Overmedication of the low-weight elderly.

Area of Science:

• Geriatric Pharmacology
• Clinical Pharmacy
• Drug Dosing

Background:

• Accurate drug dosing is critical for patient safety, particularly in elderly populations.
• Age-related physiological changes can affect drug metabolism and excretion.
• Body weight is a key factor in determining appropriate medication dosages.

Purpose of the Study:

• To investigate the relationship between patient age, body weight, and prescribed drug doses.
• To identify risks of overmedication in elderly and low-weight patient groups.
• To evaluate dosing practices for cimetidine hydrochloride, flurazepam hydrochloride, and digoxin.

Main Methods:

• Analysis of prescription data from a national pharmacy service for 1797 patients.
• Examination of drug doses (milligrams per kilogram) in relation to patient weight and age.
• Statistical correlation analysis between weight and dose for three tracer drugs.

Main Results:

• A significant negative correlation was observed between body weight and drug dose (mg/kg) for all three drugs (-0.34 to -0.40).
• Patients weighing ≤50 kg received 31-46% higher doses than the mean and 70-88% higher than patients >90 kg.
• No dose reduction trend was observed for older patients, despite declining body weight.

Conclusions:

• Low body weight is a significant risk factor for medication overdosage in the elderly.
• Physicians need to consider low body weight as a critical factor for dose adjustment in elderly patients.
• Current prescribing practices may lead to increased drug toxicity risk in low-weight elderly individuals.