HaematologyTier 1Approach to a presentation

Chemotherapy side effects, such as mucositis, nausea, pain, and vomiting

Red flags

  • Fever in a patient on/recently post chemo - treat as febrile neutropenia until proven otherwise, regardless of how well they look
  • Severe mucositis -> odynophagia -> inability to swallow secretions/medication -> aspiration, dehydration risk
  • Intractable vomiting -> electrolyte derangement, AKI, non-adherence to oral anti-cancer therapy
  • New neuropathic pain pattern - platinum/vinca/taxane peripheral neuropathy, can be dose-limiting
  • Severe abdominal pain + neutropenia -> neutropenic enterocolitis (typhlitis) - surgical emergency mimic

Differential by mechanism

Nausea/vomiting
  • Acute (<24h) - direct chemoreceptor trigger zone stimulation (5-HT3 mediated)
  • Delayed (24h-5 days) - substance P/NK1 mediated, esp. cisplatin
  • Anticipatory - conditioned response from prior poorly-controlled cycles
Mucositis
  • Direct cytotoxic damage to rapidly-dividing GI epithelium -> ulceration, esp. 5-FU, methotrexate, high-dose conditioning regimens
  • Superimposed infection (Candida, HSV) on damaged mucosa - do not assume purely chemotherapy-related if atypical/worsening
Pain
  • Mucositis-related, tumour-related, or treatment-related neuropathy (platinum, vincristine, taxanes, bortezomib)
  • Bone pain post G-CSF (marrow expansion) - common, often mistaken for disease progression

Focused history

  • Regimen and day post-chemo (emetogenic potential and mucositis risk are regimen-specific)
  • Oral intake/hydration, ability to swallow tablets (affects oral anti-emetic/analgesic choice)
  • Fever, rigors - triggers febrile neutropenia pathway regardless of other symptoms
  • Pre-existing anti-emetic regimen and adherence
  • Baseline bowel habit (chemo causes constipation as often as diarrhoea depending on agent + concurrent opioids)

Focused examination

  • Vitals - fever changes the entire management pathway
  • Oral cavity - mucositis grading (erythema -> ulceration -> unable to eat)
  • Hydration status, abdominal exam (rebound/guarding - consider typhlitis if neutropenic)
  • Neurological exam if neuropathy suspected - distal, symmetric, sensory > motor typically

Investigation strategy

  • FBE, UEC, corrected calcium/magnesium - vomiting/poor intake causes derangement
  • Blood cultures + full sepsis work-up if febrile (see febrile neutropenia)
  • CT abdomen if severe pain + neutropenia - excludes typhlitis/perforation
  • Oral swab for HSV/Candida if mucositis atypical or worsening despite supportive care

Management

By presenting problem

Nausea/vomiting - matched to emetogenic risk of the regimen

  • High emetogenic risk - 5-HT3 antagonist + dexamethasone + NK1 antagonist (aprepitant/fosaprepitant) +/- olanzapine
  • Moderate risk - 5-HT3 antagonist + dexamethasone
  • Low risk - single agent (dexamethasone or 5-HT3 antagonist) or none
  • Breakthrough - add agent from a different class (e.g. metoclopramide, olanzapine); olanzapine increasingly used, effective across acute/delayed/breakthrough
  • Anticipatory - benzodiazepine before subsequent cycles, behavioural techniques

Mucositis

  • Oral hygiene (soft brush, saline/bicarbonate rinses), cryotherapy during infusion for 5-FU/high-dose melphalan (reduces severity)
  • Analgesia - topical (lignocaine) -> systemic opioid if severe (grade 3-4)
  • Treat superimposed candida (nystatin/fluconazole) or HSV (aciclovir) if identified
  • IV fluids/nutrition support if oral intake inadequate

Pain

  • WHO analgesic ladder, adjuncts for neuropathic pain (gabapentinoids, duloxetine)
  • Dose-modify/hold the causative neurotoxic agent if progressive neuropathy - prevention (dose adjustment) more effective than treatment once established

Constipation/diarrhoea

  • Proactive laxative with vinca alkaloids/opioid co-prescription
  • Loperamide for chemo-induced diarrhoea (not if febrile/neutropenic with suspected infective colitis)

Traps

  • Attributing fever to "just the chemo" - always exclude neutropenic sepsis first
  • Treating diarrhoea with loperamide in a febrile neutropenic patient before excluding infective/typhlitis causes
  • Under-treating anticipatory nausea - prevention from cycle 1 is easier than reversing a conditioned response
  • Missing typhlitis - severe abdominal pain + neutropenia + fever is a surgical/haematology emergency, not routine gastroenteritis

Talk track

  • "Any fevers or rigors?" -> if yes, this becomes a febrile neutropenia work-up first
  • "Which chemo, which day are you post-cycle?" -> defines expected symptom window and emetogenic/mucositis risk
  • "Can you keep fluids and medications down?" -> determines route (oral vs parenteral) and admission threshold
  • "Any numbness, tingling, or pain in your hands/feet?" -> screens for dose-limiting neuropathy

8 of 8 sections written · drafted 2026-09-13