Medications Used Before Cancer Treatment
For patients undergoing cancer treatment, antiemetic medications should be administered prophylactically before chemotherapy based on the emetogenic potential of the chemotherapy regimen to prevent nausea and vomiting. 1
Antiemetic Medications Based on Emetogenic Risk
High Emetogenic Risk Chemotherapy
- Three-drug combination recommended: 1
- NK1 receptor antagonist (aprepitant 125 mg PO day 1, then 80 mg days 2-3 or fosaprepitant 150 mg IV day 1)
- 5-HT3 antagonist (ondansetron, granisetron, dolasetron, or palonosetron) given before chemotherapy
- Dexamethasone 12 mg PO/IV day 1, then 8 mg daily days 2-4
- Optional additions: 1
- Lorazepam 0.5-2 mg PO/IV/sublingual every 4-6 hours PRN
- H2 blocker or proton pump inhibitor
Moderate Emetogenic Risk Chemotherapy
- Two-drug combination recommended: 1
- 5-HT3 antagonist (ondansetron 16-24 mg PO or 8-12 mg IV, granisetron 2 mg PO or 1 mg IV, dolasetron 100 mg PO, or palonosetron 0.25 mg IV)
- Dexamethasone 8 mg PO/IV day 1
- Consider adding NK1 receptor antagonist for select patients receiving carboplatin or other moderate-risk agents 1
Low Emetogenic Risk Chemotherapy
- Single agent recommended: 1
- Dexamethasone 8-12 mg PO/IV day 1
- Or metoclopramide 10-40 mg PO/IV every 4-6 hours PRN
- Or prochlorperazine 10 mg PO/IV every 4-6 hours PRN
Minimal Emetogenic Risk Chemotherapy
- No routine prophylaxis recommended 1
Growth Factor Support
- Granulocyte colony-stimulating factor (G-CSF) is administered prophylactically before or after chemotherapy to reduce the risk of febrile neutropenia and related complications 1
- Indications for G-CSF prophylaxis: 2, 3
- Chemotherapy regimens with >20% risk of febrile neutropenia
- Regimens with 10-20% risk plus patient risk factors (age ≥65, poor performance status, prior neutropenic fever)
- Dose-dense or dose-intense chemotherapy regimens where maintaining dose intensity is important for survival
- G-CSF significantly reduces days of neutropenia, antibiotic use, and hospitalization 4, 5
Premedications for Hypersensitivity Reactions
- For patients receiving taxanes, platinum compounds, or monoclonal antibodies: 1
- Dexamethasone (often given as part of antiemetic regimen)
- H1 antagonists (diphenhydramine 25-50 mg)
- H2 antagonists (famotidine, ranitidine)
Special Considerations for People Living with HIV
- Antiemetic medications can be safely administered to patients with HIV receiving cancer treatment 1
- For patients with HIV: 1
- Continue antiretroviral therapy during cancer treatment
- Limit prolonged steroid use for antiemetic therapy to reduce risk of opportunistic infections
- Consider drug interactions between antiretrovirals and antiemetics
Breakthrough and Anticipatory Nausea/Vomiting
- For breakthrough symptoms: 1
- Add olanzapine if not used prophylactically
- Consider adding agent from different class (lorazepam, dopamine antagonist, cannabinoid)
- For anticipatory nausea/vomiting: 1
- Lorazepam 1 mg PO the night before and morning of chemotherapy
- Consider behavioral modification techniques
Important Clinical Considerations
- Antiemetic regimens should be chosen based on the drug with highest emetic risk in the chemotherapy regimen 1
- Protection must cover the entire period of risk (3 days for high risk, 2 days for moderate risk agents) 1
- Oral and IV antiemetic formulations have equivalent efficacy 1
- For multiday chemotherapy regimens, antiemetics should be given before treatment each day and continued for 2 days after completion 1
- Palonosetron is preferred among 5-HT3 antagonists for highly emetogenic chemotherapy due to its longer half-life 1, 6
Common Pitfalls to Avoid
- Underdosing antiemetics for highly emetogenic regimens (must use three-drug combination) 1
- Using PRN (as needed) dosing instead of scheduled administration 1
- Failing to continue prophylaxis through the entire period of risk 1
- Not adjusting antiemetic strategy after breakthrough nausea/vomiting in previous cycles 1
- Overlooking patient-specific risk factors that may increase emesis risk 1