How should hydroxyurea (hydroxycarbamide) be managed in the post-operative period after surgery?

Management of Hydroxyurea in the Post-Operative Period

Hydroxyurea (hydroxycarbamide) should be continued throughout the perioperative period for patients with myeloproliferative neoplasms, unless there are unique contraindications expressed by the surgical team. 1

General Principles for Perioperative Management

Hydroxyurea is a cytoreductive agent commonly used in myeloproliferative disorders and sickle cell disease. The management approach differs based on the underlying condition:

For Myeloproliferative Neoplasms:

• Continue hydroxyurea throughout the perioperative period 1
• No need to interrupt therapy before or after surgery
• Monitor complete blood counts weekly to ensure adequate hematological parameters

For Sickle Cell Disease:

• Hydroxyurea can be continued perioperatively with careful monitoring 2
• Patients on hydroxyurea may require fewer transfusions compared to those not on hydroxyurea 2
• Monitor for potential complications such as acute chest syndrome 2

Specific Perioperative Considerations

Pre-operative Management:

• Continue hydroxyurea at the same dose up to the day of surgery 1
• Ensure adequate hydration to prevent complications, especially in patients with sickle cell disease 1
• For patients with myeloproliferative disorders, ensure hematocrit <45% prior to elective surgery 1

Intra-operative Management:

• No specific dose adjustments are required during surgery
• Maintain normothermia to prevent complications, particularly in sickle cell patients 1
• Ensure adequate oxygenation and avoid hypotension 1

Post-operative Management:

• Resume hydroxyurea at the same pre-operative dose as soon as oral medications can be tolerated 1
• Monitor complete blood counts weekly to assess for myelosuppression 3
• For patients with renal impairment (CrCl <60 mL/min), reduce the dose of hydroxyurea 3
• Ensure adequate hydration and monitor fluid balance 1

Special Considerations

Renal Function:

• Hydroxyurea exposure increases by 64% in patients with CrCl <60 mL/min 3
• Dose reduction is necessary for patients with impaired renal function or end-stage renal disease 3

Monitoring Parameters:

• Weekly complete blood counts to monitor for myelosuppression 3
• Signs of infection or bleeding 3
• Signs of hemolytic anemia 3
• Wound healing and surgical site complications

Potential Complications:

• Myelosuppression (most common)
• Delayed wound healing
• Increased risk of infection
• Potential for acute chest syndrome in sickle cell patients 2

Contraindications to Continuing Hydroxyurea

While hydroxyurea can generally be continued, consider temporary discontinuation if:

• Severe myelosuppression develops
• Significant impairment in renal function occurs post-operatively
• The surgical team specifically requests discontinuation due to concerns about wound healing
• Severe post-operative infection develops

Resuming Treatment After Temporary Discontinuation

If hydroxyurea was temporarily discontinued:

• Resume when oral medications can be safely administered
• Consider starting at a lower dose if there are concerns about myelosuppression
• Gradually increase to pre-operative dose while monitoring blood counts
• For patients with myeloproliferative neoplasms, aim to resume as soon as possible to maintain disease control 1

The evidence strongly supports continuing hydroxyurea throughout the perioperative period in most patients, with appropriate monitoring and dose adjustments based on renal function and blood counts.