Understanding the potential adverse effects of using metformin
In a move aimed at ensuring patient safety, the Food and Drug Administration (FDA) has issued updated guidelines for metformin extended-release tablets. These changes come in response to the detection of nitrosamine impurities, which led to recalls in previous years.
The FDA's latest guidance, titled "Control of Nitrosamine Impurities in Human Drugs," was finalized in September 2024 (Revision 2). This guidance applies specifically to metformin extended-release tablets and sets out new acceptable intake limits and control measures for nitrosamines.
Manufacturers of metformin extended-release tablets must now either reformulate their products or add testing specifications to control nitrosamine levels within these new limits. The effective dates for these guidelines are August 7, 2023, for the Recommended Acceptable Intake Limits and September 5, 2024, for the Control of Nitrosamine Impurities.
Initially, pharmaceutical applicants were required to submit confirmatory testing and implement mitigation strategies for nitrosamine impurities by August 1, 2025. However, the FDA has granted additional time for full compliance, and progress updates are now required if applicants cannot meet this deadline.
Despite these updates, metformin extended-release products such as Glumetza and generic versions continue to be included in pharmacy benefit programs, indicating their continued availability under updated regulatory standards.
While these changes are being implemented, patients should continue to take metformin as prescribed. However, they may notice changes in product formulation or labeling reflecting these safety updates.
In addition to these FDA guidelines, it's important to be aware of other factors that can impact metformin use. For instance, people taking metformin may be at a higher risk of developing a vitamin B-12 deficiency, particularly if they have low vitamin B-12 levels at the start of treatment, low calcium levels in their diet, or low absorption of calcium.
Symptoms of vitamin B-12 deficiency can include changes in skin colour, inflammation of the tongue, decreased reflexes, irritability, decreased sense of smell, nerve damage, difficulty walking, dementia-like symptoms, and an increased risk of anaemia, as well as certain neurological and psychological symptoms.
In such cases, vitamin B-12 and iron supplements may help counteract these deficiencies and anaemia. If issues arise that could be side effects of metformin, it's essential to talk to a doctor about adjusting the dosage or suggesting an alternate medication.
One study suggests that people may experience less diarrhea when they switch from immediate-release to extended-release tablets.
Metformin is a medication used to control blood sugar levels in people with type 2 diabetes. It can be prescribed as a single drug or in combination with other antidiabetic medications.
However, metformin is not suitable for everyone. It's not recommended for people with severe kidney or liver failure, severe infection, heart failure, severe circulatory problems, severe breathing difficulties, alcohol addiction, or an allergy to metformin.
People taking metformin will receive yearly blood tests to monitor for anaemia. Doctors will also check for vitamin B-12 deficiency every 2-3 years.
It's also worth noting that certain drugs, such as diuretics, corticosteroids, thyroid medications, estrogen and combined oral contraceptives, phenytoin, calcium channel blockers, cimetidine, ranolazine, vandetanib, dolutegravir, and carbonic anhydrase inhibitors (CAIs such as topiramate or acetazolamide), may reduce the kidneys' ability to remove metformin from the blood and increase the risk of lactic acidosis.
People who are about to undergo an X-ray, MRI, or CT scan should tell their radiologist if they are taking metformin, as iodinated contrast agents increase the risk of lactic acidosis. Similarly, people taking metformin should avoid consuming excessive amounts of alcohol.
In conclusion, the FDA's updated guidelines for metformin extended-release tablets aim to ensure the safety of this important medication for managing type 2 diabetes. Patients should continue to take metformin as prescribed but may expect changes in product formulation or labeling reflecting these safety updates. If any issues arise, it's crucial to consult a healthcare professional.
- In the realm of health-and-wellness, it's essential for patients to be aware of the new acceptable intake limits and control measures for nitrosamines in metformin extended-release tablets, as stipulated by the FDA's updated guidelines, titled "Control of Nitrosamine Impurities in Human Drugs."
- Beyond nitrosamine impurities, people taking metformin may be at risk of developing a vitamin B-12 deficiency, which can present with symptoms such as changes in skin color, inflammation of the tongue, decreased reflexes, irritability, decreased sense of smell, nerve damage, difficulty walking, dementia-like symptoms, an increased risk of anaemia, and certain neurological and psychological symptoms.
- Therapies and treatments, such as vitamin B-12 and iron supplements, may help counteract these deficiencies and anaemia. If issues arise that could be side effects of metformin, it's essential to talk to a doctor about adjusting the dosage or suggesting an alternate medication.
- In the realm of fitness-and-exercise and mental-health, one study suggests that people may experience less diarrhea when they switch from immediate-release to extended-release tablets of metformin, potentially improving their overall fitness and well-being.
