Januvia (Sitagliptin) Dosing in Renal Impairment
For patients with impaired renal function, Januvia requires dose reduction based on eGFR: 100 mg daily if eGFR >50 mL/min/1.73 m², 50 mg daily if eGFR 30-50 mL/min/1.73 m², and 25 mg daily if eGFR <30 mL/min/1.73 m² including patients on dialysis. 1
Dosing Algorithm by Renal Function
The dosing adjustments are straightforward and based solely on kidney function:
- eGFR >50 mL/min/1.73 m²: Standard dose of 100 mg once daily 1
- eGFR 30-50 mL/min/1.73 m²: Reduced dose of 50 mg once daily 1
- eGFR <30 mL/min/1.73 m²: Further reduced dose of 25 mg once daily 1
- End-stage renal disease (ESRD) on dialysis: 25 mg once daily, administered without regard to timing of dialysis 1, 2
Clinical Evidence Supporting Safety in Renal Impairment
The reduced doses in renal impairment are designed to achieve plasma concentrations similar to those in patients with normal renal function receiving 100 mg daily. 2 This dosing strategy has been validated in clinical trials showing that sitagliptin is generally well tolerated and provides effective glycemic control even in patients with moderate to severe renal insufficiency, including those with ESRD on dialysis. 2
In a 54-week randomized trial of patients with renal insufficiency, sitagliptin reduced HbA1c by 0.6% at 12 weeks and 0.7% at 54 weeks, with significantly lower rates of hypoglycemia (4.6%) compared to glipizide (23.1%). 2
Key Advantages in Renal Disease
Unlike other DPP-4 inhibitors that require dose adjustment at different thresholds, sitagliptin has clear, evidence-based dosing recommendations across all stages of CKD. 1 The medication is primarily renally excreted, which necessitates these adjustments but also makes dosing predictable. 3
Important Clinical Considerations
- No dose adjustment needed for linagliptin (an alternative DPP-4 inhibitor) as it is hepatically metabolized, which may be preferred if frequent eGFR monitoring is challenging. 1
- Hypoglycemia risk is low with sitagliptin monotherapy or when combined with metformin, but increases when combined with sulfonylureas or insulin—consider reducing doses of these agents. 2
- Monitor renal function at baseline and periodically, as diabetes itself can affect kidney function over time. 4
- The standard 100 mg dose should not be used in patients with eGFR <50 mL/min/1.73 m² to avoid drug accumulation. 1
Medication Appearance
Januvia tablets are available in three strengths corresponding to the renal dosing tiers: 25 mg (pink), 50 mg (light beige), and 100 mg (beige) round film-coated tablets. 3 Each tablet is marked with "Merck" on one side and the strength on the other, making identification straightforward for patients and providers.