💊 SGLT2 Inhibitors

SGLT2 inhibitors (sodium-glucose co-transporter 2 inhibitors) are a class of oral antidiabetic drugs used primarily in the management of type 2 diabetes mellitus.

They work by inhibiting the SGLT2 protein in the renal proximal tubules, which is responsible for reabsorbing approximately 90% of filtered glucose. This inhibition leads to increased urinary glucose excretion (glucosuria), thereby lowering blood glucose levels independently of insulin.

Primarily indicated for the treatment of type 2 diabetes mellitus, often as an add-on therapy or in patients unable to use metformin. They are also increasingly used for their cardiovascular and renal benefits, including in patients with heart failure with reduced ejection fraction and chronic kidney disease, even without diabetes.

Severe renal impairment (eGFR below a certain threshold, which varies by drug) is a key contraindication due to reduced efficacy and potential for adverse effects. Hypersensitivity to the active substance or excipients is also an absolute contraindication. Not recommended for use in type 1 diabetes due to the increased risk of euglycaemic diabetic ketoacidosis.

Common adverse effects include genitourinary infections (e.g., thrush, UTIs) due to glucosuria, and polyuria leading to dehydration and hypotension. Rare but serious adverse effects include euglycaemic diabetic ketoacidosis (DKA), Fournier's gangrene, and lower limb amputation (canagliflozin).

Renal function (eGFR) should be assessed before initiating treatment and periodically thereafter, especially in elderly patients or those with pre-existing renal impairment. Blood glucose levels should be monitored regularly. Patients should be advised to monitor for symptoms of dehydration and genitourinary infections.

Always check renal function before prescribing and ensure it's within acceptable limits. Counsel patients on the importance of hydration and hygiene to prevent genitourinary infections. Warn about symptoms of DKA (even with normal glucose) and the need to seek urgent medical attention. Be aware of potential interactions with diuretics, increasing dehydration risk.

High-yield for their 'beyond glycaemic control' benefits in heart failure and CKD. Remember the risk of euglycaemic DKA, particularly in type 1 diabetes (where they are contraindicated) or during illness/surgery. They are increasingly first-line in type 2 diabetes with established cardiovascular disease or CKD. Know the common side effects like UTIs and candidiasis.

SBAs often focus on the cardiovascular and renal protective benefits, asking which drug class offers these. Questions may also test recognition of DKA in the context of normal glucose levels (euglycaemic DKA) or the management of genitourinary infections. Expect scenarios involving patients with heart failure or CKD benefiting from these drugs.