Prasugrel
Effient · Efient
Thienopyridine P2Y12 receptor inhibitor (irreversible)
Prodrug → active metabolite irreversibly blocks P2Y12. More potent + more consistent than clopidogrel (not CYP2C19-limited), but more bleeding.
Indications
- •ACS managed with PCI
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Loading | 60 mg PO | — |
| Maintenance | 10 mg PO daily (5 mg if <60 kg or ≥75 y) | — |
Pharmacokinetics
Onset ~30 min. Irreversible — effect lasts ~7–10 days.
Side effects
- !Bleeding (higher than clopidogrel)
- !Contraindicated with prior stroke/TIA
Contraindications
- ×Prior stroke or TIA (net harm — TRITON-TIMI 38)
- ×Active bleeding
- ×Age ≥75 / <60 kg (caution)
Clinical pearls
- ★ASRA neuraxial: hold 7–10 days before neuraxial procedure.
- ★Contraindicated in prior stroke/TIA — the key exam distinction from clopidogrel/ticagrelor.
Other drugs in Antiplatelets
- Aspirin
Irreversibly acetylates COX-1 → blocks thromboxane A2 for the platelet's lifespan (~7–10 days). Antiplatelet effect at low dose; analgesic/anti-inflammatory at high dose.
- Clopidogrel
Prodrug → active metabolite (CYP2C19) irreversibly blocks the platelet P2Y12 ADP receptor for the platelet lifespan.
- Ticagrelor
Directly and REVERSIBLY inhibits P2Y12 (not a prodrug, not thienopyridine). Faster onset/offset than clopidogrel.
- Ticlopidine
Irreversibly blocks P2Y12. Largely replaced by clopidogrel due to hematologic toxicity.
- Abciximab
Fab fragment that irreversibly blocks the platelet GP IIb/IIIa receptor → prevents fibrinogen cross-linking (final common pathway of aggregation).
- Eptifibatide
Reversibly blocks GP IIb/IIIa (final common pathway of platelet aggregation). Short-acting.
- Dipyridamole
Inhibits platelet PDE (↑ cAMP) and adenosine reuptake (↑ adenosine → vasodilation). Weak antiplatelet; also a coronary vasodilator used in stress testing.
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
- •ASRA regional anesthesia in the anticoagulated patient guidelines, 2018
