How to administer Mixtard (insulin) to a patient with diabetes?

How to Administer Mixtard Insulin

Mixtard should be administered subcutaneously twice daily before meals using proper injection technique, with the vial gently rolled (not shaken) before each dose to resuspend the insulin, and injected at a 90° angle into rotated sites on the abdomen, thighs, upper arms, or buttocks. 1

Pre-Injection Preparation

Storage and Handling

• Store unopened vials in the refrigerator; vials in use may be kept at room temperature to reduce injection site irritation from cold insulin 1
• Avoid extreme temperatures (<36°F or >86°F) and excess agitation to prevent loss of potency, clumping, frosting, or precipitation 1
• Always maintain a spare bottle of each insulin type used 1

Dose Preparation

• Verify the insulin label before each injection to avoid administering incorrect insulin 1
• Ensure hands and injection site are clean 1
• Gently roll the Mixtard vial between palms to resuspend the insulin—do not shake vigorously 1
• Visual inspection should reveal the insulin to be uniformly cloudy (not clear); check for clumping, frosting, precipitation, or color changes that indicate loss of potency 1
• Draw air equal to the insulin dose into the syringe first, then inject into the vial to avoid creating a vacuum 1
• After drawing insulin, inspect for air bubbles and flick the syringe to remove them (bubbles decrease the dose but are not dangerous) 1

Injection Technique

Site Selection and Rotation

• Inject into subcutaneous tissue of the upper arms, anterior and lateral thighs, buttocks, or abdomen (avoiding a 2-inch radius around the navel) 1
• Rotate injection sites systematically to prevent lipohypertrophy, which distorts insulin absorption 2, 3
• Never inject into areas with lipohypertrophy 2

Injection Process

• Most patients can lightly grasp a skin fold and inject at a 90° angle 1
• Thin individuals or children should use short needles (4-mm pen or 6-mm syringe needles are first-line) or inject at a 45° angle to avoid intramuscular injection 1, 2
• Release the skin pinch before injecting 1
• Routine aspiration (checking for blood) is not necessary 1
• Keep the needle embedded in skin for 5 seconds after complete insulin delivery, especially with pen devices 1

Dosing Considerations

Timing

• Mixtard is typically administered twice daily before meals 4
• The timing depends on blood glucose levels, food consumption, exercise, and individual insulin action variables 1

Starting Doses

• For patients with type 2 diabetes requiring insulin, typical starting doses range from 0.1–0.2 units/kg/day 1
• For type 1 diabetes, typical doses range from 0.4–1.0 units/kg/day, with 0.5 units/kg/day as a common starting point 1
• Doses should be individualized and titrated based on self-monitoring of blood glucose results 1

Formulation-Specific Guidance

• Mixtard 30 (30% regular/70% NPH) versus Mixtard 50 (50% regular/50% NPH): Mixtard 50 produces greater post-breakfast glucose reduction and may be more appropriate for patients with significant post-breakfast hyperglycemia 4
• Do not mix Mixtard with other insulins—it is a premixed formulation designed for immediate use 1, 5

Critical Safety Points

Needle Disposal

• Never recap, bend, or break needles as this increases needle-stick injury risk 1
• Dispose of syringes, pen needles, and lancets according to local regulations 1
• While needle reuse is not recommended by manufacturers and is associated with lipohypertrophy, patients who reuse needles should not be subjected to alarming claims of excessive morbidity 2

Avoiding Common Pitfalls

• Do not change insulin species or types without physician approval and patient notification 1
• Avoid intramuscular injections, especially with mixed insulins, as severe hypoglycemia may result 1, 2
• Cleansing needles with alcohol may remove the silicon coating that reduces injection pain 1
• Ensure patients understand hypoglycemia symptoms and treatment as part of comprehensive insulin education 1

Patient Education Priorities

• Patients should receive instruction on self-titration of insulin doses based on glucose monitoring, which improves glycemic control 1
• Education should cover self-monitoring of blood glucose, diet, injection technique, site rotation, and hypoglycemia management 1, 2
• Blood glucose monitoring is integral to effective insulin therapy—fasting plasma glucose values guide basal insulin titration 2