What is the recommended administration schedule for 30 units of Mixtard (biphasic insulin) in an adult patient with type 2 diabetes?

Administering 30 Units of Mixtard (Biphasic Insulin)

For 30 units of Mixtard daily, administer it as a twice-daily regimen with approximately 17-18 units before breakfast and 12-13 units before dinner (roughly 55-60% morning, 40-45% evening split), given 0-15 minutes before meals. 1, 2

Recommended Dosing Schedule

Morning Dose (Before Breakfast)

• Give 17-18 units (approximately 55-60% of total daily dose) 0-15 minutes before breakfast 1, 2
• This higher morning dose addresses the dawn phenomenon and provides coverage through the day 2

Evening Dose (Before Dinner)

• Give 12-13 units (approximately 40-45% of total daily dose) 0-15 minutes before dinner 1, 2
• The lower evening dose reduces nocturnal hypoglycemia risk while providing overnight basal coverage 2

Critical Administration Requirements

Timing and Meal Consistency

• Inject Mixtard 0-15 minutes before meals—never after eating 1, 3
• Take insulin at the same times every day 1
• Eat meals at consistent times daily to match the fixed insulin action profile 1
• Never skip meals, as the intermediate-acting component continues working regardless of food intake 1

Carbohydrate Consistency

• Consume similar amounts of carbohydrates each day to match the set doses of premixed insulin 1
• Premixed insulin lacks the flexibility of basal-bolus regimens—meal timing and content must be predictable 1

Monitoring Requirements

• Check fasting blood glucose and pre-dinner glucose daily during titration 1
• Monitor 2-hour postprandial glucose periodically to assess adequacy of the rapid-acting component 1
• Reassess therapy every 3-6 months with HbA1c measurement 1

Dose Adjustment Guidelines

If Fasting Glucose Remains Elevated

• Increase the evening (dinner) dose by 2 units every 3 days until fasting glucose reaches 80-130 mg/dL 4
• The evening dose primarily controls overnight and fasting glucose 4

If Pre-Dinner Glucose Remains Elevated

• Increase the morning (breakfast) dose by 2 units every 3 days 4
• The morning dose provides daytime basal coverage 4

If Hypoglycemia Occurs

• Reduce the corresponding dose by 10-20% immediately 1
• Treat any glucose <70 mg/dL with 15-20 grams of fast-acting carbohydrate 1
• Recheck glucose 15-20 minutes after treatment and repeat if needed 1

Physical Activity Considerations

• Always carry quick-acting carbohydrates during and after exercise 1
• Reduce insulin dose or increase carbohydrate intake before planned exercise to prevent hypoglycemia 1
• Physical activity timing significantly affects hypoglycemia risk with premixed insulin 1

Critical Pitfalls to Avoid

• Never mix or dilute Mixtard with other insulin formulations 1
• Do not use Mixtard in hospitalized patients—randomized trials show unacceptably high hypoglycemia rates compared to basal-bolus regimens 1
• Avoid irregular meal timing or skipping meals, which dramatically increases hypoglycemia risk with fixed-ratio premixed insulin 1
• Do not continue premixed insulin if flexible meal timing is needed—transition to basal-bolus therapy instead 1

When to Consider Alternative Regimens

• If total insulin requirements exceed 0.5 units/kg/day without achieving glycemic targets, transition to basal-bolus therapy rather than continuing premixed insulin 1
• For patients requiring flexible meal patterns, multiple-daily injection basal-bolus regimens are more appropriate than premixed insulin 1
• Randomized trials demonstrate basal-bolus therapy provides better glycemic control with reduced complications compared to premixed insulin regimens 1

Foundation Therapy

• Continue metformin (unless contraindicated) when using Mixtard, as this combination provides superior glycemic control with reduced insulin requirements 3
• Do not abruptly discontinue oral medications when starting insulin due to rebound hyperglycemia risk 3