HUMALOG MIX 75/25 PEN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for HUMALOG MIX 75/25 PEN (HUMALOG MIX 75/25 PEN).
Insulin analog with intermediate-acting insulin (insulin lispro protamine suspension) and rapid-acting insulin (insulin lispro). Binds to insulin receptors, activating glucose uptake, glycogen synthesis, and lipogenesis, while inhibiting gluconeogenesis and ketogenesis.
| Metabolism | Metabolized by insulin-degrading enzyme (IDE) in the liver, kidneys, and peripheral tissues. |
| Excretion | Renal: 30-80% (protamine-insulin complex clearance); Hepatic: 10-20% (degradation by insulinase); Fecal: <1% |
| Half-life | Insulin lispro protamine: 13-16 hours (intermediate component); Insulin lispro: 1-2 hours (rapid component). Clinical context: Steady state achieved after 2-4 days of dosing. |
| Protein binding | ~55% bound to albumin; minor binding to alpha-1 globulins |
| Volume of Distribution | 0.7-1.2 L/kg; reflects distribution into extracellular fluid and peripheral tissues |
| Bioavailability | Subcutaneous: 55-77% (mean ~65%) |
| Onset of Action | Subcutaneous: 15-30 minutes (rapid lispro component); Intermediate component: 1-2 hours |
| Duration of Action | Subcutaneous: 18-24 hours due to protamine suspension; Clinical note: Duration dose-dependent and may be shorter with higher doses of rapid component. |
Subcutaneous injection. Individualized based on metabolic needs. Typical total daily insulin dose: 0.5-1 unit/kg/day divided, with Humalog Mix 75/25 given 15 minutes before meals. Starting dose: 0.2-0.3 unit/kg/day for type 1 diabetes; 0.3-0.5 unit/kg/day for type 2 diabetes. Administer twice daily: before breakfast and before dinner. Dose adjustments based on blood glucose monitoring.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment guidelines for Humalog Mix 75/25. However, renal impairment may reduce insulin clearance, increasing risk of hypoglycemia. GFR <30 mL/min: consider dose reduction and close glucose monitoring. For dialysis patients: dosing should be individualized with careful monitoring. |
| Liver impairment | No specific dose adjustment guidelines for Humalog Mix 75/25. Hepatic impairment may alter glucose metabolism and insulin requirements. Child-Pugh class B or C: use with caution, may require dose reduction due to increased risk of hypoglycemia; monitor blood glucose closely. |
| Pediatric use | Weight-based dosing: 0.5-1 unit/kg/day total daily insulin divided into two injections of Humalog Mix 75/25. Start with 0.2-0.4 unit/kg/day for type 1 diabetes. Administer within 15 minutes before meals. Adjust based on blood glucose. Not approved for children <3 years. |
| Geriatric use |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for HUMALOG MIX 75/25 PEN (HUMALOG MIX 75/25 PEN).
| Breastfeeding | Insulin lispro is excreted in breast milk in negligible amounts (M/P ratio ~0.15). Inhaled or injected insulin is minimally absorbed orally by the infant. Breastfeeding is considered safe, but dose adjustment in the mother may be needed due to increased insulin sensitivity postpartum. |
| Teratogenic Risk | Insulin lispro protamine and insulin lispro (HUMALOG MIX 75/25) do not cross the placenta in significant amounts. No increased risk of major malformations has been observed with insulin use during pregnancy. Poorly controlled diabetes carries greater fetal risk. During first trimester, maintain strict glycemic control; second and third trimesters: risk of macrosomia, polyhydramnios, and neonatal hypoglycemia if maternal hyperglycemia occurs. |
■ FDA Black Box Warning
Never share a Humalog Mix 75/25 Pen between patients, even if the needle is changed. Sharing poses a risk for transmission of blood-borne pathogens.
| Serious Effects |
["Hypersensitivity to insulin lispro or any excipients","During episodes of hypoglycemia"]
| Precautions | ["Hypoglycemia is the most common adverse effect; may be life-threatening.","Changes in insulin regimen may trigger hyperglycemia or hypoglycemia; dose adjustments required.","Hypersensitivity and allergic reactions, including anaphylaxis, have been reported.","Fluid retention and heart failure can occur when used with thiazolidinediones (TZDs).","Monitor glucose closely in patients with renal or hepatic impairment due to altered insulin metabolism."] |
| Food/Dietary | No specific food interactions. However, timing of meals is critical: administer within 15 minutes before a meal. Avoid skipping meals after injection to prevent hypoglycemia. Alcohol may increase risk of hypoglycemia. Consistent carbohydrate intake is recommended to maintain glycemic control. |
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| Elderly patients may have reduced renal function and increased risk of hypoglycemia. Use lower starting doses (e.g., 0.2-0.4 unit/kg/day) and titrate slowly. Monitor blood glucose closely. Avoid aggressive dose escalation. Consider cognitive and physical abilities for injection technique. |
| Fetal Monitoring | Monitor blood glucose levels frequently (before meals, at bedtime, and occasionally postprandial). Assess hemoglobin A1c every 1-2 months. Fetal surveillance: ultrasound for growth and anatomy, nonstress tests, biophysical profiles, and amniotic fluid index as clinically indicated. Monitor for maternal hypoglycemia and ketoacidosis. |
| Fertility Effects | No adverse effects on fertility have been reported in animal studies or human data. Insulin lispro does not impair reproductive function. Optimal glycemic control is essential for fertility in diabetic women. |
| Clinical Pearls | Humalog Mix 75/25 is a biphasic insulin analog containing 75% insulin lispro protamine (intermediate-acting) and 25% insulin lispro (rapid-acting). Administer within 15 minutes before meals. Do not use in insulin infusion pumps. Shake vigorously until uniformly cloudy before use. Onset of action is approximately 15 minutes, peak at 1–2 hours, duration up to 24 hours. Rotate injection sites to avoid lipodystrophy. May cause hypoglycemia, especially if meal is delayed. Not recommended for intravenous use. |
| Patient Advice | Inject within 15 minutes before a meal. · Shake the pen well before each use to ensure proper mixing. · Do not use if the insulin appears clumped or if the pen has been frozen. · Rotate injection sites (abdomen, thigh, buttocks) to prevent skin problems. · Always have a fast-acting sugar source (e.g., glucose tablets, juice) for low blood sugar. · Monitor blood glucose regularly and keep a log. · Do not share pens or needles with others. · Store unopened pens in the refrigerator, but not frozen. Opened pens can be kept at room temperature for up to 28 days. |