What is the best approach to manage vomiting in children after their first chemotherapy session?

Management of Vomiting in Children After First Chemotherapy Session

For children experiencing vomiting after their first chemotherapy session, a three-drug combination of a 5-HT3 receptor antagonist, dexamethasone, and aprepitant is strongly recommended for those who received high-emetic-risk chemotherapy, while a two-drug combination of a 5-HT3 receptor antagonist and dexamethasone is recommended for moderate-emetic-risk chemotherapy. 1

Assessment of Chemotherapy Emetogenicity

First, determine the emetogenic risk of the chemotherapy regimen administered:

• High-emetic-risk: Includes cisplatin ≥50 mg/m², and certain combination regimens
• Moderate-emetic-risk: Includes lower doses of cisplatin, ifosfamide, and certain other agents
• Low-emetic-risk: Includes certain lower-intensity chemotherapeutics
• Minimal-emetic-risk: Includes agents with very low likelihood of causing emesis

Treatment Algorithm Based on Emetogenic Risk

For High-Emetic-Risk Chemotherapy

1. First-line approach:

   • 5-HT3 receptor antagonist (e.g., ondansetron 0.15 mg/kg IV or palonosetron 20 μg/kg IV)
   • Dexamethasone (dose reduced by 50% if using aprepitant)
   • Aprepitant (for children ≥6 months of age)

2. If aprepitant cannot be administered:

   • 5-HT3 receptor antagonist
   • Dexamethasone 1

3. If dexamethasone cannot be administered:

   • Palonosetron
   • Aprepitant 1

For Moderate-Emetic-Risk Chemotherapy

1. Standard approach:

   • 5-HT3 receptor antagonist
   • Dexamethasone 1

2. If dexamethasone cannot be administered:

   • 5-HT3 receptor antagonist
   • Aprepitant 1

For Low-Emetic-Risk Chemotherapy

• Single agent: Ondansetron or granisetron 1

For Minimal-Emetic-Risk Chemotherapy

• No routine antiemetic prophylaxis recommended 1

Specific Medication Dosing

5-HT3 Receptor Antagonists

• Ondansetron:

  • Ages 12-17: 8 mg IV/PO 30 minutes before chemotherapy, then 8 mg 8 hours later, followed by 8 mg twice daily for 1-2 days
  • Ages 4-11: 4 mg IV/PO 30 minutes before chemotherapy, then 4 mg at 4 and 8 hours, followed by 4 mg three times daily for 1-2 days 2
  • Note: Higher weight-based doses may be required in children compared to adults 1

• Palonosetron:

  • 20 μg/kg IV (single dose) 30 minutes before chemotherapy 1
  • Has shown superior control of both acute and delayed emesis compared to other 5-HT3 antagonists 1, 3

Corticosteroids

• Dexamethasone:
  • Standard dose: Reduce by 50% when used with aprepitant 3, 4
  • Administer 30 minutes before chemotherapy 3

NK1 Receptor Antagonists

• Aprepitant (for children ≥12 years who can swallow capsules):
  • Day 1: 125 mg PO 1 hour before chemotherapy
  • Days 2-3: 80 mg PO once daily 4

Management of Breakthrough Vomiting

If vomiting occurs despite prophylaxis:

1. Add a dopamine antagonist:

   • Metoclopramide 20-30 mg PO/IV every 6 hours
   • Prochlorperazine 10-20 mg PO/IV every 6 hours (for older children) 3

2. Consider adding:

   • Lorazepam 1-2 mg PO/IV every 6 hours for anxiety component 3

3. Switch to IV administration if the child is actively vomiting 3

Important Clinical Considerations

• Timing is crucial: Administer antiemetics 30-60 minutes before chemotherapy 3
• Duration of therapy: Continue antiemetics for at least 24 hours after chemotherapy, and up to 2-3 days for highly emetogenic regimens 1, 3
• Route of administration: Use IV route if the child is actively vomiting 3
• Monitoring: Assess the child's response to antiemetics and adjust therapy as needed

Evidence Strength and Considerations

The evidence supporting the use of 5-HT3 antagonists in combination with dexamethasone is strong, with multiple studies demonstrating efficacy 1, 5. The addition of aprepitant has been shown to significantly reduce moderate-to-severe vomiting (38% vs 72% in the first 24 hours) in children receiving high-emetic-risk chemotherapy 1.

Palonosetron may be more effective than ondansetron for controlling both acute and delayed emesis, as demonstrated in a non-inferiority trial that showed potential superiority from 0 to 120 hours 1.

Early and effective control of acute emesis is critical, as it correlates strongly with control of delayed emesis 6. Failure to control vomiting during the first 24 hours has a high predictive value for delayed emesis in the same cycle.

By following this evidence-based approach, the majority of children can achieve good control of chemotherapy-induced vomiting, significantly improving their quality of life during cancer treatment.