Dose, dosage forms and insulin syringe Flashcards
Dosage means
The mass of drug needed per unit weight of the animal (10 mg/kg)
Refers to any animals
Dose means
Specific amount calculated for a specific animal (50mg)
Dosage form is
Physical form of the drug – tablet, liquid, suspension, ointment etc.
Types of dosage forms
Tablets
Capsule, gelcaps
Sustained-release
Suspension
Ointments, creams
Paste
Injectables
Depots/implants
Can you break tablets
Only break if scored
Considered ELDU if split more than intended
What do capsules and gelcaps look like and can they be split
Powdered drugs placed in a gelatin capsule
Opening capsules or dividing capsules is considered ELDU
Sustained release medications are
Tablets or capsules with a special exterior coating that decreases the rate of dissolution
Disrupting the coating is considered ELDU
Suspension medications are
Particles of drug in a liquid; shake before EACH use
Never give suspensions by IV route
Ointments and creams as medications are
Includes drugs with lots of systemic side effects or those that do not have good oral absorption
Things to consider for medication forms
Sometimes we are treating very small animals, so typical dosage forms don’t always work
E.g. can’t split a tablet or capsule into 10 pieces
Sometimes liquids or suspensions can help with this but even then, it isn’t always possible to draw up an accurate dose (eg 0.0004ml can’t be drawn up)
When is it difficult to give certain dosage forms
Sometimes a certain species can be difficult to medicate with a specific dosage form
E.g. it would be hard to apply a topical medication to fish
Rabbits/rodents/birds/most large animals are very difficult (or impossible) to pill (liquid/paste, etc. may be better)
Some cats can also be very difficult to pill
If no on-label drug is available that can be successfully used, this is where extra-label drug use and/or compounding can be very helpful!
Dosage regimen refers to and must include
Refers to the complete information needed
specific amount of drug; number and frequency of administration over a certain amount of time
mass of drug (most commonly expressed as mg)
Route of dosing
Frequency (aka dose interval)
Duration
Example: “Metacam 0.1 mg/kg PO q24h x 5d”
Diabetes mellitus can occur in who and why
Can occur in cats OR dogs
DM = lack of insulin
Recall insulin’s main function is to move glucose out of the blood and into the tissue cells where it can be used for energy.
If there is a lack of insulin, glucose accumulates in the blood and urine and tissue cells are starving for energy (therefore despite eating lots, the animal is losing weight and essentially starving– therefore if the owner is unwilling/unable to treat, it is inhumane to not euthanize).
In DM, insulin is either not being produced or the body does not recognize the insulin.
Type1 diabetes is
Type-1 (insulin dependent diabetes mellitus – IDDM): the pancreas does not produce insulin (because beta-islet cells that normally produce insulin are destroyed by the immune system); autoimmune disease. More common in dogs.
Type 2 diabetes is
Type-2 (non-insulin dependent diabetes mellitus– NIDDM): insulin is produced, but the body does not recognize it; related to obesity, often adult onset (humans). More common in cats.
Results of BG with diabetes
Glucose spills over from blood into urine; sweet urine is great for growing bacteria (increased risk of UTI)
Glucose also osmotically draws water into urine, which is why animals are PUPD
Sugar can accumulate in the lens of the eye (diabetic cataracts, which can lead to diabetic glaucoma in dogs)
Results of diabetic animals being in a starvation state
Fat and muscle are metabolized by ketosis, the by-product of which is ketones (aka acids) that cause acidosis. Diabetic ketoacidosis (DKA) can be fatal.
Neurons can only metabolized glucose, so may see neurological deficiencies (hind end weakness, abnormal behaviour, tremors)
Common presenting signs with diabetes mellitus
Weight loss (in spite of ravenous appetite)
Dehydrated
PU/PD
Plantigrade stance in cats
Treating Diabetes Mellitus
Insulin
Weight loss if obese (esp in cats with Type-2 diabetes)
Decreasing carbohydrates in diet; increasing protein (better digested in diabetics) and soluble fibre (slows down sugar release)
Treating bacterial UTI - antibiotics
Treating cataracts/glaucoma (dogs)
Oral hypoglycemia agents (newer, less commonly used)
Important facts about treating diabetic animals
Most animals with uncomplicated diabetes can be treated as outpatients and managed at home
Fluid therapy may be needed in some cases
Feeding schedule MUST be consistent- consuming the same caloric intake morning and night and from day to day.
Match the glucose-lowering effects of insulin with the glucose-raising effects of the meal, usually a high fiber, low-calorie diet (to slow gut transit time and maintain a stable glucose level throughout the day AND keep the pet from becoming overweight/encourage healthy weight loss).
How do diabetic animals get their insulin
Feed and give insulin at the same time
Insulin is a protein and needs to be refrigerated and handled gently - Gently invert 2-3 times to mix and to prevent denaturation of the protein.
Exception is Caninsulin, which should be shaken at first use.
Keep routine as much as possible to avoid stress hyperglycemia etc.
Know the signs of hypoglycemia (ataxia, coma, lethargy, seizures)
Teach the owner how to handle, store and administer insulin
Types of insulin
Short/rapid insulin
Peak action
Intermediate acting insulin
Long acting insulin
Rapid acting insulin is used for
: molecule is small and rapidly absorbed after SQ injection.
Onset: 0.5-1.5 hrs after injection
Peak action 2-4 hrs
Intermediate acting insulin is
molecule is bigger, leading to slower absorption.
Onset: 1.5-3 hrs
Peak action: 2-11 hrs
Long acting insulin works at and action is how fast
molecule is modified by either attaching another molecule, or changing it’s pH, to allow for a much slower absorption.
Onset: 1-3 hrs
Peak action: 4-26 hrs
The take-away points about insulin types
There are A LOT of insulin types.
It is important that you confirm the brand of insulin being requested.
The action of insulin in each individual animal is very different!
Time of onset and duration varies widely between patients, and is unpredictable.
In veterinary patients, we most often use intermediate or long-acting insulin for daily management of diabetes.
Short-acting insulins are reserved for in-hospital treatment of diabetic animals who are sick.
Insulin in cats
Prozinc (veterinary labeled) and glargine (“Lantus”; human) are the most common in cats. Caninsulin is labeled for use in cats but does not work as reliably and is not the first choice.
Combined with a low carb, high protein diet
Remission rates of 65% or higher have been reported with this combination of diabetic diet and insulin
Watch for signs of remission (decreased pu/pd, increased body weight, less ravenous appetite) so that hypoglycemia doesn’t occur
Serum fructosamine may more useful than a glucose curve (stress hyperglycemia make BG readings unreliable); alternately, clients can be taught to do BG curves at home to reduce the stress of being in clinic.
Diabetes/Insulin in Dogs
Caninsulin (Veterinary labeled Lente insulin) most common; Prozinc recently labelled for use in dogs as well
Often need much higher doses than in cats
Remission much less common than in cats
Diabetic cataracts much more common in dogs than in cats
Glucose curve is and needs to be done how often
Serial blood glucose measurements
Every 1-2 hours
Usually done from immediately before morning dose of insulin until evening dose of insulin
Determines the effectiveness of insulin and can help determine/adjust dose
Must give 1-2 weeks after starting insulin, or after any dose adjustments, before you perform a curve.
Why are glucose curves hard to do for cats in clinic
Difficult to do in clinic in cats due to “stress hyperglycemia”
Teach owners and send glucometer home
Fructosamine
Continuous glucose monitoring (CGM): FreeStyle Libre2
Continuous glucose monitoring is and how often to do each read
A sensor with a flexible catheter is inserted into the skin.
It measures interstitial glucose levels.
Lags behind blood glucose by ~10 minutes.
Measurements are transmitted to owner’s smart phone via an app.
Kept in place by a skin adhesive and a t-shirt to prevent self-removal.
Lasts up to 2 weeks.
Easy for owners to use!
How to dispense insulin
Caninsulin available in 3ml and 10ml vials.
Send home 3ml for small dogs send home 10ml vial for large dogs = about a 1 month supply
Prozinc available in 10ml vial – longer shelf life
Give proper syringes with insulin
How to store insuline
In fridge unopened until expiry date
After opening, in fridge
about 4-6 weeks
Prozinc longer – Good until expiry date whether it is opened or unopened
what syringe should you use for caninsulin
Insulin is dispensed with special syringes
Caninsulin/Prozinc require a U40 syringe
That means 1 ml is divided into 40 units
Each of those units is equal to 1 unit of insulin
Glargine insulin should be used with what syringe
Glargine requires a U100 syringe
That means 1 ml is divided into 100 units
Each of those units is equal to 1 unit of glargine
Can you just use whatever syringe you want for insulin
Syringes are NOT Interchangeable!
Important to communicate this with the client!
Insulin dosing is done by
Dosed by weight in units of insulin/kg.
Some dosing takes into account the severity of hyperglycemia at the time of diagnosis.
Dosages are a starting point. They are adjusted up or down depending on monitoring of glucose levels.
The veterinarian will give you the dose, just like any pharmaceutical.
They are also the ones who adjust the dose – NOT the client!
What are the normal insulin starting doses
Dog starting on caninsulin: dose is 0.5-1 unit/kg every 24 hours.
Cats starting on glargine: dose is 0.25-0.5 unit/kg every 12 hours, not to exceed 2 units per cat BID to start.
How to give insulin and how often
Insulin must be kept in the fridge once opened. Check expiry dates and specific handling instructions on insert for each brand you dispense).
To mix, invert vial completely 2-3 times (ensure bubble goes completely to the top each time)
Inject SQ. Alternate injection sites as scar tissue forming over time will decrease absorption.
Most insulin is prescribed q12h. Give 15 minutes after eating.
If animal doesn’t eat, NO INSULIN! Skip that dose.
Hypoglycaemia is
Insulin causes blood sugar to drop. If the animal doesn’t eat, will risk hypoglycemia.
Acute hypoglycemia is worse than hyperglycemia
Can be fatal
Signs of hypoglycemia include:
Weakness/disorientation/restlessness
Tremors/shivering
Seizures
Loss of consciousness
When is telling owners about hypoglycemia important
Always warn owners that in the event of hypoglycemia due to giving insulin when pet has not eaten, or accidental overdose, to rub sugar or syrup on gums. Err on the side of caution and treat for hypoglycemia.
Cats in remission are at risk of hypoglycemia if their insulin is not stopped.
Human drugs as oral hypoglycemic agents
Action: Work by stimulating pancreatic beta cells to secrete insulin; therefore some pancreatic function is needed
Example: glipizide
Limited success in animals; seldom used
Relatively high potential for side effects
Feline oral hypoglycemic agents are
A new feline product from Boehringer Ingelheim was recently introduced.
Senvelgo (velagliflozin) oral solution
Action: inhibits a glucose transporter in the kidneys that is responsible for reabsorbing glucose, resulting in lower serum glucose levels.
Use is restricted to:
Cats only
Newly diagnosed
Type II diabetic
Not on insulin currently and have never before been on insulin.
