From the Guidelines
For safe use of empagliflozin, telmisartan, and spironolactone, specific renal function thresholds must be observed, with empagliflozin not being initiated when eGFR is below 30 mL/min/1.73m² and should be discontinued if eGFR persistently falls below 20 mL/min/1.73m², as supported by the most recent guidelines 1.
Key Considerations for Each Medication
- Empagliflozin: Should not be initiated with eGFR below 30 mL/min/1.73m² and discontinued if eGFR falls below 20 mL/min/1.73m², based on recommendations for SGLT2 inhibitors in patients with type 2 diabetes and diabetic kidney disease 1.
- Telmisartan: Requires caution when eGFR is below 30 mL/min/1.73m², with close monitoring recommended, though no specific dose adjustment is required, considering its effects on potassium levels and renal function 2.
- Spironolactone: Should be avoided when eGFR is below 30 mL/min/1.73m² due to increased risk of hyperkalemia, as mineralocorticoid receptor antagonists can significantly affect potassium levels, especially in compromised renal function 2.
Monitoring and Safety Precautions
Regular monitoring of renal function and electrolytes, particularly potassium, is crucial for patients taking these medications, especially those with borderline kidney function, to prevent adverse effects such as hyperkalemia and further renal function decline 3, 4. The mechanism of empagliflozin, which depends on adequate glomerular filtration for glucose excretion, and the potential of telmisartan and spironolactone to affect potassium levels and renal function, underscore the importance of these monitoring and safety precautions.
Clinical Decision Making
Clinical decisions regarding the initiation, continuation, or discontinuation of these medications should be based on the most recent and highest quality evidence, prioritizing patient safety and the prevention of morbidity, mortality, and reduction in quality of life. The guidelines and recommendations from reputable sources such as the American Diabetes Association (ADA) and Kidney Disease: Improving Global Outcomes (KDIGO) should guide clinical practice 3, 4.
From the Research
Renal Function and Medication Tolerance
The lower limit of renal function for tolerating empagliflozin, telmisartan, and spironolactone can be assessed based on the available studies.
- Empagliflozin: + A study 5 found that empagliflozin was well tolerated in subjects with normal renal function and any degree of renal impairment, with no increase in adverse events associated with renal impairment. + Another study 6 showed that empagliflozin had a beneficial effect on key efficacy outcomes and slowed the rate of kidney function decline in patients with and without chronic kidney disease (CKD), and regardless of the severity of kidney impairment at baseline, including patients with eGFR as low as 20 ml/min/1.73 m2.
- Telmisartan: + A study 7 assessed the clinical efficacy and safety of telmisartan in patients with varying severity of CKD and found that telmisartan provided effective and well-tolerated treatment of mild/moderate hypertension in CKD patients, with no worsening of renal function. + The study 7 included patients with creatinine clearance (CrCl) 30 - 74 ml/min/1.73 m2, indicating that telmisartan can be tolerated in patients with mild to moderate renal impairment.
- Spironolactone: + There is limited information available on the specific lower limit of renal function for spironolactone tolerance. + A review 8 discussed the importance of medication safety in kidney disease and highlighted the need for cautious use of certain medications, including spironolactone, in patients with CKD. + However, the review 8 did not provide specific guidance on the lower limit of renal function for spironolactone tolerance.
Key Findings
- Empagliflozin can be tolerated in patients with eGFR as low as 20 ml/min/1.73 m2 6.
- Telmisartan can be tolerated in patients with CrCl 30 - 74 ml/min/1.73 m2 7.
- There is limited information available on the specific lower limit of renal function for spironolactone tolerance.
- Medication safety in kidney disease requires careful consideration of the potential risks and benefits of each medication, as well as regular monitoring of renal function and adjustment of medication dosages as needed 8, 9.