What SGLT2 inhibitors do
SGLT2 = Sodium-Glucose Co-transporter 2 — a protein in the kidney tubule that normally reabsorbs glucose from urine back into the bloodstream.
SGLT2 inhibitors BLOCK this protein, so:
- Glucose is lost in urine (~70 g/day = 280 kcal)
- Sodium and water are also lost (mild diuretic effect)
- BP falls by 3–5 mmHg
- Weight falls by 2–3 kg over months
- Pressure inside the kidney's filters (glomeruli) reduces — this is what protects them long-term
Benefits proven in major trials (DAPA-CKD, EMPA-KIDNEY, CREDENCE):
- ~40% reduction in CKD progression
- ~30% reduction in heart failure deaths
- ~20% reduction in overall mortality
- Effective whether you have diabetes or not
- Effective at all CKD stages above eGFR 20
Who should take one?
NICE RECOMMENDS dapagliflozin or empagliflozin for adults with CKD if you have:
- Type 2 diabetes (any CKD stage above eGFR 25), OR
- Urine ACR ≥ 22.6 mg/mmol (significant proteinuria), OR
- Heart failure with reduced or preserved ejection fraction
ALSO CONSIDERED in:
- ADPKD (autosomal dominant polycystic kidney disease) — some evidence
- Post-transplant — emerging evidence
- Type 1 diabetes — specialist supervision only (DKA risk)
NOT USUALLY USED in:
- eGFR < 20 (limited evidence; specialist decision)
- Frequent UTIs or genital thrush
- Active foot ulcer (canagliflozin only — slight amputation risk)
- Pregnancy and breastfeeding
Kidney Vitality is a daily multivitamin developed by a UK Consultant Nephrologist using renal nutrition principles. It contains no added potassium, magnesium, phosphorus or iron, and no herbal blends. See the formulation.
Starting an SGLT2 inhibitor
What To Expect
- Usual dose: dapagliflozin 10 mg once daily or empagliflozin 10 mg once daily
- First 2 weeks: eGFR may dip by 5–10 ml/min (this is normal and protective long-term)
- Don't be alarmed — your team expects this 'dip'
- Drink normally — neither restrict nor over-drink
- Continue ACE inhibitor / ARB / blood pressure meds as prescribed
- Your renal team will check bloods at 2–4 weeks then 3 months
If You Have Diabetes
- Insulin and sulfonylurea doses may need reducing (hypo risk)
- Discuss with your diabetes team
- HbA1c may fall by 5–10 mmol/mol
Side effects and how to manage them
COMMON (1 in 10):
- Genital thrush (yeast infection) — easily treated with clotrimazole cream/pessary. Good genital hygiene helps. Continue the medication.
- Mild dehydration — drink normally to thirst; don't restrict fluids unless told
- Slightly more frequent urination
LESS COMMON (1 in 100):
- UTIs — treat as normal; recurrent UTIs may mean stopping
- Postural dizziness — especially in elderly on diuretics; sit before standing
Rare But Serious
- Diabetic ketoacidosis (DKA) — mainly type 1 diabetes; can occur with normal blood sugars ('euglycaemic DKA'). Warning signs: nausea, vomiting, abdominal pain, fast breathing. Stop and seek urgent help.
- Fournier's gangrene (severe genital infection) — extremely rare. Severe pain, swelling, fever — A&E immediately.
- Lower limb amputation — only seen with canagliflozin in CANVAS trial. Avoid if active foot ulcer.
Sick-day rules — important
TEMPORARILY STOP your SGLT2 inhibitor if you have:
- Vomiting and/or diarrhoea > 24 hours
- Severe infection with fever and poor fluid intake
- Surgery (stop 48 hours before; restart when eating again)
- Acute hospital admission
- Acute kidney injury (rising creatinine)
This prevents:
- Dehydration
- Euglycaemic DKA
- Worsening AKI
RESTART when:
- Eating and drinking normally
- 24–48 hours after illness resolves
- Confirmed by your GP or renal team
Also pause your ACE inhibitor / ARB and diuretics during severe illness (this is the standard 'sick-day medicines' list — your renal team will give you a card). Don't stop them long-term without advice.
