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Vetsulin U40 Insulin

Vetsulin U40 Insulin by Merck Animal Health

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General Description:

Insulin is an injectable medication used to control diabetic patients' blood sugar levels. Your veterinarian has chosen this product to most closely match your pet's natural insulin. Special insulin syringes (U-40) will be necessary to administer this product. Review the material below now and each time you refill this prescription.

What is this drug?
  • Insulin is a hormone that is naturally produced by the pancreas. It helps regulate blood sugar. When the body doesn't produce enough insulin or when it is produced but not effective, the result is diabetes. Administration of commercial insulin will slowly release insulin into your pet's body tissue.
  • Insulin is a simple molecule, but they do vary slightly between species. Your veterinarian will choose the best insulin for your pet.
  • Insulin is not a cure for diabetes, but a tool to control blood sugars and alleviate clinical signs
  • Insulin is given by injection under the skin
Reasons for prescribing:
  • Used to control hyperglycemia in dogs and cats with diabetes mellitus
  • This medication will cause the blood sugar to go down
What dogs/cats should not take this medication?
  • The safety and effectiveness in puppies and kittens, as well as breeding, pregnant and nursing dogs and cats has not been evaluated
  • Pets who have stopped eating, are anorexic, vomiting, showing signs of extreme drowsiness or fatigue and/or showing signs of severe ketoacidosis
  • Pets known to have had an allergic reaction to insulin
  • Pets allergic to pork or beef should not use insulin from either of these sources

Veterinary insulin products should be given subcutaneously (under the skin) using a U-40 insulin syringe only. Most human products are 100 units per milliliter, therefore would use a U-100 syringe. Some syringes are marked in units and milliliters. Be sure to use the unit scale.

Consult with your veterinarian to ensure you are using the correct syringe for the product prescribed. Ensure you use the correct syringe or you will likely cause incorrect dosing. Accurate dosing/measuring is critical.

Insulin syringes bought at the drugstore may require a prescription.

Feed your pet, make sure that a reasonable amount has been eaten and then give the insulin. If you think your pet is off food or not eating well, do not give the insulin and notify your vet.

Meals should be approximately equal and fed ~12 hours apart.

Giving the injection:

Just prior to use, shake the vial thoroughly until a homogeneous, uniformly milky suspension is obtained. 

When drawing up the insulin, always hold the bottle vertically to avoid unnecessary bubbles in the syringe. If you get bubbles in the syringe, flick the syringe with fingers until the bubble rises to the top and simple plush the air out of the syringe with the plunger.

Before injecting insulin, allow it to come to room temperature in the syringe. Pull up a handful of your pet's scruff. A triangle of skin is formed. Aim your needle for the center of this triangle and stick in the needle. Do not be shy or the needle will not penetrate the thick skin. Pull back slightly on the syringe plunger to ensure you do not get blood back in the syringe. If you see blood, pull the syringe and start over in a slightly different location. If you do not see blood, press the plunger forward and deliver the insulin dose. Reward your pet!

Remember to rotate the injection sites with each injection.

If there is struggling or your pet escapes and you are not sure if your pet got the entire dose of insulin, do not give more , but wait until the next scheduled dose.

Dosage regimens vary greatly among patients. The goal is to maintain blood sugar levels in an acceptable range over the course of the day, by giving injections once or twice a day (usually twice).

Peak effect is ~4-10 hours after dose is given.

Keeping the sugars in proper range will control your pet's excessive urination and appetite. Trial and error with dosing will be necessary and will be adjusted based upon your pet's blood glucose levels and improvement of other clinical signs.

Further adjustments may be necessary to the pet's diet (high protein/low carbohydrate - cats; high fiber - dogs), body weight or other medications.

Follow any diet or exercise plan developed for your pet by your veterinarian.

Do not give a dose of insulin if the pet is experiencing low blood glucose (hypoglycemia). Common causes for hypoglycemia include: excessive doses of insulin, failure to eat, accidental doubling of insulin dose, strenuous exercise, drug effects.

Do not give insulin if the pet has not eaten for 12-24 hours.

Do not change the pet's food, feeding schedule or exercise schedule once regulated. Unscheduled treats should be avoided.

Lantus is a clear liquid; the other insulins are cloudy when gently mixed. Discard opened bottles after 4 weeks.

Ensure you always have at least two bottles of insulin on hand.

Ensure your pet has fresh, clean drinking water at all times. Monitoring water consumption and urination amount is a good indication of glucose control.

What if dose is missed?

If you miss a dose, give it as soon as you remember it, but if it is within a few hours of the regularly scheduled dose, wait and give it at the regular time. Occasional missed doses are easily tolerated; overdoses can be fatal.

What to tell/ask veterinarian before giving medication?

Talk to your veterinarian about:

  • The signs of diabetes mellitus that you've noticed
  • When will your pet need to be rechecked. Frequent blood glucose tests will need to be done initially to determine the type of insulin to use and the correct dose required. After this has been determined, follow up blood checks will need to be done according to your veterinarian's advice.
  • It is not uncommon for a pet's insulin requirement to change over time. Watch for weight loss, excessive appetite, thirst and urination. An adjustment to the insulin dose may be necessary.
  • The importance of consistent daily injections, consistent weight, diet and exercise and home monitoring
  • Risks and benefits of using this drug

Tell your veterinarian about:

  • If your pet has experienced side-effects on other drugs/products
  • If your pet has experienced digestive upset now or ever
  • If your pet has experienced liver, pancreas, thyroid, adrenal gland or kidney disease now or ever
  • If your pet has experienced any other medical problems or allergies now or ever
  • All medicines and supplements that you are giving your pet or plan to give your pet, including those you can get without a prescription. Your veterinarian may want to check that all of your pet's medicines can be given together.
  • If your pet is pregnant or nursing. Spaying your intact pet will likely be necessary.
Storage and Warnings:

Some insulins need to be refrigerated and others do not. Follow the manufacturer's recommendations. Do not freeze. Protect from light.

Just prior to use, gently roll the vial between the palms of your hands ~10 times. Do not shake.

Do not re-use a syringe. Dispose of all syringes in a ‘Sharps' container or another appropriate puncture-resistant disposal container. Discuss disposal options for this container with your veterinarian.

Do not use any insulin product after the labeled expiration date.

Do not use any insulin that has been frozen or exposed to direct heat or light.

Do not use the insulin if the product has become discolored, has particles in it, or looks different than previous vials.

Discard opened bottles after 4 weeks.

Keep this and all medication out of reach of children and pets. Call your physician immediately if you accidentally take this product.

Pet owners allergic to insulin and/or other antibiotics should avoid handling this drug.

Potential side effects:
  • Pets allergic to pork or beef should not use insulin from either of these sources
  • Allergies are rare, but an allergic reaction would show as difficult breathing, hives, scratching, swollen lips, tongue or face, sudden onset of diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma. If you observe any of these symptoms, contact your veterinarian immediately.
  • Low blood sugar (hypoglycemia) is the most common side effect. It is caused by giving too much insulin, missing or delaying food, changing the food or amount fed, increasing exercise, an infection or illness or a drug interaction.
  • Symptoms include disorientation, weakness, hunger, nausea, rapid heartbeat, lethargy, staggering, cold, possibly seizures and coma. Hypoglycemic cats may simply be inactive. Offer the pet food. If s/he won't eat, give the pet sugar (ex. light Karo syrup) rubbed carefully onto the pet's gums. Swallowing is not necessary as the sugars are absorbed directly through the mucous membranes of the mouth. This should revive the pet within 1-2 minutes. Once your pet has responded and is sitting up, feed s/he a high-protein meal. Contact your veterinarian for the next step(s).
  • High blood sugar (hyperglycemia): notify your veterinarian immediately if the pet experiences drowsiness, dry mouth, flushed dry skin, increased urination, loss of appetite, nausea, vomiting, trouble breathing or unusual thirst.
  • Contact your veterinarian if you notice excessive water consumption for more than 3 days, excessive urination, loss of appetite, weakness, seizures, behavior change, muscle twitching, anxiety, constipation, vomiting, diarrhea, signs of a bladder infection (small, frequent urinations, straining, blood in the urine) or swelling of the head or neck
  • Dogs who are poorly regulated have a greater risk of developing cataracts
  • Females should be spayed as estrus will change insulin requirements
  • If you notice anything unusual, contact your veterinarian
Can this drug be given with other drugs?
  • Yes, but the dose may need to be adjusted. These drugs may interact with insulin: anabolic steroids, alcohol, aspirin and other salicylates, beta-adrenergic blockers, cardiac glycosides, dextrothyroxine, dobutamine, epinephrine, estrogen/progesterone combinations, furosoemide, glucocorticoids, guanethidine, monoamine oxidase inhibitors, phenylbutazone, sulfinpyrazone, tetracycline, thyiazide diuretics and thyroid medications.
  • Do not give any other prescription or over-the-counter drugs, including vitamins, minerals and herbal products, without first talking to your veterinarian.
  • If your pet experiences any unusual reactions when taking multiple medications, contact your veterinarian

Contact your veterinarian immediately if you inject more than the prescribed amount.

What else should I know?

Have your pet wear an identification tag that indicates it is a diabetic. Perhaps include your veterinarian's name and phone number.

Never leave home without sugar or corn syrup. Liquid glucose packets can be bought at your pharmacy. Become very aware of your pet's ‘normal' behavior in order to determine when something is wrong.

There are urine dipstick tests that can help you measure urine glucose. If you detect ketones in the urine, this can be a very bad sign. Contact your veterinarian if urine ketones persist more than a couple of days.

Litter additives that detect glucose in urine are also available.

Notify your veterinarian if your animal's condition does not improve or worsens despite this treatment.

As with all prescribed medicines, insulin should only be given to the dog/cat for which it was prescribed.

This is just a summary of information about insulin. If you have any questions or concerns about insulin or diabetes, contact your veterinarian.

(Humulin, Vetsulin, PZI, Lantus, Glargine)

Common Drug Name


Common Brand Names
Humulin N and Humulin R, Vetsulin (porcine zinc insulin), PZI VET (protamine zinc insulin), Lantus (glargine)

Insulin comes in a glass vial with a rubber stopper. Some types need to be  refrigerated, and others do not. Follow the manufacturer?s recommendations. Do not use the insulin beyond its expiration date. Lantus is a clear liquid; the other insulins are cloudy when gently mixed.

Insulin is used for the treatment of diabetes mellitus.

Insulin Concentrations
The concentration of insulin is measured in units. Insulin is available in concentrations of 40, 100, and 500 units/ml (U/ml). 

Insulin Syringes
There are corresponding syringes to use for the measurement of the three concen­trations of insulin. If using insulin with 40 U/ml, you must measure and administer it with a U-40 syringe; using a U-100 or U­500 syringe would result in the wrong amount of insulin being given, with perhaps a fatal outcome. There may be several types of U-40 syringes available, manufactured to deliver low or high amounts. Find out from your veterinarian (or pharmacist) what syringes are best for you to use with the concentration and amount your pet is receiving.
Insulin syringes are marked in units, and may also be marked in milliliters. Be sure to use the unit scale. 

An insulin syringe has 4 basic parts: the barrel, plunger, needle, and needle guard. Many brands of syringes have the needle permanently attached to the syringe barrel so it cannot be removed.

Measuring a Dose

1. Prior to removing a dose of insulin from the vial, mix the contents by gently rolling the vial be­tween the palms of your hands. DO NOT SHAKE INSULIN as that will cause air bubbles to form, and it will be more difficult to get an accurate measurement. NOTE: We have used a colored solution instead of insulin to better illustrate the steps.

2. Hold the vial stopper-side-down, remove the needle guard from the insulin syringe, and insert the needle of the syringe into the vial through the rubber stopper.

3. Pull back on the plunger of the syringe to draw the insulin into the syringe once, then inject it back into the bottle. Redraw the proper dose back into the syringe. This is helpful in accurately dosing, as insulin may stick to the inside of the plastic syringe or an air bubble may be present in the syringe. If any air enters the syringe, you can also expel that back into the vial by keeping the vial upside down, and the needle of the syringe pointing up.

4. Recheck that you have withdrawn the proper amount of insulin. (See example below for the correct measurement of 15 units). Remove the syringe from the vial and replace the needle guard. You are now ready to give the insulin.

Giving the Injection
To acquaint yourself with what giving an insulin injection may feel like, it is often recommended to practice by injecting water from an insulin syringe into an orange.
To be sure your pet gets her insulin, and does not receive extra doses (from other members of the family who may not know the insulin was given), record the time of each insulin injection on a designated calendar.
When giving your pet an insulin injection, you may, at first, want someone to help you hold and/or distract the pet while you are giving the injection. Usually pets do better if they are not held tightly. Scratching a pet on the head, getting her attention with a toy, or placing an enticing treat (very small piece of cooked chicken) near her nose may help focus her attention away from the injection. The needle is extremely thin, and the injection almost painless.

This information may not cover all possible uses, directions, side effects, precautions, allergic reactions, drug interactions, or withdrawal times.

Rev. 9/14/2007 Always consult your own veterinarian for specific advice concerning the treatment of your pet.
Remove the needle guard from the filled syringe. If you are right-handed, hold the syringe in your right hand. With your left hand, pick up fold of skin along your pet's shoulders (use a different site every time). Some veterinarians recommend giving the injections under the skin on the sides of the chest and abdomen, since it may be better absorbed from these sites.

Push the needle through the skin at about a 45º angle. Be careful not to push the needle through the entire fold of skin and out the other side, or accidentally into your finger.
Pull back slightly on the syringe plunger to be sure the needle is not in a blood vessel (if it is, blood will enter the syringe as you pull back the plunger). If you see blood, pull out the syringe and start over. If no blood is seen, give the insulin by pushing the plunger all the way in with your thumb.
Withdraw the needle from the pet's skin, and replace the needle guard.
Reward your pet by scratching her head, giving her the very small piece of cooked chicken, and/or talking to her. 
Record the time of the insulin injection on the designated calendar. 
Place the needle and syringe in a puncture-resistant container. Follow your local regulations regarding disposal.

Determining the Dose
Always follow the dosage instructions provided by your veterinarian.
Doses vary considerably between animals. In some cases, insulin may need to be given twice a day; it may need to be given at higher doses to get the diabetes under control, then decreased; or doses may need to be increased over time.
If the pet does not receive the entire dose of insulin, (e.g., some leaked out of  the injection site, the needle went through the entire fold of skin and the dose was injected into the air, etc.) do NOT, give more insulin. Wait to give  more insulin until the next scheduled dose. Occasional missed doses are easily tolerated; overdoses can be fatal.

If you miss a dose by more than 2-3 hours, contact your veterinarian to determine if you should still give it. If it is almost time for the next dose, skip the one you missed and go back to the regular schedule. Do not give 2 doses at once. 
This medication should only be given to the pet for whom it was prescribed

Possible Side Effects
Consult your veterinarian if you notice any of the side effects listed below.
May see hypoglycemia (low blood sugar level) with signs such as weakness, lethargy, shaking, seizures, or coma. Hypoglycemic cats may simply be inactive.
May also see hyperglycemia (too much sugar in the blood) where the body increases the blood sugar level. Signs may include increased thirst and urination, vomiting, change in gait, or weakness.
If your pet experiences an allergic reaction to the medication, signs may include facial swelling, hives, scratching, sudden onset of diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma. If you observe any of these signs, contact your veterinarian immediately.

Do not change the pet's food, feeding schedule, or exercise schedule once regulated for that food and schedule.  Avoid semi-moist food due to the high sugar content.
Do not use any insulin that has been frozen or exposed to direct heat or light.
Make sure you are always using the appropriate type of syringe for the type of insulin you have. Keep the packages the insulin and syringes come in so when it is time for a refill, you will be able to check to make sure you have received the correct insulin and syringes.
Dogs that are poorly regulated have a greater risk of developing cataracts.
Females should be spayed, as estrus will change insulin requirements.
Consult with your veterinarian regarding the physical examinations and laboratory testing necessary prior to and during treatment with insulin.

Drug, Food, and Test Interactions
Notify your veterinarian of any other medications, including vitamins and supplements, your pet is taking while your pet is receiving insulin.
Increased risk of low blood sugar may occur if used with anabolic steroids, beta-blockers, monoamine oxidase inhibitors, phenylbutazone, sulfinpyrasone, tetracycline, or salicylates like aspirin.
Increased risk of high blood sugar may occur if used with glucocorticoids, thyroid medications, dobutamine, epinephrine, estrogen/ progesterone combinations, or diuretics.
Hypoglycemic agents such as glipizide may help lower insulin requirements, as may chromium picolate.
Use care when starting treatment for thyroid disorders in a diabetic animal, as insulin needs may change.
Changes in potassium levels may occur when using insulin along with heart medications and/or diuretics.
Follow the feeding schedule described by your veterinarian. Usually, if the pet is on 1 injection a day, feed at least 2 meals: one at the time the insulin is administered and again at the time of day when the blood glucose is at its lowest level. If a pet receives 2 injections a day, generally feed at the time of each injection. If your pet does not eat, contact your veterinarian before giving the insulin.

Signs of Toxicity/Overdose

Low blood sugar (hypoglycemia): Signs include weakness, trembling, muscle twitching, behavior changes, seizures, unresponsiveness, coma, and death.
If the pet is given too much insulin or is showing signs of low blood sugar, contact your veterinarian and feed the pet a normal meal, a sugary food, or rub a small amount of sugar water or light karo syrup on the gums. Do not put anything in the mouth of an unresponsive pet.
Contact your veterinarian immediately if you inject the wrong amount of insulin or your pet experiences any of these signs.
If you know or suspect your pet has had an overdose, or if you observe any of these signs in your pet, contact your veterinarian immediately.
Keep this and all other medications out of the reach of children and pets.

This information may not cover all possible uses, directions, side effects, precautions, allergic reactions, drug interactions, or withdrawal times.  Always consult your own veterinarian for specific advice concerning the treatment of your pet.


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