Dexamethasone for Nausea and Vomiting
Yes, dexamethasone is highly effective for preventing both acute and delayed chemotherapy-induced nausea and vomiting, and is recommended as a standard antiemetic agent across multiple emetic risk categories by ASCO and MASCC guidelines. 1
Evidence-Based Efficacy
Moderate Emetic Risk Chemotherapy
Dexamethasone is the preferred agent for preventing delayed emesis (days 2-5) in patients receiving moderately emetogenic chemotherapy, with MASCC guidelines specifically recommending it over 5-HT3 antagonists 1
A phase III randomized controlled trial demonstrated that dexamethasone was superior to placebo in decreasing delayed emesis (87% vs 77%, P < 0.02) 1
When compared head-to-head with ondansetron, dexamethasone showed equivalent control of emesis and quality of life, with significantly better control of delayed nausea (87% vs 72%, P = 0.003) 2
A meta-analysis of 32 RCTs involving 5,613 patients demonstrated that dexamethasone was superior to placebo for complete protection from acute emesis (odds ratio 2.22; 95% CI, 1.89 to 2.60) and delayed emesis (odds ratio 2.04; 95% CI, 1.63 to 2.56) 1
High Emetic Risk Chemotherapy
Dexamethasone is a mandatory component of the three-drug regimen (5-HT3 antagonist + dexamethasone + NK1 receptor antagonist) for highly emetogenic chemotherapy 1
For delayed emesis prevention after highly emetogenic chemotherapy, dexamethasone combined with aprepitant is superior to dexamethasone alone (21% vs 36% with emesis, P < 0.001) 1
Low Emetic Risk Chemotherapy
Patients receiving low-risk agents can be offered dexamethasone before the first dose of chemotherapy, though the decision should be based on the specific chemotherapy regimen 1
This recommendation is extrapolated from the substantial evidence in moderate to highly emetic chemotherapy, as no RCTs exist specifically for low emetic risk regimens 1
Practical Dosing Algorithms
For Moderately Emetogenic Chemotherapy (Non-AC Regimens)
- Day 1: Dexamethasone 8 mg IV or oral before chemotherapy 1, 3
- Days 2-3: Dexamethasone 8 mg oral daily (though single-day dosing may be non-inferior for non-anthracycline/cyclophosphamide regimens) 3
For Anthracycline + Cyclophosphamide Regimens
- Day 1: Dexamethasone 8 mg IV + 5-HT3 antagonist + aprepitant 125 mg oral 1
- Days 2-3: Aprepitant 80 mg oral (dexamethasone dosing adjusted when using aprepitant) 1
For Highly Emetogenic Chemotherapy
- Day 1: Dexamethasone dose (typically 12 mg) + 5-HT3 antagonist + NK1 antagonist 1
- Days 2-4: Dexamethasone 8 mg oral twice daily on days 3-4 when using fosaprepitant 150 mg IV 1
Important Caveats
Side Effect Profile
Dexamethasone causes significant side effects that may impact quality of life: insomnia (45%), indigestion/epigastric discomfort (27%), agitation (27%), increased appetite (19%), weight gain (16%), and acne (15%) 4
These side effects may outweigh benefits when used with moderately emetogenic chemotherapy, particularly in multi-day regimens 4
Combination Therapy Considerations
Adding 5-HT3 antagonists to dexamethasone for delayed emesis does not improve efficacy and increases constipation (92% vs 87% control, not significant) 1
For acute emesis with moderately emetogenic chemotherapy, combining granisetron with dexamethasone achieves 92.6% complete protection from vomiting versus 70.6% with dexamethasone alone (P < 0.001) 5