Empagliflozin: diabetes, heart failure and kidney uses

Empagliflozin is a sodium-glucose co-transporter 2 (SGLT2) inhibitor. The NHS lists three uses: type 2 diabetes, heart failure and chronic kidney disease. The emc information explains that the drug blocks the kidney protein that normally reclaims glucose from urine, so more glucose is passed in the urine, blood sugar falls, and there is a mild water-losing effect and a small drop in blood pressure.

For heart failure and kidney disease, it is prescribed for those conditions in their own right, so people without diabetes can take it. The reasons for prescribing it are individual and come from a specialist or GP.

It is a once-daily tablet. The SmPC states 10 mg once daily for each of the three uses, with the option of increasing to 25 mg for diabetes where kidney function allows. Glucose-lowering effect is reduced when kidney function is lower, and the SmPC does not recommend starting it below a stated kidney threshold. Kidney function is checked before starting and at least yearly.

The NHS lists thrush, urinary discomfort, passing more urine, and mild skin rash or itching. For thrush, the pharmacist can recommend an antifungal; see a doctor if it persists beyond a week or keeps returning. For urinary discomfort, rest, fluids and paracetamol help, and a doctor should be contacted if it lasts beyond two to three days. More frequent urination calls for drinking water or sugar-free drinks to prevent dehydration.

Low blood sugar mainly arises when empagliflozin is combined with insulin or a sulfonylurea. The NHS advises regular meals and carrying fast-acting carbohydrate.

Diabetic ketoacidosis causes nausea, extreme thirst, confusion, tiredness, stomach pain, fruity-smelling breath and rapid breathing. The SmPC stresses that blood sugar can be only moderately raised in this situation, so do not be falsely reassured by a normal-looking glucose reading. Risk factors include low insulin reserve, pancreatitis, reduced insulin doses and restricted food intake.

Severe urinary or genital infection and Fournier's gangrene (fever, burning urination, back or abdominal pain, genital swelling) need an NHS 111 call. Dehydration (dark urine, dizziness, dry mouth) also needs prompt advice. Anaphylaxis needs 999.

• NHS 111: ketoacidosis symptoms, dehydration signs, genital swelling with fever.

• 999: swollen lips or throat, difficulty breathing, collapse.

The SmPC contraindicates it in people allergic to the ingredients and advises against use in type 1 diabetes because of ketoacidosis risk. Extra caution applies for people aged 75 and over, those on blood pressure medicines or diuretics, and those with cardiovascular disease because of fluid loss and low blood pressure. Gastrointestinal illness is a time to check with your care team. Amputation risk has been seen with a related drug, so foot care is emphasised.

Diuretics add to dehydration and low blood pressure; insulin and sulfonylureas add to hypoglycaemia risk, and lithium levels may fall and need closer monitoring. Rifampicin and phenytoin are not recommended with it. Avoid during pregnancy as a precaution, and do not use while breastfeeding. Driving is minimally affected, but low sugar and dizziness matter.

It is a prescription-only medicine. Suspected side effects can be reported through the Yellow Card scheme.