Is hydroxyurea (Hydrea) contraindicated post-surgery?

Hydroxyurea Use in the Perioperative Period

Hydroxyurea can be continued throughout the perioperative period in most cases, unless there are specific contraindications expressed by the surgical team. 1

Perioperative Management Guidelines

The National Comprehensive Cancer Network (NCCN) guidelines specifically address the use of hydroxyurea during the perioperative period for patients with myeloproliferative neoplasms:

• Cytoreductive therapy, including hydroxyurea, can be continued throughout the perioperative period in most cases 1
• Blood counts should be controlled for at least 3 months before elective surgery (normalization or near-normalization of CBC) 1

Considerations for Different Patient Populations

Patients with Sickle Cell Disease

• Hydroxyurea has been shown to reduce perioperative transfusion requirements in children with sickle cell anemia 2
• Children taking hydroxyurea required substantially fewer transfusions compared to those not taking hydroxyurea in the perioperative period 2
• Both groups had low complication rates, suggesting hydroxyurea does not increase perioperative risks 2

Patients with Myeloproliferative Neoplasms

• Continuing hydroxyurea perioperatively helps maintain hematologic control, which is crucial for reducing thrombotic risk 1
• For patients with polycythemia vera, maintaining hematocrit <45% is important to reduce thrombotic complications 1

Potential Concerns and Monitoring

Wound Healing

• Recent evidence suggests hydroxyurea may impair wound healing in some patients 3
• Higher risk for wound disruption, wound infection, and recurrent sepsis has been observed in patients on hydroxyurea with burn injuries 3
• Monitor surgical wounds closely in patients continuing hydroxyurea perioperatively

Cutaneous Adverse Events

• Hydroxyurea can cause cutaneous adverse events including leg ulcers 4, 5
• If leg ulcers or other mucocutaneous manifestations develop postoperatively, consider discontinuing hydroxyurea 4

Algorithm for Perioperative Management of Hydroxyurea

1. Preoperative Assessment:

   • Ensure adequate blood count control (normal or near-normal CBC) for at least 3 months before elective surgery 1
   • Evaluate for existing skin lesions or ulcers that might contraindicate continued use

2. During Surgery:

   • Continue hydroxyurea unless specifically contraindicated by the surgical team 1
   • Consider the nature of the surgery and risk of wound healing complications

3. Postoperative Management:

   • Continue monitoring CBC regularly
   • Inspect surgical wounds frequently for signs of poor healing
   • If wound healing complications occur, consider discontinuing hydroxyurea 4
   • Resume normal dosing schedule when appropriate

When to Discontinue Hydroxyurea Perioperatively

Consider discontinuation if:

• The surgical team specifically requests discontinuation
• Patient develops leg ulcers or other mucocutaneous manifestations 4
• Poor wound healing is observed postoperatively 3
• Severe cytopenias develop (ANC <1.0 × 10^9/L, platelets <100 × 10^9/L, or hemoglobin <10 g/dL) 1, 4

In conclusion, while hydroxyurea can generally be continued throughout the perioperative period, close monitoring for wound healing complications and other adverse effects is essential, with a low threshold for discontinuation if problems arise.