From the Guidelines
The half-life of Fentanyl is approximately 2.4 hours in children aged 5 months to 4.5 years, and up to 21 hours in children aged 0.5-14 years with long-term infusions. When considering the half-life of fentanyl, it's essential to take into account the age of the patient and the duration of infusion, as these factors can significantly impact the drug's elimination half-life 1. The provided evidence suggests that the half-life of fentanyl can range from 1-15 hours in pediatric patients, highlighting the importance of careful dosing and monitoring to avoid potential adverse effects 1. Some key points to consider when administering fentanyl include:
- The elimination half-life of fentanyl can be affected by individual factors such as liver function and age
- Patients with hepatic impairment may experience prolonged effects due to decreased metabolism
- Elderly patients typically have reduced clearance rates, which can impact the half-life of fentanyl
- The half-life of fentanyl can vary depending on the duration of infusion, with longer infusions resulting in a longer half-life 1. It's crucial for healthcare providers to be aware of these factors to ensure safe and effective use of fentanyl in clinical practice.
From the FDA Drug Label
The mean half-life is approximately 17 hours After system removal, serum fentanyl concentrations decline gradually, falling about 50% in approximately 17 (range 13 to 22) hours. The apparent half-life is approximately 7 (range 3 to 12) hours
The half-life of Fentanyl is approximately 17 hours when administered transdermally, but it can be as short as 7 hours when administered via IV infusion 2 2.
From the Research
Half-Life of Fentanyl
- The half-life of fentanyl is reported to be approximately 13 to 25 hours for transdermal fentanyl 3.
- However, the terminal half-life of fentanyl can range from about 1.5 to 6 hours (15 hours in geriatric patients) after single or infrequent doses 4.
- The apparent elimination half-life of fentanyl after removal of a transdermal patch is around 16 hours, due to continued absorption from the skin 5.
- The time to reach maximum fentanyl plasma concentrations can vary depending on the formulation, with oral transmucosal and intranasal routes providing faster delivery than transdermal patches 6.
Factors Affecting Half-Life
- The half-life of fentanyl can be influenced by factors such as the formulation, dose, and individual patient characteristics 3, 4.
- The pharmacokinetics of fentanyl can also be affected by its high lipophilicity and first-pass metabolism via cytochrome P450 3A 6.
- Interindividual variability in serum concentrations and clearance rates can also impact the half-life of fentanyl 3.