From the FDA Drug Label
Metabolism and Excretion:The half-life of amoxicillin is 61. 3 minutes.
The half-life of amoxicillin is 61.3 minutes 1.
From the Research
The half-life of amoxicillin is approximately 1.27 hours in adults with normal renal function, as reported in the most recent and highest quality study 2. This means that after this time period, half of the drug has been eliminated from the body. The relatively short half-life explains why amoxicillin is typically prescribed to be taken multiple times per day (usually every 8 hours for standard formulations) to maintain therapeutic blood levels. In patients with impaired kidney function, the half-life can be significantly prolonged since amoxicillin is primarily excreted through the kidneys. For this reason, dosage adjustments are often necessary in patients with renal impairment. Some key points to consider about amoxicillin pharmacokinetics include:
- Rapid absorption in the gastrointestinal tract
- Efficient elimination through glomerular filtration and tubular secretion in the kidneys
- Significant prolongation of half-life in patients with impaired kidney function, as demonstrated in studies such as 3 and 4
- Importance of dosage adjustments in patients with renal impairment to ensure effective treatment and minimize potential side effects Despite this short half-life, amoxicillin remains an effective antibiotic because its bactericidal action continues even after the drug concentration falls below measurable serum levels, as supported by studies such as 5 and 6.