化療引起噁心嘔吐的止吐處置

Buzzwords → Dx

Emetogenic Risk Categories

• High (>90 %): cisplatin, AC, mechlorethamine, streptozocin, dacarbazine, BCNU high-dose.
• Moderate (30-90 %): carboplatin, cyclophosphamide ≥1500 mg/m², doxorubicin, oxaliplatin, ifosfamide, irinotecan, methotrexate ≥250 mg/m².
• Low (10-30 %): docetaxel, paclitaxel, etoposide, gemcitabine, fluorouracil, mitomycin, topotecan.
• Minimal (<10 %): bevacizumab, rituximab, vinca alkaloids, bleomycin.

Treatment Algorithm

flowchart TD
  A[Chemotherapy planned] --> B[Assess emetogenic risk]
  B --> C{Risk}
  C -- High >90% --> D[5-HT3 + dex + NK1 + olanzapine<br>(or 5-HT3 + dex + NK1 alone)]
  C -- Moderate 30-90% --> E[5-HT3 + dex<br>+ NK1 if extra risk factors]
  C -- Low 10-30% --> F[5-HT3 OR dex alone]
  C -- Minimal <10% --> G[Pre-medication usually unnecessary; on-demand]
  D --> H[+ Olanzapine 5-10 mg × 4 d for delayed + breakthrough<br>or aprepitant in delayed phase]
  E --> H
  H --> I{Breakthrough nausea?}
  I -- yes --> J[Add: olanzapine, prochlorperazine, metoclopramide, lorazepam]
  I -- anticipatory --> K[Pre-chemo lorazepam<br>cognitive-behavioral therapy]

Pearls / Pitfalls

• Delayed CINV is hardest to control — driven by substance P / NK1 — NK1 antagonist + olanzapine + extended dexamethasone.
• Olanzapine 10 mg × 4 d dramatically reduces both acute and delayed CINV (multiple trials, NEJM 2016 Navari) — sedation main AE.
• 5-HT3 antagonists can prolong QTc — palonosetron has lower risk than ondansetron; check ECG in long-QT patients.
• Dexamethasone hyperglycemia + insomnia + steroid-induced psychosis — limit to scheduled days; taper if prolonged.
• NK1 antagonist drug-drug interactions: aprepitant inhibits CYP3A4 → ↑ levels of dexamethasone, warfarin, oral contraceptives. Fosaprepitant single IV dose.
• Anticipatory CINV is conditioned response — best prevented by good control of acute CINV from cycle 1.
• Cisplatin emesis prevention is the historic high-bar test of antiemetic efficacy.
• Cannabinoids (dronabinol, nabilone) for refractory CINV — appetite stimulation bonus in palliative setting.
• Marijuana / CBD for CINV — limited rigorous data; legal varies by region.
• Breakthrough vs anticipatory: breakthrough during/after chemo cycle; anticipatory before subsequent cycle (Pavlovian conditioning).

Cross-references

• Drug Regimens — antiemetic protocols
• Pain — opioid-induced nausea
• Infection ppx context

相關題目

• Q-202 — Highly emetogenic chemo prophylaxis
• Q-203 — Anticipatory CINV management
• Q-204 — Aprepitant — drug-drug interactions

Sources