Conclusions
Bariatric surgery is increasingly employed for (morbid) obesity because it improves long-term morbidity and mortality. As a result of changes in the gastrointestinal tract that subsequently result in major weight loss, the pharmacokinetics of drugs in patients after bariatric surgery may be subject to alterations in the absorption, distribution, metabolism, and/or elimination. Due to an increased absorption rate after bariatric surgery, the time at maximum concentration is often earlier and the maximum concentration may be higher with less consistent effects on trough concentrations and exposure or area under the curve upon oral drug administration. We conclude that based on current literature an advice can be proposed in many cases but also that there is insufficient evidence for general dosing recommendations for oral drug therapy after bariatric surgery implying a risk assessment on a case by case basis.