis, hemostatic defects, severe thrombophlebitis, severe hepatic/renal dysfunction, currently receiving oral anticoagulants, diabetic hemorrhagic retinopathy, elderly
Monitor potential bleeding sites
Cholesterol embolism reported
Ischemic Stroke: may have no benefit if used after 3 hr of onset
Current use of warfarin and INR in high range may increase bleeding risk
Pregnancy and lactation
Pregnancy category: C
Lactation: Not known whether drug crosses into breast milk, unlikely patients will be concerned about nursing in indicated circumstances
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Retavase (reteplase)
Mechanism of action
Reteplase is the r-PA (recombinant plasminogen activator) with nonglycosylated deletion mutant of wild-type tissue plasminogen activator (tPA); has less high-affinity fibrin binding, longer half-life, & greater thrombolytic potency than tPA
Promotes thrombolysis by converting plasminogen to plasmin which degrades fibrin & fibrinogen
Pharmacokinetics
Half-Life: 13-16 min
Onset: Coronary thrombolysis occurs in 30 min, reaches peak response at 30-90 min
Metabolism: Inactivated by blood components C1 inactivator, alfa-1-antitrypsin, alfa-2-antiplasmin
Excretion: Urine and feces
Plasma clearance: 250-450 mL/min
Administration
IV Incompatibilities
Y-site: bivalirudin
Additive, Syringe, Y-site: heparin
IV Preparation
Reconstitute using diluent, needle, syringe & dispensing pin provided to obtain 1 U/mL soln
IV Administration
Bolus over 2 min
Do not admin solutions that are discolored or contain precipitate
Slight foaming may occur
- May need to stand undisturbed for several minutes to dissipate bubbles
Flush before & after each bolus
Line to contain D5W
Stability
Stable for 4 hr at room temp
