From the Guidelines
The half-life of fentanyl in pediatric patients is approximately 2.4 hours, with a range of 1-15 hours, as indicated in the study published in Pediatrics 1. When considering the half-life of fentanyl, it's essential to note that this value can vary depending on several factors, including the patient's age, liver function, and the presence of any organ dysfunction.
- The study provides a range of half-lives for fentanyl in pediatric patients, from 1-15 hours, highlighting the importance of individualized dosing and monitoring.
- Fentanyl is a potent opioid analgesic that is commonly used in critically ill patients, and its half-life can impact the timing of neurological examinations and the determination of brain death.
- As noted in the study, the elimination half-life of a medication does not guarantee therapeutic drug levels, especially for longer-acting medications or those with active metabolites 1.
- Therefore, it is crucial to consider the pharmacokinetics and pharmacodynamics of fentanyl when using it in clinical practice, particularly in pediatric patients, to ensure safe and effective pain management.
From the FDA Drug Label
After system removal, serum fentanyl concentrations decline gradually, falling about 50% in approximately 17 (range 13 to 22) hours. Continued absorption of fentanyl from the skin accounts for a slower disappearance of the drug from the serum than is seen after an IV infusion, where the apparent half-life is approximately 7 (range 3 to 12) hours
- The half-life of fentanyl is approximately 7 hours (range 3 to 12 hours) after an IV infusion.
- After transdermal system removal, the half-life is approximately 17 hours (range 13 to 22 hours) due to continued absorption from the skin 2
From the Research
Fentanyl Half-Life
- The half-life of fentanyl is not explicitly stated in the provided studies 3, 4, 5, 6, 7.
- However, the study by 3 discusses the pharmacokinetics of fentanyl, including its distribution and elimination half-lives, but does not provide a specific value for the half-life.
- The other studies 4, 5, 6, 7 do not mention the half-life of fentanyl.
- It appears that the provided studies do not offer a clear answer to the question of fentanyl's half-life.
Related Pharmacokinetic Properties
- The study by 3 mentions that alfentanil has the shortest distribution and elimination half-lives compared to fentanyl and sufentanil.
- The same study notes that the pharmacokinetics of opioid analgesics, including fentanyl, can be affected by factors such as patient age, plasma protein content, and acid-base status.
- However, without explicit information on fentanyl's half-life, it is difficult to draw conclusions about its pharmacokinetic properties in relation to its half-life.