61 - Psychotropics with a risk of weight gain afte

Psychotropics with a risk of weight gain after bariatric surgery

854 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 10 General recommendations Box 10.5 outlines the general recommendations for prescribing in bariatric surgery, while Box 10.6 summarises the strategies used in patients who show signs of reduced bioavailability. Psychotropics with a risk of weight gain after bariatric surgery Around 70% of patients regain a significant amount of weight (more than 10% of lowest postoperative weight) within 5 years of bariatric surgery.52 There has been conflicting information on how psychotropics affect weight loss outcomes after surgery. One study reported no significant differences in total weight loss 1 year post-­surgery between those on psychotropics and those not.2 Another reported that treatment with antidepressants, particularly SNRIs and TCAs, was associated with reduced weight loss after gastric bypass surgery53 and another found that those on obesogenic medications lost statistically significantly less excess weight than controls.54 Medicines with a high risk of weight gain should be avoided where possible. Binge eating disorder, problematic alcohol use and depressive symptoms are associated with postoperative weight gain.52 Box 10.6  General management strategies for patients demonstrating signs of reduced bioavailability ■ ■Consider non-­oral routes of administration where available (e.g. depots for patients stable on antipsychotics) ■ ■Dividing doses may improve malabsorption related to a reduced stomach capacity after surgery ■ ■Switching modified/prolonged/delayed-­release to immediate-­release formulations ■ ■Switching solid tablets to liquid or orodispersible preparations to bypass disintegration phase ■ ■Switching large tablets to smaller ones ■ ■In cases where doses have been increased to account for reduced bioavailability, monitor for emergent adverse effects as bioavailability may normalise over time Box 10.5  General recommendations for prescribing in bariatric surgery7,14 Before surgery ■ ■Do not routinely increase doses; clinically relevant malabsorption cannot be reliably predicted ■ ■Assess mental state before surgery using validated scales and consider measuring baseline drug plasma levels ■ ■Switch modified-­release/ enteric-­coated preparations to immediate-­release tablets or to liquid preparations After surgery (0–­6 weeks) ■ ■Assess mental state using validated scales ■ ■Closely monitor for signs of adverse effects and drug malabsorption (symptom re-­emergence, discontinuation symptoms) ■ ■Regularly monitor drug plasma levels if clinically indicated ■ ■If malabsorption suspected consider the recommended strategies ■ ■If medication toxicity suspected withhold and reassess dose After surgery (>6 weeks after) ■ ■Continue regular monitoring for the first year postoperatively using validated scales, although frequency can be reduced if stable ■ ■Monitor for an increase in adverse effects, especially if doses were increased in the acute postoperative period ■ ■Consider returning to pre-­surgical treatment regimen after 1 year (depending on clinical history)