Preventing Metformin Side Effects
Depression is a risk factor for type 2 diabetes, and the drug metformin is a common treatment for diabetes. In a 2016 article in the Journal of Clinical Psychiatry, researcher Chittaranjan Andrade suggests ways of minimizing side effects from metformin.
Gastrointestinal side effects such as nausea, vomiting, abdominal discomfort, flatulence, and diarrhea are common on metformin. In the article, Andrade writes, “These are less likely to occur with gradual dose uptitration, administration of the drug with meals, and use of a time-release formulation.”
Lactic acidosis, a buildup of lactate in the body that can result in muscle pain, burning, and other symptoms, is a rare side effect of metformin. Avoiding prescribing metformin to people with impaired kidney, liver, or cardiac functioning and other risk factors can prevent lactic acidosis.
Vitamin B12 absorption can also be affected by long-term metformin use. Andrade suggests that rather than waiting for a vitamin deficiency to be identified, a proactive approach should be taken. Long-term metformin users could be given an annual intramuscular shot of vitamin B12.
Diabetes Drug Metformin May Impair Cognition, But Vitamin B12 May Help
Metformin, one of the most popular drugs to treat type 2 diabetes, interferes with uptake of vitamin B12, which can in turn lead to some neuronal dysfunction resulting in cognitive dysfunction. Several studies have sought to clarify this link, which may affect up to 30% of patients taking the drug.
Most recently, an Australian analysis of 1354 aging patients found that those with type 2 diabetes performed less well on tests of cognitive abilities, and those diabetic patients with low vitamin B12 levels (below 250 pmol/L) scored lower than those diabetic patients with adequate levels.
Because of the malabsorption problem caused by metformin, patients taking the drug may not be able to get enough B12 from a balanced diet alone and may need supplemental B12. Those who follow a vegetarian diet, have had bowel surgery, have certain complications with the stomach, or who take other medications that depress stomach acid may be at special risk.
Physicians should carefully monitor B12 levels in patients taking metformin, particularly those who have been taking the drug for more than 3 years or those who already suffer from some sort of cognitive impairment.
