What are SGLT2 Medications?
SGLT2 inhibitors (sodium-glucose cotransporter-2 inhibitors), also known as gliflozins, are a class of medications that work by blocking glucose reabsorption in the kidneys, causing excess glucose to be eliminated in the urine. 1, 2
Mechanism of Action
SGLT2 inhibitors work independently of insulin by targeting the SGLT2 cotransporter proteins located in the proximal tubules of the kidney 2, 3. These transporters are normally responsible for reabsorbing approximately 90% of filtered glucose back into the bloodstream 4. By inhibiting this reabsorption, SGLT2 inhibitors:
- Promote urinary glucose excretion (glucosuria)
- Lower blood glucose levels without requiring insulin
- Reduce sodium reabsorption alongside glucose 3
The amount of glucose excreted depends on both the degree of hyperglycemia and kidney function (glomerular filtration rate) 4.
Available Medications
The SGLT2 inhibitor class includes several agents 1, 3:
- Canagliflozin
- Dapagliflozin
- Empagliflozin
- Ertugliflozin
- Ipragliflozin
- Sotagliflozin (dual SGLT1/2 inhibitor)
Clinical Benefits Beyond Glucose Control
SGLT2 inhibitors have demonstrated profound cardiovascular and kidney protective effects that extend far beyond their glucose-lowering properties 1, 2. High-certainty evidence from 13 randomized trials involving 29,614 participants shows these medications:
Mortality Benefits
- Reduce all-cause mortality (48 fewer deaths per 1000 patients in very high-risk groups) 1
- Decrease cardiovascular mortality 1
Cardiovascular Benefits
- Reduce heart failure hospitalizations by approximately 30% 5
- Decrease non-fatal myocardial infarction 1
- Reduce non-fatal stroke 1
Kidney Protection
- Slow progression of chronic kidney disease 1
- Reduce kidney failure (58 fewer cases per 1000 in very high-risk patients) 1
Metabolic Effects
- Promote weight loss through negative energy balance 2, 6
- Lower blood pressure 4
- Reduce serum uric acid 2
- Induce favorable metabolic adaptations including ketone production 2
Who Should Receive SGLT2 Inhibitors
Current 2024 BMJ guidelines provide strong recommendations for SGLT2 inhibitor use in adults with chronic kidney disease, regardless of diabetes status 1:
- Strong recommendation (high/very high risk CKD): Adults at high or very high risk of CKD progression should receive SGLT2 inhibitors 1
- Weak recommendation (low/moderate risk CKD): Adults at low or moderate risk of CKD progression should be offered SGLT2 inhibitors 1
These recommendations apply to all adults with CKD, whether or not they have type 2 diabetes 1.
Safety Profile and Adverse Effects
SGLT2 inhibitors are generally well-tolerated, but clinicians must be aware of specific risks 2, 3, 7:
Common Adverse Effects
- Genitourinary infections: Most frequent adverse event, particularly genital mycotic infections in women 4, 8
- Urinary tract infections: Less common than genital infections and generally benign 4
- Urinary frequency and dehydration: Due to osmotic diuresis 7, 8
Serious but Rare Complications
- Euglycemic diabetic ketoacidosis (euDKA): A deceptive metabolic emergency with severe acidosis but normal glucose levels 2, 8
- Lower-extremity amputations: Specifically associated with canagliflozin 7
- Bone fractures: Also linked to canagliflozin 7
Important Prescribing Considerations
- Efficacy declines with worsening renal function 4
- Caution in elderly patients due to higher risk of dehydration and orthostatic hypotension 4
- Safety data limited for GFR <20 mL/min/1.73 m² 1
- Perioperative management critical: Should be held before surgery due to euDKA risk 8
Clinical Positioning
SGLT2 inhibitors have evolved from glucose-lowering agents to foundational organ-protective therapies 5, 6. Current guidelines position them alongside RAAS inhibitors, β-blockers, and mineralocorticoid receptor antagonists as core therapy for heart failure and chronic kidney disease 5. Their unique insulin-independent mechanism makes them valuable at any stage of type 2 diabetes 4, with the critical advantage of minimal hypoglycemia risk compared to sulfonylureas 4.