Nursing Challenges in the Administration of Oral Antidepressant Medications in Gastric Bypass Patients

Decreased Escitalopram Concentrations Post-Roux-en-Y Gastric Bypass Surgery

BACKGROUND

There is a high coincidence between obesity and psychiatric disorders including depression. Depressive disorders are commonly treated with antidepressants, including the selective serotonin reuptake inhibitor Lexapro (escitalopram). Although candidates for elective Roux-en-Y gastric bypass (RYGB) surgery may be treated with escitalopram, drug dosing strategies are typically not adjusted postoperatively. Therefore, studies are needed to better characterize escitalopram drug concentrations in a postsurgical setting.

METHODS

Turbulent flow-liquid chromatographic-tandem mass spectrometric methods were used to quantify escitalopram concentrations in serum in study participants approved for RYGB. Blood was collected from study subjects 2 weeks before surgery, and 2 and 6 weeks postoperatively, to assess the impact of RYGB on systemic drug concentrations.

RESULTS

Twelve samples from 4 study participants were collected and analyzed for serum escitalopram concentrations. Two weeks post-RYGB, although there were minimal changes in each participant's body mass index (<5%), drug concentrations were 33% (4%-71%) decreased as compared with presurgical serum concentrations. There were further decreases in drug concentrations 6 weeks postsurgery. All clinical laboratory values were within normal reference intervals.

CONCLUSIONS

RYGB significantly alters the gastrointestinal tract and impacts escitalopram drug concentrations, even shortly after surgery.

[Bariatric surgery, stomas and other digestive tract reductions: Insufficient data and recommendations to adapt medicines regimens in therapeutic practice]

Surgery modifying digestive tract may alter drugs pharmacokinetics. To maintain concentrations of active substance in their therapeutic ranges, a dosage adjustment or change of drug may be necessary. This is particularly important when no pharmacological or pharmacodynamic parameter reflecting the medication effectiveness is easily measurable. Our objective was to gather the information and documentary tools that can guide prescription in these patients with rearranged digestive tract. We searched information on the documentary portals of French agencies, on gray literature, on MEDLINE and in the summaries product characteristics. No information was found on the website of French agencies, sparse data were identified in gray literature. Some document are discordant, most are imprecise. One hundred and ten studies or case reports referenced on MEDLINE describe 79 medications pharmacokinetics after gastrointestinal surgery. Four are not available in France. Six literature reviews were found. Four summaries of product characteristics provided information related to drug absorption. No documentary tool adapted to clinical routine exists. This unsatisfactory situation is a barrier to optimal patients care. Information is available. It is however necessary to gather under an ergonomic shape adapted to clinical routine, bringing the surgery type, pharmacokinetic changes induced and what to do about the dose adjustment.