insulin lispro protamine/insulin lispro (Rx)

Brand and Other Names:Humalog Mix 50/50, Humalog Mix 50/50 Kwikpen, more...Humalog Mix 75/25, Humalog Mix 75/25 Kwikpen

Dosing & Uses


Dosage Forms & Strengths

insulin lispro protamine/insulin lispro

subcutaneous injection

  • (75units/25units)/mL
  • (50units/50units)/mL

Diabetes Mellitus

Combination rapid-onset (faster than regular insulin) and intermediate-acting insulins in fixed dose

Dose regimen varies among patients depending on metabolic needs; typical daily insulin requirements range between 0.5-1 unit/kg

Administer SC BID (ie, before breakfast and evening meal); each dose intended to cover 2 meals or a meal and snack

Inject SC into abdominal wall, thigh, or upper arm

Safety and efficacy not established


Adverse Effects

Frequency Not Defined


Insulin resistance



Local allergic reaction


Injection site reactions

Weight gain








During episodes of hypoglycemia


Never share pen between patients even it needle is changed

Suspension for SC use, do not administer IV

Administer within 15 minutes of meals (rapid onset and peak ~1 hr)

Rapid changes in serum glucose may induce symptoms of hypoglycemia

Early warning symptoms of hypoglycemia may be different or less pronounced under certain conditions (eg, long duration of diabetes, diabetic nerve disease, use of beta-blockers or intensified diabetes control)

Caution in conditions with decreased insulin requirements (eg, diarrhea, nausea, vomiting, malabsorption, hypothyroidism, renal impairment, hepatic impairment)

Caution in conditions with increased insulin requirements (eg, fever, hyperthyroidism, trauma, infection, surgery)

Do not administer via insulin infusion pump

Thiazolidinediones are peroxisome proliferator-activated receptor (PPAR)-gamma agonists and can cause dose-related fluid retention, particularly when used in combination with insulin; fluid retention may lead to or exacerbate heart failure, monitor for signs and symptoms of heart failure and treat accordingly and consider discontinuing thiazolidinediones

Glucose monitoring recommended for all patients with diabetes

Severe, life-threatening, generalized allergy, including anaphylaxis, can occur with insulin products, including this medication; if hypersensitivity reactions occur, discontinue therapy; treat per standard of care and monitor until symptoms and signs resolve

Accidental mix-ups between insulin products can occur; instruct patients to check insulin labels before injection

Severe, life-threatening, generalized allergy, including anaphylaxis, reported; discontinue therapy, monitor, and treat if indicated

All insulin products cause a shift in potassium from extracellular to intracellular space, possibly leading to hypokalemia; untreated hypokalemia may cause respiratory paralysis, ventricular arrhythmia, and death; monitor potassium levels in patients at risk for hypokalemia if indicated (eg, patients using potassium-lowering medications, patients taking medications sensitive to serum potassium concentrations)

Hyperglycemia or hypoglycemia with changes in insulin regimen

  • Changes in an insulin regimen (eg, insulin strength, manufacturer, type, injection site or method of administration) may affect glycemic control and predispose to hypoglycemia [or hyperglycemia
  • Repeated insulin injections into areas of lipodystrophy or localized cutaneous amyloidosis reported to result in hyperglycemia, and sudden change in injection site (to an unaffected area) reported to result in hypoglycemia
  • Make any changes to patient's insulin regimen under close medical supervision with increased frequency of blood glucose monitoring
  • Advise patients who have repeatedly injected into areas of lipodystrophy or localized cutaneous amyloidosis to change injection site to unaffected areas and closely monitor for hypoglycemia
  • For patients with type 2 diabetes, dosage adjustments of concomitant anti-diabetic products may be needed


  • Hypoglycemia is the most common adverse reaction associated with all insulin therapies; severe hypoglycemia can cause seizures, may lead to unconsciousness, may be life-threatening, or cause death
  • Hypoglycemia can impair concentration ability and reaction time, this may place an individual and others at risk in situations where these abilities are important (eg, driving or operating other machinery)
  • Hypoglycemia can happen suddenly and symptoms may differ in each individual and change over time in the same individual; symptomatic awareness of hypoglycemia may be less pronounced in patients with longstanding diabetes, in patients with diabetic nerve disease, in patients using medications that block the sympathetic nervous system(eg, beta-blockers), or in patients who experience recurrent hypoglycemia.
  • The risk of hypoglycemia after injection is related to duration of action of insulin and in general, is highest when glucose-lowering effect of insulin is maximal; as with all insulin preparations, the glucose-lowering effect time course of this medication may vary in different individuals or at different times in same individual and depends on many conditions, including area of injection as well as injection site blood supply and temperature
  • Other factors which may increase risk of hypoglycemia include changes in meal pattern (eg, macronutrient content or timing of meals), changes in level of physical activity, or changes to co-administered medication
  • Patients with renal or hepatic impairment may be at higher risk of hypoglycemia
  • Patients and caregivers must be educated to recognize and manage hypoglycemia; self-monitoring of blood glucose plays essential role in prevention and management of hypoglycemia; in patients at higher risk for hypoglycemia and patients who have reduced symptomatic awareness of hypoglycemia, increased frequency of blood glucose monitoring is recommended
  • Medication errors may cause hypoglycemia; accidental mix-ups between insulin products reported; to avoid medication errors between this drug and other insulins, instruct patients to always check insulin label before each injection; do not transfer Humalog U-200 from the Humalog KwikPen to a syringe; the markings on insulin syringe will not measure dose correctly and can result in overdosage and severe hypoglycemia

Pregnancy & Lactation


The limited available data in pregnant women are insufficient to inform a drug-associated risk of adverse developmental outcomes; published studies during pregnancy have not reported association between drug and induction of major birth defects, miscarriage, or adverse maternal or fetal outcomes; there are risks to mother and fetus associated with poorly controlled diabetes in pregnancy

Poorly controlled diabetes in pregnancy increases maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, stillbirth and delivery complications; also increases fetal risk for major birth defects, still birth, and macrosomia related morbidity

Animal data

  • Pregnant rats and rabbits exposed to drug during organogenesis showed no adverse effects on embryo/fetal viability or morphology in offsprings administered a dose approximately 3 times the human subcutaneous dose of 1 unit insulin lispro/kg/day; no adverse effects on embryo/fetal development were observed in offspring of rabbits exposed to insulin lispro at doses up to approximately 0.24 times the human subcutaneous dose of 1 unit/kg/day


Available data from published literature suggests that exogenous human insulin products, including insulin lispro, are transferred into human milk

There are no adverse reactions reported in breastfed infants in the literature; there are no data on effects of exogenous human insulin products, including insulin lispro, on milk production

Consider developmental and health benefits of breastfeeding along with mother’s clinical need for insulin, any potential adverse effects on breastfed child from therapy or from underlying maternal condition

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.



Bioavailability: SC, well absorbed (2-3 times faster than regular insulin)

Onset: <15 min

Peak Plasma Time: 30-90 min

Protein Bound: 0-9%; similar to regular human insulin

Metabolism: Liver >50%, kidney 30%, adipose tissue/muscle 20%

Vd: 0.26-0.36 L/kg

Mechanism of Action

Binds insulin receptors; activates mechanisms that lower blood glucose by facilitating cellular uptake of glucose into skeletal muscle and fat, simultaneously inhibits glucose output from liver



Humalog Mix 50-50 (U-100) Insulin subcutaneous
100 unit/mL (50-50) vial
Humalog Mix 75-25 KwikPen U-100 Insulin subcutaneous
100 unit/mL (75-25) insulin pen
Humalog Mix 50-50 KwikPen U-100 Insulin subcutaneous
100 unit/mL (50-50) insulin pen
Humalog Mix 75-25 (U-100) Insulin subcutaneous
100 unit/mL (75-25) vial
insulin lispro protamine and lispro subcutaneous
100 unit/mL (75-25) insulin pen
insulin lispro protamine and lispro subcutaneous
100 unit/mL (75-25) insulin pen

Copyright © 2010 First DataBank, Inc.


Patient Handout

Patient Education
insulin lispro protamine and lispro subcutaneous


(IN-sue-lin LISS-pro PRO-tah-meen(NPL)/IN-sue-lin LISS-pro)


USES: Insulin lispro protamine/insulin lispro is used along with a proper diet and exercise program to control high blood sugar in people with diabetes. This product is a combination of two man-made insulins: intermediate-acting insulin lispro protamine and rapid-acting insulin lispro. This combination starts working faster and lasts for a longer time than regular insulin.Insulin is a natural substance that allows the body to properly use sugar from the diet. It replaces the insulin that your body no longer produces, thereby lowering your blood sugar. Controlling high blood sugar helps prevent kidney damage, blindness, nerve problems, loss of limbs, and sexual function problems. Proper control of diabetes may also lessen your risk of a heart attack or stroke.

HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start using this medication and each time you get a refill. If you have any questions, ask your doctor, diabetes educator, or pharmacist.Learn all preparation and usage instructions from your health care professional and the product package.Do not inject cold insulin because this can be painful. The insulin container you are currently using can be kept at room temperature (see also Storage section). Wash your hands before measuring and injecting insulin. Check the product visually for particles, thickening, or clumps before rolling and turning the container. If any are present, discard that container.To avoid damaging the insulin, do not shake the container. Gently roll and turn it between your palms at least 10 times. If using a cartridge or prefilled syringe, turn it upside down so that the glass ball moves from one end to the other. Gently mix the insulin until it appears evenly white and cloudy. If it does not appear this way, discard it.The dosage is based on your medical condition and response to treatment. Measure each dose carefully, and use exactly as prescribed by your doctor. Even small changes in the amount of insulin may have a large effect on your blood sugar.Before injecting each dose, make sure the injection site is clean and dry. Inject this medication under the skin of the abdomen, upper arms, or thighs as directed by your doctor, usually twice daily (15 minutes or less before the morning and evening meal). Do not inject into a vein or muscle. Eat promptly after taking this insulin to avoid low blood sugar (see also Side Effects section). Change where you inject each time to lessen the risk of problems or damage under the skin (for example, pits/lumps or thickened skin). Do not inject into skin that is red, swollen, itchy, or damaged.Do not mix this product with other insulins or use it in an insulin pump.Do not change brands or types of insulin without directions on how to do so from your doctor.Use this medication regularly as directed by your doctor in order to get the most benefit from it. Carefully follow the insulin treatment plan, meal plan, and exercise program your doctor has recommended. Monitor your blood sugar on a regular basis. Keep track of the results, and share them with your doctor. This is very important in order to determine the correct insulin dose.If you are measuring doses from vials, do not reuse needles and syringes. If you are using the cartridges or pens, use a new needle each time. Do not share your pen device with another person, even if the needle is changed. You may give other people a serious infection, or get a serious infection from them. Learn how to store and discard medical supplies safely.Tell your doctor if your condition does not improve or if it worsens (your blood sugar is too high or too low).

SIDE EFFECTS: Injection site reactions (such as pain, redness, irritation) or weight gain may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: signs of low potassium level in the blood (such as muscle cramps, weakness, irregular heartbeat).Too much insulin can cause low blood sugar (hypoglycemia). This effect may also occur if you do not consume enough calories. The symptoms include chills, cold sweats, blurred vision, dizziness, drowsiness, shaking, fast heartbeat, weakness, headache, fainting, tingling of the hands/feet, or hunger. It is a good habit to carry glucose (sugar) tablets or gel to treat low blood sugar. If you don't have these reliable forms of glucose, raise your blood sugar quickly by eating a quick source of sugar such as table sugar, honey, candy, or drinking a glass of fruit juice or non-diet soda. Tell your doctor right away about the reaction. To help prevent low blood sugar, eat meals on a regular schedule and do not skip meals.Too little insulin can cause high blood sugar (hyperglycemia). Symptoms of high blood sugar include thirst, increased urination, confusion, drowsiness, flushing, rapid breathing, or fruity breath odor. If these symptoms occur, tell your doctor right away. Your treatment plan may need to be changed.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or to other insulins; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, liver disease.Do not use this medication when you have low blood sugar.You may experience blurred vision, dizziness, or drowsiness due to extremely low or high blood sugar. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely.Limit alcohol while taking this medication because it can increase the risk of developing low blood sugar.It may be harder to control your blood sugar when your body is stressed (such as due to fever, infection, injury, or surgery). Consult your doctor because this may require a change in your treatment plan, medications, or blood sugar testing.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Check your blood sugar before and after exercise. You may need a snack before exercising.If traveling across more than two time zones, ask your doctor about how to adjust your insulin schedule.Tell your doctor right away if you are pregnant. Pregnancy may cause or worsen diabetes. Discuss a plan with your doctor for managing your blood sugar while pregnant. Your doctor may change your diabetes treatment during your pregnancy (such as diet and medications including insulin).This medication passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding. Your insulin needs may change while breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Many drugs can affect your blood sugar, making it harder to control. Before you start, stop, or change any medication, talk with your doctor or pharmacist about how the medication may affect your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Tell your doctor right away if you have symptoms of high or low blood sugar. (See also Side Effects section.) Your doctor may need to adjust your diabetes medication, exercise program, or diet.Beta-blocker medications (such as metoprolol, propranolol, glaucoma eye drops such as timolol) may prevent the fast/pounding heartbeat you would usually feel when your blood sugar falls too low (hypoglycemia). Other symptoms of low blood sugar such as dizziness, hunger, or sweating are unaffected by these drugs.Check the labels on all your medicines (such as cough-and-cold products) carefully. Some products may contain sugar or alcohol and may affect your blood sugar. Ask your doctor or pharmacist about using these products safely.Other medications can affect the results of urine tests for sugar or ketones. Consult your doctor or pharmacist for more information.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: very fast heartbeat, vision changes, unexplained heavy sweating, agitation, fainting, seizures.

NOTES: Do not share this medication, needles, or syringes with others.Attend a diabetes education program to learn more about how to manage your diabetes with medications, diet, exercise, and regular medical exams. Learn the symptoms of high and low blood sugar and how to treat low blood sugar.Check your blood sugar regularly as directed. Lab and/or medical tests (such as fasting blood glucose, hemoglobin A1c) should be done while you are taking this medication. Keep all medical and lab appointments.Wear or carry identification stating that you have diabetes and are using this drug.

MISSED DOSE: It is very important to follow your insulin regimen exactly. Do not miss any doses of insulin. Keep extra supplies of insulin and an extra syringe and needle on hand. Discuss specific instructions with your doctor now in case you miss a dose of insulin or a meal in the future.

STORAGE: See also the How to Use section.Store all unopened insulin containers in the refrigerator. Do not freeze, and do not use insulin that has been frozen. If you are using the vials, store open vials in the refrigerator or at room temperature away from direct heat and light. Store in the carton to protect from light. Do not refrigerate cartridges or pens that are currently in use. Discard cartridges and vials in use after 28 days, and pens in use after 10 days, even if there is insulin left. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

MEDICAL ALERT: Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).

Information last revised August 2023. Copyright(c) 2023 First Databank, Inc.

IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.



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Tier Description
1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
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Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.