Disposition of cefoxitin in the elderly

Area of Science:

• Pharmacology
• Clinical Pharmacy
• Geriatric Medicine

Background:

• Understanding cefoxitin pharmacokinetics is crucial for optimizing patient treatment.
• Age-related physiological changes can significantly alter drug metabolism and elimination.
• Investigating cefoxitin's behavior in different age groups is essential for safe and effective use.

Purpose of the Study:

• To investigate and compare the pharmacokinetics of cefoxitin in younger and geriatric patient populations.
• To determine the influence of age on cefoxitin's distribution, elimination, and metabolic parameters.
• To assess the need for dosage adjustments in geriatric patients receiving cefoxitin.

Main Methods:

• Single intravenous (i.v.) and intramuscular (i.m.) doses of cefoxitin (15 mg/kg) were administered to two groups: younger adults (15-55 years) and geriatric patients (66-94 years).
• Pharmacokinetic parameters were analyzed using an open two-compartment model for both administration routes.
• Key parameters including distribution, elimination rate constants (alpha, beta, K12, K21, K13), clearance (Clp), and apparent volume of distribution (Vdss) were evaluated.

Main Results:

• Cefoxitin pharmacokinetics followed an open two-compartment model for both i.v. and i.m. routes.
• Intramuscular administration resulted in altered distribution compared to i.v., with decreased beta (elimination rate constant) and increased Vp (central volume).
• Geriatric patients exhibited decreased pharmacokinetic parameters (alpha, beta, K12, K21, K13, Clp) and increased Vdss compared to younger individuals, with a linear correlation between beta and age.

Conclusions:

• Significant pharmacokinetic modifications of cefoxitin occur in geriatric patients compared to younger adults.
• Despite observed age-related pharmacokinetic changes, cefoxitin possesses a wide safety margin.
• Current cefoxitin dosage regimens are considered appropriate for geriatric patients without modification.