Pharmacokinetics in the elderly. Studies on ciprofloxacin

Area of Science:

• Pharmacokinetics
• Geriatric Pharmacology
• Drug Metabolism

Background:

• Most drug pharmacokinetic studies use young volunteers, despite age-related physiological changes.
• Age-related alterations in the gastrointestinal tract might suggest decreased drug absorption in the elderly.
• However, empirical data on drug absorption in older adults is often contrary to these assumptions.

Purpose of the Study:

• To investigate the pharmacokinetic differences of ciprofloxacin in elderly versus young volunteers.
• To identify age-related factors influencing ciprofloxacin absorption, distribution, and elimination.
• To provide evidence-based recommendations for ciprofloxacin dosing in the geriatric population.

Main Methods:

• Comparative pharmacokinetic studies of oral ciprofloxacin in elderly and young volunteers.
• Analysis of key pharmacokinetic parameters: area under the concentration-time curve (AUC), maximal serum concentration (Cmax), volume of distribution (Vd), and total clearance.
• Assessment of renal clearance and glomerular filtration rate in relation to age.

Main Results:

• Ciprofloxacin absorption was found to be unchanged or even increased in elderly individuals compared to younger ones.
• Elderly volunteers exhibited greater AUC and Cmax, indicating enhanced absorption.
• Smaller apparent Vd and significantly reduced total body clearance (55-60% decrease) were observed in the elderly, primarily due to diminished glomerular filtration rate.

Conclusions:

• Ciprofloxacin absorption is not diminished and may be enhanced in the elderly.
• Age-related decrease in glomerular filtration rate is the primary factor affecting ciprofloxacin clearance in older adults.
• To prevent drug accumulation and potential toxicity, dosage intervals for ciprofloxacin should be extended beyond 12 hours in the elderly.