Past Papers · SAQ
Heparin vs Enoxaparin
2008A Q02
Exam questionOutline the differences between heparin and enoxaparin with respect to:
a. Phamacokinetics
b. Monitoring of effect
c. Adverse effects
d. Reversal of effect
CICMWrecks answer
Master answer
Heparin
- Binds to, and stabilizes anti-thrombin 3-thrombin complex
- → Potentiates the degradation of thrombin (does not occur with LMW heparins)
- Also aids antithrombin 3 degradation of factors IX and X (major function of LMW heparins)
| HEPARIN | ENOXAPARIN | ||
|---|---|---|---|
| PK | A | Subcut or IV administration | Subcut administration |
| ~90% bioavailability SC due to tissue binding | >95% bioavailability SC – NOT bound in tissues | ||
| D | 5% protein bound | 5% protein bound | |
| Vd – 0.3l/kg | Vd – 0.3l/kg | ||
| M | Heparinases | Minimal metabolism | |
| E | Renal elimination of inactive metabolites | Renal elimination of unchanged drug Dosage adjustment required in renal failure | |
| T1/2b ~2 hours | T1/2b 4~6 hours | ||
| Monitoring | APTT, activated clotting time | Anti-Xa assay (expensive, time-consuming) | |
| Adverse Effects | Bleeding | Bleeding | |
| Heparin induced thrombocytopoenia | Less likely to develop HITS | ||
| Osteoporosis | Less likely to develop Osteoporosis | ||
| Reversal | Reversal with protamine sulfate | Partial (40%) reversal with protamine sulfate | |
Sakurai 2016
Past papers
Exam appearances
| Exam | Exact exam wording | Candidate success |
|---|---|---|
| 2008A Q02 | Outline the differences between heparin and enoxaparin with respect to: a. Phamacokinetics b. Monitoring of effect c. Adverse effects d. Reversal of effect | 33% |