Farxiga (Dapagliflozin) and Potassium Levels
Farxiga (dapagliflozin) does not cause hyperkalemia and is actually one of the few heart failure medications that does not affect potassium levels. 1
Mechanism and Potassium Effects
Sodium-glucose co-transporter 2 (SGLT2) inhibitors like dapagliflozin have a unique profile among heart failure and diabetes medications:
- Unlike mineralocorticoid receptor antagonists (MRAs) which are associated with significant hyperkalemia risk, SGLT2 inhibitors do not increase serum potassium 1
- Dapagliflozin is specifically noted to "not affect blood pressure, heart rate, or potassium levels" 1
- Pooled analysis of clinical trials showed no clinically relevant mean changes from baseline in serum potassium with dapagliflozin 10 mg compared to placebo 2
Evidence from Clinical Trials
The evidence consistently demonstrates that dapagliflozin does not increase hyperkalemia risk:
- In the DAPA-HF trial, there was no significant increase in hyperkalemia events with dapagliflozin compared to placebo 1
- The incidence rate ratio for serum potassium ≥5.5 mmol/L for dapagliflozin 10 mg versus placebo was 0.90 (95% CI 0.74,1.10), indicating no increased risk 2
- Dapagliflozin may actually facilitate the use of mineralocorticoid receptor antagonists (MRAs), as patients on SGLT2 inhibitors and taking MRAs are less likely to experience severe hyperkalemia 1
Special Populations
The safety profile regarding potassium remains consistent across different patient populations:
No increased risk of hyperkalemia was observed in patients:
- Receiving ARBs/ACE inhibitors
- Using potassium-sparing diuretics
- With moderate renal impairment 2
In the DAPA-CKD trial, the effect of dapagliflozin on hyperkalemia (HR 0.87,95% CI 0.70-1.09) was consistent regardless of whether patients were also taking MRAs 3
Clinical Implications
This favorable potassium profile makes dapagliflozin particularly valuable in heart failure management:
- SGLT2 inhibitors can be safely combined with other heart failure medications that do carry hyperkalemia risk (such as ACE inhibitors, ARBs, and MRAs) 1, 3
- The medication can be initiated during hospitalization for heart failure with minimal concern about electrolyte disturbances 1
- Dapagliflozin may actually help reduce the risk of hyperkalemia when used in combination with MRAs 1
Rare Exception
There is one documented case report of hyperkalemia developing after dapagliflozin administration in a patient with bilateral adrenalectomy and mineralocorticoid deficiency 4. This suggests that in the rare setting of aldosterone deficiency, compensatory RAAS activation may be impaired, potentially leading to hyperkalemia.
Bottom Line
Dapagliflozin does not cause hyperkalemia in the vast majority of patients and may actually facilitate the use of other medications that do carry this risk. This favorable potassium profile is one of several characteristics that make SGLT2 inhibitors uniquely valuable in the treatment of heart failure and diabetes.