Precaution to patient who are hypersensitivity to Thiamine, Cyanocobalamin, and Pyridoxine. Long term administration is associated with the development of severe peripheral neuropathies. This may occur with doses in excess of about 2 grams daily.
Cyanocobalamin should not be used in megaloblastic anemia of pregnancy, administration of doses greater than 10 microgams daily may produce hematological response in patients with folate deficiency.