From the Guidelines
The half-life of Propranolol is approximately 3-6 hours for oral administration, with an intravenous half-life of 2.4 hours and an extended-release half-life of 8-20 hours. This information is based on the most recent and highest quality study available, as reported in the 2024 guideline for the diagnosis and management of atrial fibrillation 1. The half-life of propranolol can vary depending on several factors, including:
- Dosage form: Immediate-release propranolol has a shorter half-life compared to extended-release formulations
- Individual metabolism: Factors such as liver function, age, and genetics can affect how quickly the body processes propranolol
- Frequency of use: With regular dosing, propranolol can accumulate in the body, potentially extending its effects For most clinical applications, propranolol is dosed 2-4 times daily due to its relatively short half-life, as indicated in the guideline 1. This frequent dosing helps maintain steady blood levels of the medication for optimal therapeutic effect. However, extended-release formulations allow for once-daily dosing in some cases. Understanding the half-life is crucial for proper dosing and anticipating how long the drug's effects will last, as noted in the context of atrial fibrillation management 1.
From the FDA Drug Label
In a study of 12 elderly (62 to 79 years old) and 12 young (25 to 33 years old) healthy subjects, the clearance of S-enantiomer of propranolol was decreased in the elderly. Additionally, the half-life of both the R- and S-propranolol were prolonged in the elderly compared with the young (11 hours vs. 5 hours) In the patients with cirrhosis, the half-life obtained after a single intravenous dose of 10 mg propranolol increased to 7. 2 hours compared to 2. 9 hours in control Studies have reported a delayed absorption rate and a reduced half-life of propranolol in patients with renal failure of varying severity
The half-life of Propranolol is:
- 5 hours in young healthy subjects
- 11 hours in elderly healthy subjects
- 2.9 hours in healthy subjects with normal liver function
- 7.2 hours in patients with cirrhosis Note that the half-life may be affected by factors such as age, renal function, and liver function. 2
From the Research
Half-Life of Propranolol
The half-life of propranolol varies depending on several factors, including the route and duration of administration, as well as individual differences in plasma binding and liver function.
- After intravenous administration, the half-life of propranolol is approximately 2-3 hours among individuals 3.
- With continued administration, the half-life is prolonged to 3-6 hours 3.
- For long-acting propranolol, the terminal half-life is 8-11 hours due to slower absorption from the gut 4.
- In patients with cirrhosis, the elimination half-life of propranolol tends to be prolonged, with a median of 7.15 hours compared to 2.92 hours in normal controls 5.
- Ageing also affects the pharmacokinetics of propranolol, with higher plasma concentrations and greater bioavailability observed in elderly subjects compared to young subjects 6.
Factors Affecting Half-Life
Several factors can influence the half-life of propranolol, including:
- Plasma binding: Propranolol is 90-95% bound to plasma, and individual differences in plasma binding can affect the half-life 3.
- Liver function: Hepatic removal of propranolol is avid, and liver function can impact the half-life 3.
- Route of administration: The half-life of propranolol varies depending on whether it is administered intravenously or orally 3, 4.
- Duration of administration: Continued administration of propranolol can lead to a prolonged half-life 3.