Drug metabolism and pharmacokinetics in malnutrition

Abstract

Malnutrition is one of the major public-health problems of the Third World and several million people are underfed and suffer from deficiencies of essential nutrients. Drugs, though not an answer to the problem of malnutrition, do play an essential role in various health projects. However, nutrient-drug interactions, particularly in humans, have attracted very little attention. Only recently have data accumulated to indicate that under-nutrition and malnutrition have great potential for altering drug metabolism and disposition, which may have direct clinical relevance. The pathophysiological changes encountered in both macro- and micro-nutrient deficiencies are such that they can interfere with pharmacokinetic and pharmacodynamic processes in the body which may result in altered drug response. Studies in laboratory animals and in malnourished human subjects indicate that dietary factors and nutritional status considerably influence absorption, plasma protein binding, distribution, biotransformation and excretion of drugs. Therapeutic response and toxicity are therefore likely to be altered. Data obtained show that the doses and dosage regime in the under-nourished or malnourished depend on three factors, namely environment, patient and the drug concerned. A wide variety of environmental factors, operating at different levels, and their interaction with the complex problem of malnutrition, of varying types and severity, need to be considered and evaluated properly in the under-nourished population.