Impact of Bariatric Surgery in the Short and Long Term: A Need for Time-Dependent Dosing of Drugs

Abstract

Sparse information is available on pharmacokinetic changes of drugs over time after bariatric surgery. By reviewing the literature on the short- and long-term pharmacokinetic changes of drugs, several patterns were identified for 39 drugs. No relevant pharmacokinetic changes were identified for roughly a third of the drugs. Of the remaining drugs, levels were variable and partly unpredictable shortly after the surgery. In the long term, most of the drug levels remain altered, but in some cases they returned to preoperative values. Based on the changes and the efficacy-safety balance of each drug, clinicians may need to perform additional clinical monitoring for specific drugs, including measuring drug levels. This review provides suggestions for clinicians and pharmacists for specific time-dependent drug dosing advice.

Keywords: Bariatric surgery; Pharmacokinetics; Roux-en-Y gastric bypass; Sleeve gastrectomy.

Fig. 1

Flowchart of included articles. * For drugs whose pharmacokinetics are usually not measured, the used dosages and/or laboratory values were used (i.e., vitamin K antagonists and thyroid hormones). BPD = biliopancreatic diversion

Fig. 2

Numbers of studied drugs of which the pharmacokinetics were assessed at multiple time points up to 1 year after bariatric surgery (A) and from 1 to 5 years after surgery (B). The Y-axis depicts the number of studied drugs. The size of the dots indicates the total number of patients that were studied