From the Guidelines
Sitagliptin and metformin should be used with caution in patients with an eGFR of 33 ml/min/1.73m² and uncontrolled diabetes, with careful monitoring and dose adjustments as necessary. Given the patient's eGFR of 33 ml/min/1.73m², metformin can be used but with a reduced dose, as it is contraindicated when eGFR falls below 30 ml/min/1.73m² due to increased risk of lactic acidosis 1. The recommended dose reduction for metformin is to 1000 mg daily, and for sitagliptin, the dose should be adjusted to 50 mg daily with an eGFR between 30-45 ml/min/1.73m² 1. Some key points to consider when using these medications in patients with impaired kidney function include:
- Regular monitoring of kidney function (every 3-6 months) 1
- Monitoring of blood glucose levels and A1C
- Consideration of alternative medications like certain SGLT2 inhibitors (if eGFR >30) or GLP-1 receptor agonists, which may be safer options with additional kidney protection benefits 1
- Insulin therapy as a potential safest and most effective approach for uncontrolled diabetes with significant kidney impairment 1 It is essential to consult with both an endocrinologist and nephrologist to develop an appropriate treatment plan given the specific situation, taking into account the patient's kidney function, blood glucose levels, and other health considerations 1.
From the Research
Safety of Sitagliptin and Metformin in Uncontrolled Diabetes with 33 eGFR
- The safety of sitagliptin and metformin in patients with uncontrolled diabetes and an estimated glomerular filtration rate (eGFR) of 33 has been evaluated in several studies 2, 3.
- A study published in 2011 found that metformin and sitagliptin are frequently used at inappropriate doses in patients with renal impairment, including those with an eGFR of 30-59 mL/min/1.73 m² 2.
- Another study published in 2017 reviewed the use of sitagliptin in type 2 diabetes and found that it is generally well tolerated, with most adverse events being of mild to moderate intensity, and is not associated with an increased risk of cardiovascular disease or hypoglycemia 3.
- However, there is limited information available on the specific use of sitagliptin and metformin in patients with an eGFR of 33, and further studies are needed to fully evaluate their safety and efficacy in this population.
Dose Adjustment and Renal Impairment
- The study published in 2011 found that only 15.1% of patients with orders for sitagliptin and 0.1% of patients with orders for metformin received doses of the drug appropriate for their degree of renal impairment 2.
- This suggests that dose adjustment is important in patients with renal impairment, including those with an eGFR of 33, to minimize the risk of adverse events and optimize the efficacy of sitagliptin and metformin.
- The study published in 2017 recommended that the dose of sitagliptin be adjusted based on the patient's renal function, with a reduced dose recommended for patients with moderate or severe renal impairment 3.
Combination Therapy and Uncontrolled Diabetes
- Several studies have evaluated the use of combination therapy, including metformin and sitagliptin, in patients with uncontrolled type 2 diabetes 4, 5.
- A study published in 2020 found that the combination of premixed insulin, metformin, and a glucagon-like peptide 1 receptor agonist improved glycemic control in patients with historically uncontrolled type 2 diabetes 4.
- Another study published in 2021 found that the addition of dapagliflozin to dual therapy with metformin and saxagliptin improved glycemic control and reduced body weight and blood pressure in patients with uncontrolled type 2 diabetes 5.
- These studies suggest that combination therapy, including metformin and sitagliptin, may be effective in improving glycemic control in patients with uncontrolled type 2 diabetes, including those with an eGFR of 33.