Changes in the drugs pharmacokinetics in obese patients

Since the 1980s, the global prevalence of obesity has reached an epidemic level. In 2015, more than 100 million children and more than 600 million adults worldwide were obese. Obesity affects various physiological processes such as permeability of the intestinal wall, gastric emptying, cardiac output, liver and kidney function, which, in turn, can cause changes in the drugs pharmacokinetics. For example, obese patients have higher gastric emptying and permeability of the intestinal wall in order to provide excess adipose tissue with nutrients and oxygen. Also, obesity is associated with increased volume of circulating blood, capillary blood flow and cardiac output, which can contribute to an increase in the liver blood flow and metabolism of drugs with high hepatic extraction. The physiological features of obese patients and the associated changes in the pharmacokinetics and pharmacodynamics of drugs requires a personalisation of pharmacotherapy and dosage regimen in obese children and adults. However, summaries of product characteristics usually do not contain specific recommendations for drug dosing in patients with different body weights. This article describes potential changes in the pharmacokinetics and pharmacodynamics of drugs that must be taken into account when prescribing pharmacotherapy to obese patients.

Key words

Drugs, safety, adverse drug reactions, obesity, pharmacokinetics