Should a patient on a prednisone taper (scheduled 60 mg today) receive 12 mg dexamethasone as pre‑chemotherapy anti‑emetic and skip the 60 mg prednisone dose, then resume the taper the following day?

Managing Concurrent Prednisone Taper and Pre-Chemotherapy Dexamethasone

The patient should skip the 60 mg prednisone dose on the day of chemotherapy (when receiving 12 mg dexamethasone pre-treatment) and resume the prednisone taper the following day to avoid excessive cumulative corticosteroid exposure and associated adverse effects. 1

Rationale for Holding the Prednisone Dose

• Dexamethasone 12 mg is approximately equivalent to prednisone 80 mg in anti-inflammatory potency (using the standard conversion of 1 mg dexamethasone ≈ 6.67 mg prednisone), meaning the patient would receive a total corticosteroid load equivalent to ~140 mg prednisone if both doses were given on the same day. 2

• The American Society of Clinical Oncology recommends 12 mg dexamethasone on day 1 for highly emetogenic chemotherapy as part of standard antiemetic prophylaxis, which already provides substantial corticosteroid coverage for that 24-hour period. 3

• Short-term antiemetic corticosteroid courses (3–4 days per cycle) are associated with minimal risk of clinically significant adverse events, but excessive same-day dosing increases the risk of hyperglycemia, mood disturbances, and insomnia without additional therapeutic benefit. 1

Practical Implementation Algorithm

1. On the day of chemotherapy: Administer only the 12 mg dexamethasone as pre-chemotherapy antiemetic prophylaxis; hold the scheduled 60 mg prednisone dose. 3

2. Days 2–4 post-chemotherapy: Follow the standard antiemetic dexamethasone schedule (typically 8 mg daily for highly emetogenic regimens); continue to hold the prednisone taper during these days. 3

3. Day 5 onward: Resume the prednisone taper at the next scheduled dose in the tapering sequence (which would be the dose scheduled for day 5, not returning to 60 mg). 2

Key Considerations for Corticosteroid Overlap

• The dexamethasone used for antiemetic prophylaxis provides sufficient corticosteroid coverage to prevent adrenal insufficiency during the chemotherapy cycle, eliminating the need for concurrent prednisone dosing during days 1–4. 1

• Patients receiving corticosteroids for non-palliative indications (such as antiemesis or as part of a taper) showed survival comparable to those not receiving steroids, confirming that short-term protocol-driven corticosteroid use does not compromise oncologic outcomes. 1

• When aprepitant or fosaprepitant (NK₁ antagonists) are co-administered, dexamethasone doses are already reduced by 40–50% due to CYP3A4 inhibition, which increases dexamethasone exposure; adding prednisone would further compound this effect. 1

Common Pitfalls to Avoid

• Do not simply add the prednisone dose on top of the dexamethasone, as this creates excessive corticosteroid exposure equivalent to >140 mg prednisone, increasing the risk of acute hyperglycemia, psychiatric symptoms, and gastric irritation without improving antiemetic efficacy. 2

• Do not restart the prednisone taper at 60 mg after chemotherapy; instead, resume at the next scheduled dose in the tapering sequence to maintain the intended gradual reduction. 2

• Ensure the patient understands that the dexamethasone is temporarily replacing (not supplementing) their prednisone during the chemotherapy cycle, and provide written instructions specifying when to resume the prednisone taper. 2

• Monitor blood glucose closely in diabetic patients, as the combined corticosteroid exposure (even when properly sequenced) can cause transient hyperglycemia requiring temporary insulin adjustment. 1