Hemolysis attributed to high dose vitamin C: Two case reports

Area of Science:

• Oncology
• Pharmacology
• Hematology

Background:

• High-dose vitamin C treatment (HVCT) is explored as an adjunct cancer therapy, often considered safe.
• However, severe adverse effects, including potentially fatal hemolysis, are increasingly recognized.
• The exact mechanisms and risk factors for HVCT-induced hemolysis, particularly in glucose-6-phosphate dehydrogenase (G6PD) deficiency, require further elucidation.

Observation:

• Two colorectal cancer patients developed severe hemolytic anemia following HVCT (1 g/kg).
• Hemoglobin levels dropped below 50 g/L, exceeding previously reported severities.
• Co-existing conditions like chronic hepatitis B and bone marrow suppression may exacerbate hemolysis.

Findings:

• All reviewed patients with G6PD deficiency experienced hemolysis after HVCT.
• The presented cases, despite extreme hemolysis, showed a favorable prognosis with blood replacement therapy.
• This suggests potential therapeutic strategies for managing drug-induced hemolysis.

Implications:

• G6PD deficiency must be considered a strict contraindication for HVCT.
• Patients with pre-existing anemia, bone marrow suppression, or abnormal liver/kidney function should avoid HVCT.
• Prompt blood purification and steroid therapy are crucial for mitigating severe outcomes like acute kidney injury or death.