Onset of Action of Oral Ticagrelor (Brilinta)
Oral ticagrelor (Brilinta) has an onset of action of approximately 30 minutes, with peak effect achieved at about 2 hours after administration.
Pharmacokinetic Profile
Ticagrelor is an oral, reversibly binding P2Y12 receptor antagonist with the following key pharmacokinetic properties:
- Initial onset: Begins inhibiting platelets within 30 minutes of oral administration 1
- Peak effect: Maximum plasma concentration (Cmax) reached in 1-2 hours 2, 1
- Half-life: 6-12 hours for the parent drug, 9 hours for the active metabolite 3, 1
- Bioavailability: Approximately 36% 3
- Metabolism: Primarily via CYP3A4 and to a lesser extent CYP3A5 3
Advantages Over Other P2Y12 Inhibitors
Ticagrelor offers several pharmacodynamic advantages compared to thienopyridines like clopidogrel:
- Faster onset of action: Achieves platelet inhibition more rapidly than clopidogrel 1, 4
- More potent inhibition: Provides greater and more consistent inhibition of platelet aggregation 5
- Reversible binding: Unlike thienopyridines which bind irreversibly to P2Y12 receptors 1
- No metabolic activation required: Acts directly without needing hepatic conversion to an active form 4
Clinical Implications
The rapid onset of action has important clinical implications:
- Acute coronary syndromes: Particularly beneficial in ACS where rapid platelet inhibition is crucial 3
- Pre-procedural loading: 180 mg loading dose recommended before PCI 1
- Recovery of platelet function: Occurs more quickly (3-5 days) than with thienopyridines (5-7 days) 1
Important Considerations
- Dosing regimen: 180 mg loading dose followed by 90 mg twice daily maintenance 3, 1
- Discontinuation before surgery: Should be stopped at least 5 days before planned surgery 3, 1
- Twice-daily dosing: Compliance is critical due to the shorter half-life and twice-daily regimen 1
- Common side effects: Dyspnea (occurs in up to 15% of patients) and bradycardia 3
Special Populations
Despite the rapid onset of action in most patients, certain factors may affect ticagrelor's pharmacodynamics:
- STEMI patients: May experience delayed onset of action (4-6 hours for full effect) compared to stable CAD patients (30 minutes) 3
- Drug interactions: Concomitant use with strong CYP3A4 inhibitors or inducers may affect ticagrelor's pharmacokinetics 3
The rapid onset of action makes ticagrelor particularly valuable in acute settings where quick platelet inhibition is essential for reducing thrombotic events.