Website intended for a NZ health professional readership
Metformin is generally described as safe, effective and cheap, but one notable harm associated with its use is vitamin B12 deficiency
1. Harrington DJ. Laboratory assessment of vitamin B12 status. J Clin Pathol 2017;70(2):168–73.
2. Hunt A, Harrington D, Robinson S. Vitamin B12 deficiency. BMJ 2014;349:g5226.
3. Haeusler S, Parry-Strong A, Krebs JD. The prevalence of low vitamin B12 status in people with type 2 diabetes receiving metformin therapy in New Zealand–a clinical audit. N Z Med J 2014;127(1404):8–16.
4. Wile DJ, Toth C. Association of metformin, elevated homocysteine, and methylmalonic acid levels and clinically worsened diabetic peripheral neuropathy. Diabetes Care 2010;33(1):156–61.
5. Out M, Kooy A, Lehert P, et al. Long-term treatment with metformin in type 2 diabetes and methylmalonic acid: Post hoc analysis of a randomized controlled 4.3year trial. J Diabetes Complications 2018;32(2):171–78.
6. Wang H, Li L, Qin LL, et al. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Cochrane Database Syst Rev 2018;3(3):CD004655.
7. Sanz-Cuesta T, Escortell-Mayor E, Cura-Gonzalez I, et al. Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care: a pragmatic, randomised, non-inferiority clinical trial (OB12). BMJ Open 2020;10(8):e033687.
8. Devalia V, Hamilton MS, Molloy AM. Guidelines for the diagnosis and treatment of cobalamin and folate disorders. Br J Haematol 2014;166(4):496–513.
9. Obeid R, Fedosov SN, Nexo E. Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention or treatment of cobalamin deficiency. Mol Nutr Food Res 2015;59(7):1364–72.
Pharmacist prescribers Linda Bryant and Leanne Te Karu discuss positive polypharmacy for heart failure. Current evidence shows the intensive implementation of four medications offers the greatest benefit to most patients with heart failure, with significant reductions in cardiovascular mortality, heart failure hospitalisations and all-cause mortality
