Prozac (Fluoxetine) Does Not Need to Be Held Before Bariatric Surgery
You should continue Prozac (fluoxetine) through the perioperative period without interruption before bariatric surgery. 1
Evidence-Based Rationale
The most recent Enhanced Recovery After Surgery (ERAS) Society guidelines for bariatric surgery explicitly address psychiatric medications and recommend continuation of all antidepressants perioperatively to avoid withdrawal syndrome. 1 This recommendation is based on the principle that the risks of abrupt discontinuation—including withdrawal symptoms, mood destabilization, and potential psychiatric decompensation—outweigh any theoretical perioperative concerns. 1
Key Clinical Considerations
Antidepressants should be continued without interruption because:
Stopping SSRIs like fluoxetine can precipitate withdrawal syndrome, which manifests as dizziness, nausea, anxiety, irritability, and flu-like symptoms that would complicate postoperative recovery. 1
Bariatric surgery patients have high rates of mood disorders (56.4% in one veteran cohort), making psychiatric stability crucial during the perioperative period. 2
The Society for Perioperative Assessment and Quality Improvement (SPAQI) consensus specifically states that antidepressants should be continued to maintain therapeutic benefit and avoid destabilization. 3
Important Monitoring Considerations
While continuing fluoxetine, be aware of serotonin syndrome risk:
Fluoxetine has serotonin reuptake inhibitory activity, which increases risk when combined with other serotonergic agents commonly used perioperatively (ondansetron, metoclopramide, fentanyl, tramadol). 3
Monitor for neuroexcitatory symptoms, autonomic dysfunction, and neuromuscular abnormalities if multiple serotonergic medications are administered concurrently. 3, 1
This does not mean holding fluoxetine—it means heightened vigilance when adding other serotonergic agents. 3
Postoperative Absorption Changes
Understand that bariatric surgery will alter fluoxetine pharmacokinetics:
Roux-en-Y gastric bypass (RYGB) is most frequently associated with altered drug exposure, affecting disintegration, dissolution, absorption, metabolism, and excretion. 4
Serum concentrations of antidepressants demonstrate considerable variability after bariatric surgery due to unique pharmacokinetic features and surgical anatomy changes. 5
For sertraline (another SSRI), dose-adjusted concentrations decreased by 51% after surgery, with the pre-surgery low-calorie diet explaining much of this reduction. 6
Lipophilic drugs like fluoxetine may have decreased serum concentrations after the pre-surgery low-calorie diet and following the procedure itself. 6
Postoperative management strategy:
Continue fluoxetine at the same dose immediately postoperatively. 1
Monitor clinical response closely over the first 3-6 months, as absorption changes may necessitate dose adjustments. 5
Consider therapeutic drug monitoring if clinical response changes or depressive symptoms re-emerge. 6
Unlike medications for diabetes or hypertension which are often reduced post-surgery, antidepressant use typically continues at similar or increased rates. 4, 2
Long-Term Psychiatric Outcomes
Be prepared for ongoing psychiatric needs:
Depression treatment may actually increase after bariatric surgery—one study showed greater persistence of depression treatment at 5 years post-surgery compared to controls (OR=1.24-1.27). 7
Incident depression treatment was 27-34% higher in surgical patients without baseline depression treatment compared to matched controls. 7
While antidepressant use for depression declined from 56.4% pre-surgery to 34.6% at 5 years in one cohort, anxiolytic use actually increased from 23.6% to 32.7%. 2
This underscores that psychiatric monitoring should continue long-term, not just perioperatively. 7
Common Pitfalls to Avoid
Do not discontinue fluoxetine based on outdated concerns:
There is no evidence that continuing SSRIs increases surgical complications, bleeding risk, or anesthetic complications in bariatric surgery. 3
The 2005 guideline mentioning fluoxetine for weight loss (3.15 kg at 12 months) is irrelevant to the perioperative management question—this was about using fluoxetine as a weight loss agent, not about holding it before surgery. 3
Do not confuse fluoxetine management with GLP-1 receptor agonists:
Unlike GLP-1 agonists which delay gastric emptying and require specific holding protocols (3 half-lives before surgery), fluoxetine has no effect on gastric emptying and does not increase aspiration risk. 3, 1
The extensive preoperative holding recommendations for GLP-1 agonists do not apply to psychiatric medications. 3