Achieving Effective Glycemic Control

The goals of managing feline diabetes mellitus include:

• Controlling the clinical signs of hyperglycemia (polyuria, polydipsia) .
• Avoiding hypoglycemia.
• Obtaining blood glucose curve values in the desired range:*
  • Cats: 6.7-16.7 mmol/L (120-300 mg/dL) over the course of the day, with a nadir between 5.6-6.9 mmol/L (100-125 mg/dL).

*In the US clinical study, glycemic control was considered adequate if an acceptable blood glucose curve was achieved (i.e., reduction in hyperglycemia and a nadir of 60–160 mg/dL (3.3-8.9 mmol/L)), however, the Merck Animal Health US Technical Services department believes that a nadir below 100 mg/dL (5.6 mmol/L) in cats may warrant a decrease in the dose. Further adjustments in dosage may be necessary with changes in the cat’s diet, body weight, medications, or if the cat develops concurrent infection, inflammation, or other medical disorder.

Important Dosage Information

Doses of insulin are measured in units: 40 IU/mL insulin contains 40 International Units (IU) per milliliter (mL) (1 mL = 1 cc).

Because Caninsulin® has a concentration of 40 IU per mL of solution, a U-40 insulin syringe or VetPen® must be used to achieve correct dosing. Use of a syringe other than a U-40 (or use of a 100 UI/mL cartridge or human insulin pen) will result in incorrect dosing. U-100 syringes and human insulin pens will deliver less than half the required Caninsulin® dose.

Conversely, if a client uses a U-40 insulin syringe or VetPen® with a 100 IU/mL insulin preparation, he or she would inject about two and a half times the amount of insulin needed. This could cause fatal hypoglycemia.

Strongly encouraging clients to purchase Caninsulin®, U-40 insulin syringes, and VetPen® from your veterinary hospital is the best way to protect your patients from incorrect insulin dosing. Remind your clients that using U-100 syringes and insulin pens from a human pharmacy to administer Caninsulin® will result in incorrect insulin dosing, which puts their pet in danger of experiencing serious health consequences.

Preparing the Dose

After washing your hands, take the Caninsulin® (porcine insulin zinc suspension) vial out of the refrigerator. Shake the vial until the insulin is uniformly milky, allowing any foam to disperse.

1 – Carefully remove the cap from the needle and insert the needle into the vial.

2 – Turn the vial upside down, making sure the tip of the needle remains in the vial.

3 – Withdraw the correct dose into the U-40 insulin syringe.

4 – Before removing the needle from the vial, check the syringe for any air bubbles.

5 – If bubbles are present, hold the syringe up and tap its side until the bubbles float to the top. Push them out with the plunger and withdraw the correct dose.

6 – Remove the needle from the vial.

Giving the Injection

1 – Injection should be given under the skin, 2 to 5 cm (3/4 to 2 inches) from the middle of your cat’s back, varying from behind the shoulder blades to the middle of the back region and alternating sides.

2 – Gently insert needle in center of folded skin.

3 – Push plunger until all of the insulin is given.

4 – Pull needle out and dispose of syringe into appropriate sharps collector.

Injection Tips

• Injection site can depend upon what is best for the client and their cat.

• Alternate injection site between left and right side for comfort and best results. Repeat injections at the same site can lead to ineffective treatment.

• Instructing clients to record the location of administration can help assure site rotation.

• If only a partial dose is given, do not attempt to re-dose. Wait and give the cat their usual dose at the next injection time.

Inserting Cartridge in VetPen^®

1 – Wash your hands.

2 – Remove cap and unscrew body from cartridge holder. Remove the used cartridge if needed.

3 – Ensure plunger is retracted. If it is not, rewind plunger to retract.

4 – Insert cartridge after turning the new cartridge up and down at least 10 times until the insulin appears uniformly milky.

5 – Screw cartridge holder and body together gently but firmly.

6 – Peel off protective film and screw new VetPen® needle onto cartridge holder.

7 – Remove outer protective needle cap.

8 – Replace the pen cap then shake the pen until a homogenous, uniformly milky suspension is obtained.

Priming the VetPen^®

It is important to remove the air from the cartridge before use to avoid injection of air and ensure proper dosing.

1 – Dial one unit on the dose selector and remove the needle cap and the inner protective needle sheath.

2 – Hold the pen with the needle pointing up and tap the pen gently with your fingers to push any air bubbles to the top.

3 – Push down the release button and hold until the arrow on the body returns to the starting line on the dose selector.

4 – Repeat steps 1-3 until a strong, steady stream or jet of insulin appears at the needle tip. Expect to expel at least 8 units of air.

5 – Push down the release button and hold until the arrow on the body returns to the starting line on the dose selector.

6 – Check that the cartridge is free of air bubbles by viewing the cartridge through the VetPen window and inverting or tilting the pen.

7 – Ensure the arrow on the VetPen points to the start line on the dose selector, then dial the number of units prescribed.

8 – The VetPen is now ready for use.

Giving the Injection

1 – The injection must be made subcutaneously 2 to 5 cm (3/4 to 2 inches) from the dorsal midline, varying from behind the scapulae (shoulder) to the mid-lumbar region (mid-back) and alternating sides. Rotate the injection site to minimize the pet’s discomfort.

2 – Remove needle cover and protective caps. Insert the needle under the skin, then push the release button toward the pen needle and hold it in place until the start line on the dose selector returns to the arrow on the pen body. Take care to not impede the motion of the dose selector.

3 – After the dose selector has returned to the start line, wait a minimum of 5 seconds before withdrawing the needle from the skin.

4 – If insulin leaks out of the pen after injection, check the cartridge for small air bubbles using the VetPen window. Do not attempt to re-dose.

Injection Tips

• If only a partial dose is given, do not attempt to re-dose. Wait and give the cat its usual dose at the next injection time.

• If you over-dial, never wind back the dose selector. This can damage or break the VetPen and result in inaccurate dosing. Dispose of the insulin and dial up the correct dose.