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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Generic drug name: glargine insulin (GLARE jeen)
Brand name(s): BASAGLAR, LANTUS, TOUJEO
GENERIC: not available FAMILY: Insulins
Find the drug label by searching at DailyMed.

Generic drug name: human insulin
Brand name(s): HUMULIN, HUMULIN 70/30, ILETIN, INSULATARD, LEVEMIR, MIXTARD, NOVOLIN, VELOSULIN
GENERIC: not available FAMILY: Insulins
Find the drug label by searching at DailyMed.

Generic drug name: lispro insulin (LYE sproe)
Brand name(s): HUMALOG, HUMAPEN MEMOIR
GENERIC: not available FAMILY: Insulins
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

No information is available on the effects of insulin on the developing fetus from either human or animal studies. Insulin does not cross the placenta, and it is thought that the benefits would outweigh any risk to the fetus. Tell your doctor if you are pregnant or thinking of becoming pregnant.

Breast-feeding Warning

It is likely that this drug, like many others, is excreted in human milk. Because of the potential for adverse effects of insulin on nursing infants, you should consult your physician as to the safety of breast-feeding.

Safety Warnings For This Drug [top]

Glargine insulin must not be diluted or mixed with any other insulin or solution.

Facts About This Drug [top]

Insulin works by regulating the amount of sugar (glucose) in the blood and the speed at which sugar moves into cells. In diabetics, instead of moving into the cells, the sugar accumulates in the blood, resulting in very high blood sugar levels. Diet affects the cells’ need for insulin and the insulin’s ability to lower blood sugar when necessary. Therefore, for insulin to work, a prescribed diet must be followed. Insulin is not a replacement for such a diet.

Too much insulin may cause low...

Insulin works by regulating the amount of sugar (glucose) in the blood and the speed at which sugar moves into cells. In diabetics, instead of moving into the cells, the sugar accumulates in the blood, resulting in very high blood sugar levels. Diet affects the cells’ need for insulin and the insulin’s ability to lower blood sugar when necessary. Therefore, for insulin to work, a prescribed diet must be followed. Insulin is not a replacement for such a diet.

Too much insulin may cause low blood sugar (hypoglycemia). This happens most often in people who are over 60, especially if they have reduced kidney function, and also occurs frequently in young diabetics with type 1, so-called juvenile-onset, diabetes. Risk of suffering from hypoglycemia increase with the following behavior: skipping or delaying meals, exercising more than usual or drinking significant amounts of alcohol.

The first insulin came from animal sources, the pancreases of cattle or swine. Today the majority of insulin used in the U.S. is produced in bacteria using DNA biotechnology. Animal-source insulin differs slightly in chemical structure from that of human insulin. HUMULIN is one brand of human insulin produced using DNA technology and chemically identical to human insulin. Glargine insulin (LANTUS) and lispro insulin (HUMALOG, HUMAPEN MEMOIR), also produced by DNA technology, are modifications of human insulin and are referred to as insulin analogs. Clinical trials show that there is no difference in diabetes control according to the type of insulin used, in either type 1 or type 2 diabetes.

Properly designed clinical trials have shown that strict control of blood sugar in patients with type 1 diabetes using insulin reduces the risk of the serious complications of diabetes.[1],[2]

Although there is an emphasis on stricter glucose control than before, there are still concerns about the hazards of low blood sugar (hypoglycemia) if control is too strict.[3],[4],[5],[6] Overly strict glucose control also resulted in more auto accidents for diabetics, due to sudden episodes of hypoglycemia.[3],[4] Studies conflict on whether severe and frequent episodes of low blood sugar hasten decline in intellectual ability.[7],[8],[5] Prior objections to frequent testing centered on the concern over making people too preoccupied with being ill. Diabetic therapy must be individualized.

Glargine insulin

Glargine insulin is a long-acting insulin analog produced using DNA technology and approved by the Food and Drug Administration (FDA) in April 2000.

In one clinical trial submitted to the FDA in support of glargine insulin’s approval, one measure of eye damage from diabetes (retinopathy) in patients with type 2 diabetes showed a higher incidence with glargine insulin than with NPH insulin (isophane insulin, an older form of long-acting insulin). The difference was 7.5 percent versus 2.5 percent respectively.[9]

The FDA medical officer who reviewed glargine insulin prior to its marketing approval recommended that the professional product labeling for this product say that “no claim of superiority to NPH insulin should be allowed.”[10]

Regulatory actions surrounding glargine insulin

2009: The FDA issued a safety alert based on data from four published studies concerning the use of glargine insulin and a possible risk for cancer in patients using this medication. The FDA is continuing to evaluate safety data to determine and assess if there is a potential link between glargine insulin and this risk.[11]

Public Citizen has reviewed the studies and has found that there are inconsistencies in the data. Based on these inconsistencies, it is not clear that a definite link between glargine insulin and cancer can be concluded.[12]

2011: In January, the FDA issued safety information stating that it has reviewed the studies on glargine insulin and has found that the evidence available does not show that the reported risk of cancer is linked to glargine insulin use. The FDA will continue to review information.[13]

Human insulin

Human insulin (HUMULIN, HUMULIN 70/30, INSULATARD, MIXTARD, NOVOLIN, VELOSULIN) produced by DNA technology is formulated in a number of different forms to alter both its onset and duration of effect. These forms may also be mixed, under the instruction of a physician or diabetes educator, to better individualize blood sugar control.

Lispro insulin

Lispro insulin has a more rapid onset of action and shorter duration than human insulin. Some cases of resistance to human insulin have been successfully treated with lispro insulin.[14] According to a meta-analysis of trials comparing lispro insulin with human insulin, lispro insulin does not alter the risk of hypoglycemia.[15] In practice, lispro insulin can be administered just before meals, which is an advantage over human insulin, which has to be administered 30 to 45 minutes before meals.

Before You Use This Drug [top]

Tell your doctor if you have or have had:

  • allergies to insulins
  • adrenal or pituitary gland problems[3]
  • eating disorders
  • kidney or liver problems
  • loss of consciousness
  • nausea, vomiting, or diarrhea, or other stomach disorders, especially delayed stomach emptying
  • severe infections
  • severe injuries or surgery
  • thyroid problems
  • changes in female hormones
  • high fever
  • psychological stress
  • pregnancy or are breast-feeding

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Know the warning signs of low blood sugar, high blood sugar, and ketoacidosis (see Adverse Effects).
  • Keep sugar on hand. Tubes or tablets of glucose, a piece of fruit, pure orange juice, cheese, soda crackers, or one or two cups of milk will suffice. Honey, sugar candy, or syrup can also be used. Carry some with you at all times. Avoid chocolate, which is high in fat.
  • Monitor your blood glucose. All diabetics should be using a machine to monitor blood glucose. Be sure you receive adequate instruction. Do not hesitate to ask or repeat questions until you feel comfortable using the device.
  • Eat a diet high in complex carbohydrates and fiber, but low in saturated fats. Avoid sugar, alcohol, and smoking. Distribute your calories over several small meals, or meals and snacks, to prevent low blood sugar. While these general diet guidelines should help, older diabetics should be aware that little information is available on the effect of diets in the elderly.
  • Whenever you cannot eat properly due to illness (fever, nausea, vomiting), continue your insulin, but realize your insulin requirements may change. Close medical supervision and hospitalization may be required. Also, not taking enough insulin, skipping a dose, getting less exercise, overeating, or not eating the right foods can affect insulin requirements.
  • If you plan to have any surgery, including dental, tell your doctor that you are diabetic and take insulin.
  • Carry identification stating your condition and the type of insulin(s) you use.
  • When you travel, pack an extra supply of insulin, syringes, glucose and ketone testing materials, snacks, and a prescription. Carry your supplies with you instead of checking them.
  • Exercise regularly. Inconsistent exercise risks low blood sugar on days you exert more.
  • Keep your feet clean, warm, and dry. If you cannot cut your toenails yourself, find a community group that provides the service. Call your doctor if signs of infection appear.
  • Wear well-fitting shoes and break them in gradually. Avoid thongs, chemical corn and callus removers, and hot soaks or pads.
  • Be cautious while driving. Do not drive when your glucose levels are unstable.
  • Choose nonprescription drugs and vitamins without sugar and alcohol. Lists of acceptable products are generally available from diabetes associations, your doctor, and your pharmacy. Check with your doctor if you have any doubts.

How to Use This Drug [top]

  • Select the syringe of proper units of measure for the amount of insulin you need. The syringe should be made to measure insulin in units to facilitate accurate measurement of the dose of insulin. A 3/10 cubic centimeter syringe measures up to 30 USP (United States Pharmacopoeia) units of insulin. A 1/2 cubic centimeter syringe measures up to 50 USP units, and a 1 cubic centimeter syringe measures up to 100 USP units.
  • If you cannot see well enough to measure the insulin, contact community agencies to find someone to predraw your insulin.
  • Insulin is stable for two weeks in plastic syringes; in glass, it is stable for one week when refrigerated.[16]
  • Verify the label on your insulin and examine the appearance of the insulin. Do not use regular insulin if it is cloudy or thick. Other insulins should appear uniformly milky, but not lumpy, grainy, stuck on the bottle, or unable to shake into suspension. Return questionable, unopened vials to your pharmacy.
  • Wash your hands. Swab the top of the vial with alcohol.
  • Except for regular (short-acting) insulin, roll the vial slowly between the palms of the hands until the insulin is uniformly mixed.
  • Do not shake vigorously, or bubbles may interfere with a correct measurement of insulin.
  • Draw air into the syringe equal to your insulin dose. Insert needle into the vial, then expel the air. Draw insulin into the syringe; check for air bubbles. Double-check your dose.
  • If you use more than one type of insulin, always draw in the same order. Draw regular (short-acting) insulin first. Before injecting, roll the syringe to remix. Several premixed insulins are now available. Do not mix buffered insulins with lente (longer-acting) insulins. Store prefilled syringes of mixtures vertically with the needle upward to avoid plugging the needle.
  • Select a site to inject insulin in the abdomen, buttocks, front thigh, or back of the arm. Stick to one area, then rotate sites within that area to prevent breakdown of fat tissue.[17] Maintain the same posture each time you inject. Avoid inflamed or infected sites.
  • Clean the site before injecting. Inject needle at a 90-degree angle just under the skin (subcutaneously). Pull back on the plunger. If blood appears, try again. Inject in less than five seconds. Massaging the site after injection may speed absorption of the insulin.[18]
  • Insulin comes in a variety of forms with different lengths of action. Do not change brands, strength, or type of insulin without checking with your doctor. Switches may call for a change in your insulin dose. If you use a less common form of insulin, deal with a pharmacy that promises to keep some in stock.
  • Refrigeration prolongs stability and prevents contamination of insulin. According to the International Diabetes Institute, unopened insulin, properly stored, loses 5% potency in 10 years.[19] Insulin (even old-style) may be stored at room temperature. Once assembled, NovolinPen or PenFill must be stored at room temperature and must not be refrigerated.
  • Today, at home, most people with diabetes refrigerate insulin vials until opened, then store the vial being used at room temperature. Do not expose to high temperatures or sunlight. Never freeze insulin or warm it in a microwave. Once opened, vials should be discarded after several weeks.[20] Policies for storing insulin in congregate living and institutions may differ from home practices.
  • Dispose of your syringes according to local waste disposal regulations.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

alcohol, ARMOUR THYROID, ATROMID-S, clofibrate, fenugreek, guanethidine, INDERAL, INDERAL LA, ISMELIN, LEVOTHROID, levothyroxine, NARDIL, oxytetracycline, phenelzine, propranolol, SYNTHROID, TERRAMYCIN, thyroid, timolol, TIMOPTIC.

In addition, the 2003 edition of the USP’s (United States Pharmacopoeia’s) Drug Information for the Health Care Professional lists these drugs as having interaction of major significance: the family of drugs known as beta-blockers, which includes propranolol (INDERAL, INDERAL LA)

Corticosteroids, which include drugs such as prednisone (DELTASONE, METICORTEN).

Adverse Effects [top]

Any insulin may cause allergies in a few individuals.[21],[22] Skin cleansers and preservatives in the insulin also can cause local allergic reactions.

Call your doctor immediately if you experience:

  • signs of low blood sugar: anxiety, blurred vision, cold sweats or cool, pale skin, confusion, difficulty concentrating, drowsiness, increased hunger, headache, nausea, nervousness, numbness, nightmares and restless sleep, rapid heartbeat, shakiness, slurred speech, unsteady walk, abnormal tiredness or weakness, behavior change similar to drunkenness, seizures
  • signs of high blood sugar: blurred vision, drowsiness, dry, flushed skin, breath smells of fruit, increased urination, loss of appetite, tiredness, abnormal thirst, deep, rapid breathing, dizziness, dry mouth, headache, stomachache, nausea, vomiting
  • allergic reactions: itching, rapid heartbeat, shortness of breath, swelling at injection site
  • out-of-control blood sugar
  • weight gain
  • severe vomiting
  • seizures
  • faintness or unconsciousness
  • depressed or thickened skin at injection site
  • swelling of face, fingers, feet, or ankles

Low blood sugar

  • Low blood sugar can be caused by missed meals, increased exercise, consuming alcohol, changes in insulin dose, use of long-acting insulins, use of continuous infusion pumps,[6],[21] and certain illnesses.[3] An increase of even one unit of insulin can cause low blood sugar.[23]
  • Hunger, sweating, and trembling are signs most diabetics rely on as a warning.[24],[25] However, warnings vary with the individual, and whether or not an insulin pump is used. Warning signs may change if low blood sugar occurs often.[5]
  • Every instance of these symptoms does not mean you have low blood sugar. Do not rely only on warning signs, but also test your blood sugar to see if it actually is low, if time permits.[3]
  • More than half of episodes of low blood sugar happen during the night.[6] Testing blood glucose at bedtime is advisable.[5] So is keeping a source of sugar by your bed. However, you may not always be aware of low blood sugar that happened during the night. Clues on waking up are:[17] morning headaches, night sweats, symptoms of hypothermia.
  • If you have low blood sugar often, call your doctor.

High blood sugar

  • Symptoms of high blood sugar in the elderly may vary but they can include: blurred vision, drowsiness, dry, flushed skin, breath smells of fruit, increased urination, loss of appetite, tiredness, abnormal thirst, deep, rapid breathing, dizziness, dry mouth, headache, stomachache, nausea, vomiting, swelling of feet and legs.[17]
  • High blood sugar is often due to severe lack of insulin or infection.

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug and how often they should be done:

  • blood levels of glucose, ketones, and potassium
  • blood pH
  • blood pressure
  • glycosylated hemoglobin
  • urine ketone

last reviewed June 30, 2021