How to manage a patient with diabetes on human mixtard (insulin) and Oral Hypoglycemic Agents (OHAs) presenting with hypoglycemia and a history of hyperglycemia?

Discharge Medication Management for Hypoglycemia with Glycemic Variability

Immediate Discharge Regimen: Discontinue Premixed Insulin and Simplify

You should immediately discontinue the Mixtard 50/50 (premixed insulin) and transition to a basal-plus regimen, as premixed insulin formulations are associated with unacceptably high rates of iatrogenic hypoglycemia and are not recommended for patients with hypoglycemia risk. 1

Why Mixtard Must Be Stopped

• Premixed human insulin (70/30 or 50/50) has been shown to cause a threefold higher rate of hypoglycemia compared to basal-bolus regimens with insulin analogs 1
• The fixed ratio in premixed formulations cannot be adjusted to address the competing problems of hypoglycemia (HbA1c 5.8%) and previous hyperglycemia (300+ mg/dL) 1
• This patient's HbA1c of 5.8% indicates overtreatment and excessive insulin exposure over the past 2-3 months 1

Recommended Discharge Regimen

Step 1: Calculate Reduced Basal Insulin Dose

• Start with basal insulin (insulin glargine or detemir) at 0.1-0.15 units/kg/day given once daily 1
• This lower dose is appropriate for patients with hypoglycemia risk, good metabolic control (HbA1c <7%), and history of severe hypoglycemia 1
• For a 50 kg patient, this would be approximately 5-7 units once daily 2

Step 2: Add Correctional Insulin Only

• Provide rapid-acting insulin (lispro, aspart, or glulisine) for correction doses only before meals if blood glucose >180 mg/dL 1
• Do NOT give scheduled prandial insulin initially, given the recent severe hypoglycemia 1
• Use a conservative correction scale: 1-2 units for glucose 180-250 mg/dL, 2-4 units for glucose >250 mg/dL 1

Step 3: Review and Adjust Oral Hypoglycemic Agents

• Immediately discontinue any sulfonylureas or glinides if the patient is taking them, as these significantly increase hypoglycemia risk 1, 3
• Continue metformin if no contraindications (renal function adequate, no acute illness) 1
• Consider adding or continuing a DPP-4 inhibitor, which has low hypoglycemia risk and can be safely combined with basal insulin 1

Critical Patient Education Before Discharge

Hypoglycemia Recognition and Treatment

• Provide clear instructions on recognizing blood glucose <70 mg/dL as hypoglycemia requiring immediate treatment 1
• Prescribe oral glucose tablets (15-20g) or glucagon emergency kit for severe hypoglycemia 1, 4, 5
• Instruct on the "15-15 rule": consume 15g fast-acting carbohydrate, recheck in 15 minutes 1, 4
• For severe hypoglycemia without ability to swallow, family should administer 1 mg glucagon intramuscularly or subcutaneously 5

Blood Glucose Monitoring Schedule

• Check fasting glucose daily to guide basal insulin titration 2
• Check pre-meal glucose if considering correctional insulin 1
• Check glucose if any hypoglycemia symptoms occur 1, 3

Insulin Adjustment Instructions

• If fasting glucose <80 mg/dL on 2 or more occasions: reduce basal insulin by 2 units 2
• If fasting glucose 140-179 mg/dL consistently: increase basal insulin by 2 units every 3 days 2
• If any severe hypoglycemia (<54 mg/dL) occurs: reduce basal insulin by 10-20% immediately and contact physician 2, 4

Follow-Up Plan

• Schedule follow-up within 1-2 weeks with primary care physician or endocrinologist 1
• Recheck HbA1c in 3 months to ensure it remains in safe range (target 7-8% given hypoglycemia history) 1
• Consider referral to diabetes educator for comprehensive insulin management training 1, 3

Common Pitfalls to Avoid

• Do not restart the same total daily insulin dose - the HbA1c of 5.8% proves the previous regimen was excessive 1, 2
• Do not use sliding scale insulin alone without basal insulin, as this leads to poor glycemic control 1
• Do not delay discontinuation of sulfonylureas if present, as they are a major contributor to hypoglycemia risk 1, 3
• Do not send the patient home without a glucagon emergency kit and clear instructions on its use 5, 3

Addressing the Glycemic Variability

The pattern of hypoglycemia (50 mg/dL) with previous hyperglycemia (300+ mg/dL) suggests:

• The premixed insulin's fixed ratio was causing excessive insulin at some times and insufficient coverage at others 1
• Possible inconsistent meal timing or carbohydrate intake 4, 3
• The basal-plus approach allows independent adjustment of basal coverage versus meal-related needs 1
• A 2-3 week period of scrupulous hypoglycemia avoidance may help restore hypoglycemia awareness if impaired 6, 3