From the Guidelines
To improve diarrhea from metformin, start with a lower dose and gradually increase it as tolerated, and consider taking the medication with meals or switching to an extended-release formulation, as recommended by the most recent guidelines 1. When initiating metformin therapy, it is essential to begin with a low dose, such as 500 mg once daily, and gradually increase it as tolerated to minimize gastrointestinal side effects, including diarrhea.
- Taking metformin with meals can help reduce gastrointestinal side effects, as food can slow down the absorption of the medication and decrease the risk of diarrhea.
- Switching to an extended-release formulation of metformin, such as Glucophage XR, may also help alleviate diarrhea, as it is designed to release the medication more slowly and reduce peak plasma concentrations.
- Temporary over-the-counter medications like loperamide (Imodium) at 2 mg after each loose stool (not exceeding 8 mg per day) may help manage symptoms while the body adjusts to the medication.
- Staying well-hydrated by drinking plenty of water and avoiding foods that might worsen diarrhea, such as spicy foods, dairy products, and caffeine, can also help alleviate symptoms.
- Metformin-related diarrhea typically improves within 2-3 weeks as the body adapts to the medication, but if severe diarrhea persists beyond a few weeks despite these measures, it is crucial to contact the healthcare provider, as they may need to adjust the dosage or consider alternative diabetes medications, as suggested by recent studies 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. To improve diarrhea from metformin, consider the following:
- Take the medicine with meals to help reduce diarrhea and other gastrointestinal side effects.
- 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, tell your doctor, as you may need a lower dose or need to stop taking the medicine for a short period or for good 2.
From the Research
Improving Diarrhea from Metformin
To improve diarrhea from metformin, several strategies can be considered:
- Starting at a low dose and titrating slowly may help prevent some gastrointestinal adverse events associated with metformin 3
- Using extended-release metformin may also help reduce gastrointestinal symptoms 3, 4
- Probiotics have been shown to reduce the incidence of gastrointestinal adverse events, including diarrhea, in patients with type 2 diabetes and metformin intolerance 5, 6, 7
- A multi-strain probiotic may be more effective in reducing gastrointestinal symptoms than a single-strain probiotic 5, 6
- The specific probiotic strain Bifidobacterium bifidum G9-1 has been shown to improve gastrointestinal symptoms, including diarrhea, in patients with type 2 diabetes mellitus treated with metformin 7
Mechanisms and Factors
The underlying mechanisms of metformin-associated gastrointestinal intolerance are poorly understood, but may involve changes in the gut microbiota 3
- Genotype variability and associated factors, such as comorbidities, co-medications, and bariatric surgery, may also affect metformin gastrointestinal intolerance 3
- The use of probiotics may help modulate the gut microbiota and reduce gastrointestinal symptoms 5, 6, 7
Clinical Implications
Gastrointestinal symptoms, including diarrhea, are common in patients with type 2 diabetes taking metformin 3, 4