Hypoglycaemia Medication Adjustment

Hypoglycaemia medication adjustment is the review and change of glucose lowering drugs after a low glucose event so that the cause is removed and recurrence is prevented. Level 1 is glucose under 3.9 mmol/L, level 2 is under 3.0 mmol/L, and level 3 is a severe event needing another person’s help. Any level 2 or 3 event requires a dose change.

Common causes. Missed or delayed meals, extra exercise, alcohol, insulin dose errors, sulphonylureas, falling kidney function, weight loss, a drug interaction (co-trimoxazole, fluconazole, fluoroquinolones), adrenal insufficiency, liver failure, and tight targets in frail patients.

Hypoglycaemia unawareness. Repeated lows blunt warning symptoms. Avoiding all lows for 2 to 3 weeks can restore them.

Immediate treatment (conscious). 15 to 20 g of fast-acting carbohydrate (for example 150 to 200 mL of fruit juice or 3 to 4 glucose tablets), recheck in 10 to 15 minutes, repeat if glucose is under 4 mmol/L, then give a longer-acting snack.

Immediate treatment (unconscious or unable to swallow). Glucagon 1 mg intramuscularly or subcutaneously (0.5 mg in children under 25 kg or under 6 years), or 20% glucose 75 to 100 mL intravenously over 15 minutes, or 10% glucose 150 to 200 mL intravenously.

Sulphonylurea poisoning or recurrent hypoglycaemia. After glucose, octreotide 50 micrograms subcutaneously every 6 to 8 hours for 24 hours may be added, with glucose monitoring for 24 hours.

Replacing drugs. Replace a sulphonylurea with a DPP 4 inhibitor, SGLT2 inhibitor, GLP 1 receptor agonist or pioglitazone. Replace human insulin with an analogue when nocturnal lows persist.

Sulphonylureas. Reduce the dose by 50% after level 1 events, and stop after any level 2 or 3 event. Gliclazide is preferred over glibenclamide if a sulphonylurea must continue.

Basal insulin. Reduce by 10 to 20% (about 4 units) for fasting or nocturnal glucose under 4 mmol/L. After a severe event, reduce by 20 to 30%.

Mealtime insulin. Reduce the dose by 10 to 20% for lows after meals, adjust the carbohydrate ratio, or give the dose after eating if intake is unpredictable.

Correction doses. Switch to the sensitive scale, and avoid correction at bedtime.

Premixed insulin. Reduce the dose by 10 to 20% and move the evening dose to the evening meal; consider changing to basal insulin with another agent.

Targets. Relax the HbA1c target to 58 to 64 mmol/mol (7.5 to 8.0%) in older adults and those with recurrent lows.

Technology and prevention. Offer continuous glucose monitoring with alarms, and review injection sites for lipohypertrophy, which can cause erratic absorption.

Special groups. - Kidney impairment: reduce insulin by 25% when eGFR is 10 to 50 and avoid glibenclamide. - Liver disease: reduce insulin and avoid sulphonylureas in decompensated disease. - Pregnancy: lows are common in the first trimester; reduce insulin and keep tight targets. - Alcohol: take carbohydrate with alcohol, and do not omit meals. - Driving: check glucose before driving and do not drive when under 5 mmol/L.

Monitoring. Review capillary glucose or continuous glucose monitoring data for 1 to 2 weeks after each change. Repeat HbA1c at 3 months. Recheck kidney function and weight.

Stopping. Stop a drug that has caused a severe event unless the cause is clearly reversible.

Referral and escalation. Admit for sulphonylurea hypoglycaemia that recurs, for severe events with seizure or coma, or for unexplained hypoglycaemia without diabetes drugs, where investigation for insulinoma, adrenal insufficiency or liver disease is needed.