Anesthesia Care for Patients on MAO Inhibitors
Continue MAO inhibitors perioperatively rather than discontinuing them, as the psychiatric risk of stopping these medications outweighs the manageable anesthetic risks when appropriate precautions are taken. 1, 2
Key Principle: Continuation vs. Discontinuation
The traditional recommendation to discontinue MAO inhibitors 2-3 weeks before elective surgery is outdated and potentially harmful 1, 3. Modern evidence demonstrates that:
- Patients on MAO inhibitors have treatment-resistant depression with increased psychiatric risk that outweighs perioperative anesthetic risk 1
- Multiple case series and comparative studies confirm safety of both general and regional anesthesia without MAOI discontinuation 1, 2
- Severe adverse incidents are rare when proper precautions are followed 1
Essential Drug Avoidance
Absolutely contraindicated medications:
- Meperidine (pethidine) - can cause fatal serotonin syndrome; use alternative opioids 3, 4
- Indirect-acting sympathomimetics (ephedrine, amphetamines) - risk of hypertensive crisis 4
- Other serotonergic agents (tramadol, methadone, fentanyl in high doses) - increased serotonin syndrome risk 4
Safe Anesthetic Agents
Recommended opioids:
- Sufentanil, alfentanil, or remifentanil are safe alternatives to meperidine 3
- Standard fentanyl doses are generally safe, though it has mild serotonergic activity 4
Anesthetic maintenance:
- Volatile agents (isoflurane, sevoflurane, desflurane) are safe 3
- Propofol-based TIVA is acceptable 1
- Benzodiazepines (midazolam) for premedication and sedation are safe 1
Local anesthetics:
- Bupivacaine, prilocaine, and other local anesthetics are safe for regional techniques 1
Regional vs. General Anesthesia
Both techniques are safe when MAOIs are continued:
- Spinal and epidural anesthesia have been successfully performed without complications 1
- General anesthesia is equally safe with appropriate agent selection 3, 2
- Choice should be based on surgical requirements and patient factors, not MAOI therapy 1
Critical Perioperative Management
Hemodynamic stability is paramount:
- Maintain sympathetic homeostasis - avoid both hypotension and hypertension 1
- Have direct-acting vasopressors immediately available (phenylephrine, norepinephrine) - these are safe with MAOIs 1
- Avoid indirect-acting agents (ephedrine) that can precipitate hypertensive crisis 4
Monitoring requirements:
- Standard ASA monitoring (ECG, SpO2, NIBP, capnography) 4
- Consider processed EEG monitoring if using TIVA with neuromuscular blockade 4
- Vigilant cardiovascular monitoring given potential for hemodynamic instability 1
Specific Considerations by MAOI Type
Tranylcypromine has lower risk of pharmacokinetic drug interactions compared to phenelzine 1. However, all MAOIs require the same precautions regarding:
Multimodal Analgesia Strategy
Opioid-sparing techniques are particularly valuable:
- Regional nerve blocks with local anesthetics (bupivacaine) 1
- NSAIDs (etoricoxib, ketorolac) are safe 1
- Acetaminophen is safe 1
- Avoid tramadol due to serotonergic activity 4
Common Pitfalls to Avoid
- Never use meperidine - this is the most dangerous interaction 3, 4
- Do not use indirect sympathomimetics (ephedrine) for hypotension - use direct-acting agents instead 4, 1
- Do not discontinue MAOIs preoperatively unless psychiatric consultation determines the risk-benefit favors stopping 1, 2
- Avoid combining multiple serotonergic agents (high-dose fentanyl, tramadol, methadone) 4
- Patients with severe cardiovascular comorbidity require extra caution as this likely contributed to historical adverse events 1
Preoperative Assessment
Evaluate:
- Duration and indication for MAOI therapy (treatment-resistant depression indicates high relapse risk) 1
- Cardiovascular comorbidities (these are often contraindications to MAOIs and increase perioperative risk) 1
- Current psychiatric stability and risk of relapse if medication stopped 1
- Planned surgical procedure and anesthetic technique 1