Colchicine Neuropathy or Vitamin B₁₂ Deficiency Neuropathy?

To the Editor: Kuncl et al. (June 18 issue)¹ argued that colchicine myopathy may be a common disorder among patients who take customary doses of the drug (1.2 mg per day) for gout, and that the disorder is nearly always associated with a mild axonal polyneuropathy. They analyzed 12 cases to determine the primary risk factors but neglected to consider vitamin B₁₂ deficiency as a possible cause of the associated neuropathies. Colchicine can induce the malabsorption of vitamin B₁₂ by means of a dose-related, reversible reduction in the quantity of intrinsic-factor–vitamin B₁₂ receptors in the intestinal mucosa….