The role of vitamin B₆ in the prevention of haematological toxic effects of linezolid in patients with cancer

Background: Linezolid is the first approved synthetic oxazolidinone with activity against multidrug-resistant Gram-positive pathogens. However, haematological toxic effects of linezolid frequently limit its prolonged use, especially in patients with poor marrow reserves such as those with cancer receiving chemotherapy. Previous authors have reported that administration of vitamin B₆ with linezolid reversed pancytopenia in two patients. Methods: This is an open-label study of 31 patients with cancer who received linezolid at 600 mg twice daily and vitamin B₆ at 50 mg/day for at least 2 weeks mean therapy duration and they were matched to 62 control patients who received linezolid without vitamin B₆ to determine whether the concomitant use of vitamin B₆ attenuates the haematological toxicity of linezolid in patients with cancer. Results: Patients were matched according to age, underlying disease, duration of therapy, creatinine level and use of chemotherapy. We found no significant differences in the rate of haematological toxic effects between the two patient groups. The rate of thrombocytopenia was 13% in the vitamin B₆ group and 15% in the control group (P = 0.82). Also, the rate of leucopenia was 7% versus 5%, respectively (P = 0.75). None of the patients in the vitamin B⁶ group had anaemia compared with 5% in the control group. Conclusions: Vitamin B₆ given at 50 mg/day may have an impact on anaemia but did not prevent linezolid-induced thrombocytopenia or leucopenia in cancer patients.