Tirofiban Dosing for a 90 kg Male Patient
For a 90 kg male patient, the tirofiban bolus dose should be administered as 45 mL over 3 minutes, followed by a maintenance infusion of 27 mL/hour for up to 18 hours. 1, 2
Calculation Method
Bolus Dose Calculation
- Recommended bolus dose: 25 μg/kg IV over 3 minutes 1, 2
- For a 90 kg patient: 25 μg/kg × 90 kg = 2,250 μg (2.25 mg)
- Tirofiban concentration in standard premixed bag: 50 μg/mL 2
- Bolus volume: 2,250 μg ÷ 50 μg/mL = 45 mL
Maintenance Infusion Calculation
- Recommended infusion rate: 0.15 μg/kg/min 1, 2
- For a 90 kg patient: 0.15 μg/kg/min × 90 kg = 13.5 μg/min
- Hourly rate: 13.5 μg/min × 60 min = 810 μg/hour
- Infusion volume per hour: 810 μg/hour ÷ 50 μg/mL = 16.2 mL/hour
Adjusted for Normal Renal Function
- For patients with normal renal function (CrCl > 60 mL/min): 0.15 μg/kg/min 2
- For a 90 kg patient with normal renal function: 13.5 μg/min
- Hourly infusion volume: 16.2 mL/hour
Important Clinical Considerations
Renal Function Adjustment
- If the patient has renal impairment (CrCl ≤ 60 mL/min), reduce the maintenance infusion by 50% to 0.075 μg/kg/min 3, 2
- For severe renal impairment (CrCl < 30 mL/min), the maintenance infusion should be reduced to 0.075 μg/kg/min or even 0.1 μg/kg/min based on pharmacokinetic modeling 3, 4
Administration Guidelines
- Administer the bolus dose via an IV pump within 5 minutes 2
- Immediately follow with the maintenance infusion for up to 18 hours 1
- Use the premixed 250 mL bag (50 μg/mL concentration) 2
Monitoring Requirements
- Monitor for bleeding complications, which are the most common adverse events 2
- Check platelet counts approximately 6 hours after starting treatment and daily thereafter 2
- If platelet count decreases to < 90,000/mm³, discontinue tirofiban and heparin 2
Contraindications
- Do not administer if the patient has already received another glycoprotein IIb/IIIa inhibitor 3
- Contraindicated in patients with severe hypersensitivity to tirofiban, history of thrombocytopenia following prior exposure to tirofiban, or active internal bleeding 2
Comparison with Other GP IIb/IIIa Inhibitors
Tirofiban has a shorter half-life (approximately 2 hours) compared to abciximab, allowing for faster reversal of action if needed 5. This may be advantageous in patients at higher risk of bleeding complications.
The high-dose bolus regimen (25 μg/kg) followed by 0.15 μg/kg/min infusion has been shown to provide consistent and rapid inhibition of platelet aggregation during the first hour after initiation of therapy 4, 6.