What to do with metformin (Metformin) and diarrhea?

From the Guidelines

If you're experiencing diarrhea from metformin, the most effective approach is to try taking it with meals to reduce gastrointestinal side effects, consider switching to extended-release metformin, and start with a lower dose (like 500mg daily) that can be gradually increased as tolerated, as recommended by the latest guidelines 1. When managing metformin-induced diarrhea, it's essential to weigh the benefits of continued metformin use against the potential drawbacks of gastrointestinal side effects. The principal side effects of metformin, including bloating, abdominal discomfort, and diarrhea, can be mitigated by gradual dose titration and/or using extended-release formulation 1. Key considerations for managing diarrhea from metformin include:

• Taking metformin with meals to reduce gastrointestinal side effects
• Switching to extended-release metformin, which often causes less diarrhea than immediate-release formulations
• Starting with a lower dose (like 500mg daily) and gradually increasing it as tolerated
• Temporary dose reduction to help the body adjust
• Staying well-hydrated and avoiding foods that might worsen diarrhea
• Contacting the healthcare provider if diarrhea persists beyond 2 weeks or is severe, as they might need to adjust the medication regimen 1. It's crucial not to stop taking metformin without medical advice, as these side effects typically improve over time as the body adjusts to the medication, usually within 1-2 weeks 1. Metformin's mechanism of altering intestinal glucose metabolism and potentially changing gut microbiota contributes to both its beneficial effects on blood glucose control and its gastrointestinal side effects 1.

From the FDA Drug Label

Common side effects of metformin hydrochloride tablets include diarrhea, nausea, and upset stomach. These side effects generally go away after you take the medicine for a while. Taking your medicine with meals can help reduce these side effects. Tell your doctor if the side effects bother you a lot, last for more than a few weeks, come back after they've gone away, or start later in therapy. You may need a lower dose or need to stop taking the medicine for a short period or for good.

If you experience diarrhea while taking metformin, it is a common side effect that may go away after a while. To help reduce this side effect, you can try taking your medicine with meals. If the diarrhea bothers you a lot, lasts for more than a few weeks, comes back after it's gone away, or starts later in therapy, you should tell your doctor. You may need a lower dose or need to stop taking the medicine for a short period or for good 2.

From the Research

Managing Metformin-Induced Diarrhea

• Diarrhea is a common side effect of metformin, affecting a significant proportion of patients taking this medication for type 2 diabetes 3, 4.
• Studies have shown that extended-release metformin may be better tolerated than immediate-release metformin, with fewer gastrointestinal side effects, including diarrhea 3, 5, 6.
• Switching from immediate-release metformin to extended-release metformin may help reduce the frequency of diarrhea and other gastrointestinal side effects 3, 4.
• Starting with a low dose and gradually increasing it may also help minimize gastrointestinal side effects, including diarrhea 4.
• Other strategies to overcome metformin-induced diarrhea include using delayed-release metformin, gut microbiome modulators, and alternative pharmacological therapies if metformin cannot be tolerated 4.

Comparison of Metformin Formulations

• Metformin extended release (XR) has been shown to be as effective as metformin immediate release (IR) in controlling blood sugar levels, with fewer side effects, including diarrhea 5, 7.
• A study comparing metformin XR and IR found that metformin XR was associated with a lower incidence of diarrhea and other gastrointestinal side effects, even at equivalent doses 5.
• Another study found that metformin XR was more effective than metformin IR in improving glycemic control, lipid profile, and levels of certain adipocytokines, with fewer gastrointestinal side effects 7.

Clinical Implications

• Healthcare providers should consider switching patients experiencing diarrhea and other gastrointestinal side effects from immediate-release metformin to extended-release metformin 3, 4.
• Patients should be started on a low dose of metformin and gradually increased to minimize gastrointestinal side effects, including diarrhea 4.
• Alternative formulations, such as delayed-release metformin, and other pharmacological therapies should be considered if metformin cannot be tolerated due to gastrointestinal side effects 4.