Pharmacokinetics of Ssri After Roux-En-Y-Gastric-Bypass—Review of The Literature and Case Study

Abstract

The prevalence of obesity is growing; WHO reports that in 2014 13% of adults aged 18 years and over were obese. A growing number of patients are treated with surgery, laparoscopic Roux-en-Y Gastric Bypass (RYGB) being considered the gold standard. Because of changes in intestinal anatomy, changes in pharmacokinetics are to expect. The point prevalence of depression in Sweden is 5.2%; 20-50% of patients undergoing bariatric surgery in the US have a medical history of mood disorder. However, documentation for changes in pharmacokinetics of antidepressive agents of type selective serotonin reuptake inhibitors (SSRI) is sparse. Literature was reviewed using PubMed with search terms as follows: Biliopancreatic Diversion with Duodenal Switch, BPD/DS, gastric band, gastric sleeve, gastric bypass, roux-en-Y, bariatric surgery, SSRI, psychopharmacology, selective serotonin reuptake inhibitor[s] and the names of the individual agents. From the reference lists additional references were identified. Only English-language articles were included. Three patients, treated with sertraline, were included; serum concentrations were taken eight weeks before, three month after and twelve month after surgery. 5 ml blood samples were taken 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12 and 24 hours after last intake of sertraline and analysed with LCMS/MS. Five studies with 30 patients could be identified; 22 of them after RYGB. Methods, sampling, measurements and agents varied between studies making it difficult to draw conclusions from the material. One study with case-crossover-design shows, that concentrations of sertraline, venlafaxine and citalopram decline after surgery and rise to or over concentrations before surgery. Data from serum concentrations will be delivered. More research with comparable methods and studies clarifying the clinical consequences of the pharmacokinetic changes are needed to clarify amount and relevance of changes in pharmacokinetics of SSRI after bariatric surgery.