According to a retrospective cross-sectional study published in “Medicine in Drug Discovery”, severely obese patients (body mass index of more than 40 kg/m2) who underwent bariatric surgery experienced significant reduction in serum alpha-1-acid glycoprotein (AAG) causing lesser drug-drug interactions.

Obesity has negative consequences on pharmacokinetic and pharmacodynamic parameters, which affects drug efficacy and toxicity. AAG and albumin are the two crucial proteins responsible for drug binding in human beings. In the pre-operative period and after 12 months, this study examined the pharmacotherapeutic profile and interfering factors in people undergoing bariatric surgery.

Determination of serum AAG and possible drug-drug interactions was done in severe obesity patients who underwent bariatric surgery. The most extensively used drug classes were cardiovascular, antidepressants (selective serotonin reuptake inhibitors), and lipid-modifying drugs, which decreased after a year.

More than half of the patients had a minimum of one drug interaction (mostly moderate) in their treatment plan prior to the surgery. Drug interactions lowered after the surgery. A significant decrease in serum AAG after 12 months was witnessed, which could affect the free fraction of drugs with higher affinity and its effect on efficiency. Hence, protein binding is modified following bariatric surgery and influences the pharmacodynamics of a few drugs.