What is insulin?
Insulin (brand names ProZinc®, Vetsulin®, Caninsulin®, Lantus®, Basaglar®, Humulin®, Novolin®, Humalog®, Novolog®, Levemir®) is a hormone used to treat ketoacidosis, and diabetes mellitus. It is also used to treat high potassium levels (hyperkalemia) in conjunction with other medications.
Its use in cats, dogs, birds, small mammals, and large animals to treat ketoacidosis, diabetes, or hyperkalemia is sometimes off label (extra label). Many drugs are commonly prescribed for off-label use in veterinary medicine.
“Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.
How is insulin given?
- Insulin is typically given by injection under the skin. Follow your veterinarian’s instructions on how to administer the injection under the skin.
- In the hospital/clinic, certain insulins may be injected into the vein.
- Give insulin at the same time each day (e.g., always given immediately after a meal).
- Wash your hands before you administer the medication.
- Follow the package directions on handling the insulin: some insulins should be gently rolled and not shaken, others should be shaken thoroughly. Your veterinary healthcare team will also advise you on how to handle the insulin.
- Inspect the insulin to make sure the solution is clear, or the suspension is a uniform milky solution without particles or clumps. If the solution has clumps or looks different, it may be contaminated, and should not be given.
- Make sure the proper syringe is used for the specific insulin; some insulins use U-40 and some use U-100 syringes. Your veterinary healthcare team will advise you on the proper syringe.
- Measure the dose carefully, as overdoses can be life-threatening.
- Ensure there are no bubbles in the syringe, as this can affect the dose.
Do not give injections in the same skin area each time, as this can cause a skin reaction. Do not give insulin to a pet that is showing signs of low blood sugar (see side effects below).
This medication should take effect within 1 to 2 hours; however, effects may not be noted outwardly, so laboratory tests must be done to evaluate the medication’s effectiveness.
What if I miss giving my pet the medication?
If you miss a dose, contact your veterinarian for advice on when to give the next dose. If you cannot reach your veterinarian and your pet is acting normally and is eating, skip the missed dose and give the next dose at its regularly scheduled time. Never give your pet two doses at once or give extra doses.
Are there any potential side effects?
Insulin may cause the following side effects:
- low or high blood sugar levels (at doses that are too high)
- insulin resistance
- allergic reaction on the skin, at the site of injections
- increased drinking, increased urination, or increased appetite due to high blood sugar
Serious adverse reactions may occur due to low blood sugar levels. If any of the following signs develop, contact your veterinarian immediately:
- weakness, lack of energy
- shaking, twitching, head tilting
- sleepiness, incoordination, stumbling
- seizures
- blindness
- abnormal behavior
- restlessness
- coma
Serious adverse reactions may occur that indicate an allergic reaction. If any of the following signs develop, contact your veterinarian immediately:
- hives
- swelling of the head or neck
- difficulty breathing
If you notice serious side effects, it is an emergency. Follow the emergency instructions below, and take your pet to the veterinarian immediately. This short-acting medication should stop working within 24 hours.
Are there any risk factors for this medication?
Insulin should NOT BE USED in pets having an episode of low blood sugar levels (due to not eating, strenuous exercise, changes in the body’s need for insulin, or effects of other drugs/diseases)
Pork insulins (e.g., Vetsulin®) should NOT BE USED in pets with a pork allergy.
Insulin should be USED WITH CAUTION in pregnant pets.
Are there any drug interactions I should be aware of?
The following medications should be USED WITH CAUTION when given with insulin:
- angiotensin-converting enzyme (ACE) inhibitors
- angiotensin II receptor blockers
- beta-adrenergic blockers
- beta-agonists
- calcium channel blockers
- clonidine
- corticosteroids
- diuretics
- fluoxetine
- fluoroquinolones
- monoamine oxidase inhibitors (MAOIs) (antidepressants)
- niacin
- oral hypoglycemics
- pentoxifylline
- phenothiazines
- sulfonamides
- thyroid hormone
It is important to tell your veterinarian about any medications (including vitamins, supplements or herbal therapies) that your pet is taking before starting any treatment.
Is any monitoring needed with this medication?
- Blood glucose levels must be monitored on a regular basis, especially when first starting this medication. Glucose monitoring tests may include glucose curves, spot glucose testing, fructosamine levels, or at-home urine testing to check for ketones.
- Your pet’s weight, appetite, fluid intake, and urine amounts should also be monitored at the clinic and at home.
- At home, monitor for serious side effects, such as signs of abnormally low blood sugar levels.
How do I store insulin?
- Store unopened insulin in the refrigerator between 2°C and 8°C (36°F and 46°F).
- Protect from temperature extremes such as freezing (less than 2°C or 36°F) or higher temperatures (greater than 30°C or 86°F).
- Protect from direct sunlight.
What should I do in case of emergency?
If an overdose of insulin is suspected based on signs of low blood sugar levels, mildly low blood sugar levels can be treated by offering your pet some of their food. In more severe cases, if your pet is not having an active seizure, you can rub Karo syrup, honey, or another sugar syrup on the gums (do not use sugar substitutes).
If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.
