How should I manage a patient who develops a scratchy throat during the fourth infusion of a vendor‑supplied medication, assuming they are otherwise stable?

Management of Scratchy Throat During Fourth Infusion

Stop or slow the infusion immediately and provide symptomatic treatment with antihistamines (diphenhydramine 50 mg IV) and H2 blockers (ranitidine 50 mg IV), then resume at half the rate once symptoms resolve. 1

Immediate Assessment and Action

A scratchy throat during infusion represents a Grade 1-2 infusion reaction (mild to moderate severity). This symptom is specifically recognized in the ESMO guidelines as "throat irritation," particularly common with agents like daratumumab where it occurs in 40-50% of patients 1.

Step-by-Step Management Algorithm:

1. Stop or significantly slow the infusion rate immediately 1

   • Do not wait to see if symptoms worsen
   • Maintain IV access

2. Assess for progression to more severe symptoms:

   • Check vital signs (blood pressure, pulse, oxygen saturation)
   • Look for dyspnea, bronchospasm, or hypoxia
   • Evaluate for angioedema or facial swelling
   • Monitor for hypotension or tachycardia

3. Administer symptomatic treatment:

   • Diphenhydramine 50 mg IV plus ranitidine 50 mg IV 1
   • Consider corticosteroids (methylprednisolone 1-2 mg/kg IV) if symptoms persist 1

4. Once patient is stable and symptoms resolve:

   • Resume infusion at 50% of the previous rate 1
   • Titrate upward to tolerance while monitoring closely
   • Continue observation throughout remainder of infusion

Critical Considerations

This is the fourth infusion, which is important because:

• Most infusion reactions occur during the first or second infusion (82-95% with some agents) 1
• A reaction at the fourth infusion suggests either cumulative sensitization or inadequate premedication
• The patient has tolerated three prior infusions, making severe anaphylaxis less likely but not impossible

Common pitfall: Dismissing isolated throat symptoms as minor. Throat irritation can be the first sign of laryngeal edema or bronchospasm, which can rapidly progress to airway compromise 2.

For Subsequent Infusions

Implement premedication protocol before the next infusion:

• Oral antipyretics (paracetamol 650-1000 mg) 1 hour before infusion
• Oral or IV antihistamine (diphenhydramine 25-50 mg)
• Consider adding corticosteroid premedication (methylprednisolone 100 mg IV) 1

When to Escalate

Permanently discontinue if:

• Grade 3-4 reaction develops (severe dyspnea, hypotension, bronchospasm requiring aggressive intervention)
• Grade 3 reaction recurs at subsequent infusion despite premedication 1

Do NOT:

• Continue infusion at the same rate hoping symptoms will resolve
• Assume this is "just anxiety" because previous infusions were tolerated
• Delay treatment waiting for physician assessment—nurses can and should intervene immediately

The key principle is that mild symptoms require immediate intervention to prevent progression, and successful rechallenge depends on slower infusion rates with adequate premedication 1, 2.