From the Guidelines
The concomitant use of colchicine and metformin is not absolutely contraindicated, but caution is advised due to the potential increased risk of lactic acidosis.
Key Considerations
- Colchicine, particularly at high doses (e.g., 1.2 mg orally per day) or prolonged durations (e.g., greater than 3 months), may increase the risk of metformin-associated lactic acidosis 1.
- Patients taking metformin (e.g., 500-2000 mg orally per day) and colchicine should be closely monitored for signs of lactic acidosis, such as muscle cramps, fatigue, and dyspnea, and the benefits of concurrent use should be carefully weighed against the potential risks 1.
Monitoring and Precautions
- eGFR should be monitored every 3 to 6 months in those at risk for decline in kidney function, as metformin is contraindicated in those with advanced renal insufficiency 1.
- Metformin may be used safely in individuals with an estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m², while lower doses may be used in those with an eGFR 30–45 mL/min/1.73 m² 1.
- The daily dose of metformin should be slowly increased to minimize gastrointestinal side effects, and reduction or elimination of metformin may be necessary for those experiencing persistent gastrointestinal side effects 1.
From the Research
Metformin and Lactic Acidosis
- Metformin is an oral anti-hyperglycemic agent used in the treatment of type 2 diabetes mellitus 2, 3, 4, 5.
- The risk of lactic acidosis with metformin use has been assessed in several studies, with no evidence of an increased risk of lactic acidosis or increased levels of lactate compared to other anti-hyperglycemic treatments 2, 3, 4, 5.
- However, metformin is considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age 2, 3, 4, 5.
Colchicine and Metformin Interaction
- There is no direct evidence in the provided studies regarding the interaction between colchicine and metformin.
- However, it is known that colchicine is a medication used to treat gout and can have potential interactions with other medications, including those that affect renal function 6.
- Metformin is primarily excreted by the kidneys, and any medication that affects renal function may potentially interact with metformin.
Contraindications and Precautions
- Metformin is contraindicated in patients with severe renal impairment, and caution is advised when using metformin in patients with mild to moderate renal impairment 2, 3, 4, 5.
- Patients with risk factors for acute kidney injury, such as age over 80, use of ACE-inhibitors, angiotensin receptor blockers, and diuretics, should be closely monitored when using metformin 6.
- There is no specific information available on the contraindication of colchicine and metformin together, and it is recommended to consult the prescribing information for both medications and consult with a healthcare professional for personalized advice.