12-phase flow (10)

1. 1FRAME
   MAOI–tyramine crisis = irreversible MAO-A/B inhibition + dietary tyramine (aged cheese, cured meats, etc.) OR sympathomimetic medication → tyramine-driven NE flood from sympathetic terminals → severe HTN crisis with severe occipital headache + tachy + diaphoresis within 30 min – 2 h. Pharmacology pivot: PHENTOLAMINE 5 mg IV q5-15 min titrate (alpha-blocker, cornerstone) OR nicardipine IV (autoregulation-aware alternative); AVOID β-blocker monotherapy (unopposed alpha vasoconstriction worsens HTN); AVOID meperidine (can trigger hyperthermic + serotonin reactions in MAOI); SSRI 14-d washout required before/after irreversible MAOI.
   inputs: sbp, dbp, heart_rate, maoi_medication_history, dietary_or_sympathomimetic_trigger_history
   advance: MAOI-tyramine etiology confirmed by history (med + trigger) + clinical features (occipital headache + HTN crisis)
2. 2ENTRY
   Recognize cheese-reaction toxidrome (severe occipital headache + HTN crisis + tachy + diaphoresis after MAOI + tyramine/sympathomimetic exposure); IV access + cardiac monitor + immediate phentolamine IV bolus
   inputs: age, sbp, temperature
   advance: phentolamine IV ready + ECG done + neuro exam done
3. 3CONTEXT
   MAOI medication details (which agent, dose, duration); trigger details (specific food/drink, timing of intake, OR sympathomimetic medication); concomitant medications (SSRI, SNRI, tramadol, meperidine, dextromethorphan, decongestants, OTC cold meds, supplements like ephedra, St John's wort); prior tyramine reactions; comorbidities (depression, treatment-resistant depression, refractory bulimia); medication adherence + patient education history
   inputs: age, maoi_medication_history
   advance: comprehensive med rec + trigger identified + interaction screen done
4. 4RED_FLAGS
   ICH (cheese reactions can cause ICH — case reports of fatal ICH per Wimbiscus 2010); aortic dissection (severe HTN risk factor); MI (NE surge demand ischemia in elderly with CAD); pulmonary edema (acute LV strain); concurrent serotonin syndrome (MAOI + SSRI/meperidine overlap — clonus + hyperthermia + autonomic features); hyperthermia >40°C (suggests serotonin syndrome overlap)
   inputs: sbp, temperature, headache_quality_assessment, neurologic_exam
   actions: htn_emergency
   advance: RED flags screened + life-threats addressed + ICH/dissection/MI/serotonin-syndrome differentiated
5. 5INITIAL_WORKUP
   ECG (QTc, ischemia, demand strain); troponin (q3-6h × 2 if chest pain or elderly with CAD); CBC + BMP + Mg + lactate; CT head non-con (exclude ICH given severe headache + HTN); CTA chest if dissection concern (back pain, BP differential, pulse deficit); UA for myoglobin if rhabdo; CXR (acute pulmonary edema)
   inputs: ecg_12_lead, troponin, creatinine, neurologic_exam
   actions: panel.cardiac, panel.renal
   advance: workup documented + ICH/dissection/MI/serotonin-syndrome ruled in/out
6. 6BRANCHING_WORKUP
   If ICH → AHA/ASA 2022 ICH pathway + nicardipine target SBP 130-140; if dissection → CTA + emergency CT surgery; if MI → cardiology + ACS pathway (avoid β-blocker monotherapy); if serotonin syndrome overlap → cyproheptadine + STOP serotonergic agents + route to serotonin-syndrome engine
   advance: syndrome-specific pathway activated if needed
7. 7TREATMENT
   STEP 1 — Phentolamine 5 mg IV bolus q5-15 min titrate to SBP <160 within 1-2 h (cornerstone — alpha-blocker reverses NE surge); typical total 5-20 mg cumulative. STEP 2 — Nicardipine IV 5 mg/h titrate to max 15 mg/h as alternative or adjunct (autoregulation-aware, useful if phentolamine unavailable or insufficient). STEP 3 — IV fluids (modest crystalloid; avoid overload). STEP 4 — Antiemetic for N/V (metoclopramide caution — extrapyramidal; ondansetron generally OK in tyramine crisis but caution in serotonin overlap). STEP 5 — Pain control (acetaminophen for headache; AVOID meperidine; opioids generally OK if non-meperidine). STEP 6 — If tachycardia persists after phentolamine + BP control, can add esmolol or labetalol cautiously AFTER alpha-blockade (similar logic to pheochromocytoma — alpha first then beta). AVOID β-blocker monotherapy (unopposed alpha worsens HTN; classic teaching from pheochromocytoma + cocaine extends to tyramine crisis). AVOID meperidine (can cause severe hyperthermic + hypertensive reactions in MAOI patients per FDA boxed warning). AVOID nitroprusside (cyanide accumulation if prolonged use + autoregulation issues).
   inputs: sbp, dbp, heart_rate
   advance: phentolamine titrated + BP at target SBP <160 + headache improving + no new neuro deficit
8. 8DISPOSITION
   ICU / step-down for q15 min BP + telemetry minimum 12-24 h (BP can rebound; concurrent organ damage rule-out); admit minimum 24 h for observation + dietary/medication education + safer-alternative regimen consideration
   advance: monitored bed assigned + 24-h observation plan
9. 9MONITORING
   Continuous ECG + telemetry; q15-30 min BP; serial troponin q3-6h × 2 if elderly or CAD; serial neuro exam q2h × 12 h; pain score; UOP
   inputs: sbp, heart_rate
   actions: panel.cardiac
   advance: BP at target + no organ damage + headache resolved + dietary/medication education completed
10. 10FOLLOWUP
    COMPREHENSIVE TYRAMINE-RESTRICTED DIET EDUCATION (handout + dietitian consult; high-tyramine foods to AVOID: aged cheeses, cured meats, fava beans, soy sauce, draft beer, sauerkraut, fermented soy, miso, tempeh, marmite/vegemite, tap beer; safe-in-moderation: pasteurized cheese, fresh meat, processed cheese); MEDICATION INTERACTION LIST education (AVOID sympathomimetics — pseudoephedrine, phenylephrine, ephedra, OTC cold meds, decongestants; AVOID meperidine — FDA boxed warning; AVOID SSRI/SNRI/tramadol/dextromethorphan during MAOI + 14-d washout); psychiatry consultation re: continuing MAOI vs alternative (consider switch to MAOI-B selective transdermal selegiline if low-dose tolerated, OR switch to other antidepressant class with appropriate washout); if MAOI required to continue, dietitian referral + medication card carried + family education + MedicAlert bracelet; outpatient PCP + psychiatry follow-up within 1-2 weeks
    advance: dietary education completed + medication card issued + psychiatry follow-up booked + safer regimen considered