Terminology, drug classes and drug labels Flashcards
The ability to prescribe and dispense is unique to vet med how
We act in two roles: doctors office and a pharmacy
Some see this as a conflict of interest therefore following regulations is critical to ensure thai privilege continues
When we prescribe a medication, it is the right of the client to have it filled at another location if they wish
We may also fill prescriptions for other vets
Some provinces (Alberta) have a specific pharmacy practice category
Prescription means
a written prescription requesting a medication for a patient
Drug label, package insert, product monograph where the term “off label” comes from
Dispensing label means
the label applied to the outside of a dispensed medication
What are perception drugs legislated under
Prescription drug list
Controlled drug and substances act
Narcotic regualtion
benzodiazepines and other targeted substances regulations
How to know if its a prescription drug
Drugs that are included in the Foods and Drugs Act, Prescription Drug List
In canada, all manufacturers labels and packaging have the PR symbol
Aka legend drug
Look for the Pr symbol on original packaging
Check the prescription drug list
And drug used off label is prescription
Any schedule I drug from NAPRAs harmonised drug schedules
How are Pr drugs selected
Selected by 3 principles
1. supervision by a practitioner is necessary
2.the level of the uncertainty respecting the drug, its use or its effects justifies supervision by a practitioner
3: use of the drug can cause harm to human or animal health or a risk to public health and the harm or the risk can be mitigated by a practitioners supervision
Principle 1 of categorizing pr drugs
supervision by a practitioner is necessary
Supervision by a practitioner is necessary for the diagnosis and treatment of a disease or disorder or its symptoms, or, to monitor a disease, disorder or abnormal physical state, or its symptoms, in respect of which the drug is recommended for use, or to monitor the use of the drug
Used in treatment of serious disease or disease easily misdiagnosed by the public
Individualised patient instructions
Their use may mask other ailments
Principle 2 of categorizing pr drugs
the level of the uncertainty respecting the drug, its use or its effects justifies supervision by a practitioner
For example: drugs that are new so there may be unknown adverse effects including potential for addiction, drugs with unknown or severe side effects
Routine animal or laboratory monitoring is required
Principle 3 of categorizing pr drugs
use of the drug can cause harm to human or animal health or a risk to public health and the harm or the risk can be mitigated by a practitioners supervision
For example
Known adverse reactions at therapeutic dose
Lower therapeutic index(i.e., narrow margin b/w therapeutic and toxic dose)
Adjunctive therapy required (drug interactions)
They have contributed to, or are likely to contribute to, the development of resistant strains of microorganisms e.g. antibiotics
Have potential to cause adverse reactions in people
They process a dependence or abuse potential that is likely to lead to harmful non-medical use
3 subclasses of Pr drugs
Narcotics
Controlled
Benzodiazepines and targeted/controlled drugs
3 subclasses of Pr drugs are described as
Defined in the Food and Drug Act
Use, handling and sale of these drugs are strictly regulated by the federal government via the Controlled Drugs and Substances Act
“Under lock and key”
Dangerous
Drugs with very low Therapeutic Indices (TI)
Potential for human abuse and addiction
Street value
Range from illegal street drugs to prescription medications
Opioid analgesics, sedatives, anesthetics, euthanasia drugs
Special ordering, storage and record keeping requirements
NAPRA is and does what
National Association of Pharmacy Regulatory Authorities – Provincial and Territory regulatory bodies
Set consistent conditions across Canada for sale of (human) drugs
Most of the regulations for every-day transactions in human medicine are regulated at the provincial level (provincial law) or through NAPRA regulations
Provincial laws and regulations can be more strict than federal laws
Veterinary medicine does not fall under NAPRA, however, NAPRA does represent best practice for pharmacy and dispensing
Drugs used in veterinary medicine that are human-labelled or handled by a pharmacy/pharmacist do fall under NAPRA
harmonized drug schedule model is
Created by NAPRA
A list of drug classes recognized at the provincial level across Canada
4 drug schedules
4 schedules of harmonized drug schedule model
Schedule 1 –Prescription required (as per Federal regs)
Schedule 2 – No prescription required;restricted access, “Behind-the-counter” e.g. Cough/cold meds with ephedrine
Schedule 3 – Available for self-selection under the supervision of a pharmacist (I.e., pharmacy-only drugs e.g. extra strength formulations or greater than 50/pkg)
Unscheduled- Can be sold anywhere (not just a pharmacy) e.g. travel size package of regular strength Tylenol®
What do you need to do to order epineprhine
To order ephedrine products from WDDC an end use declaration form must be signed annually by the DVM
Vet biologicals include
Vaccines (live, killed bacterin, toxoid)
Colostrum
Antibody products in vitro diagnostics test kits used for prevention of/treatment/diagnosis of infectious disease
Interferon
Vet biologicals mode of action and look like
Mode of action is related to an immunological response
Products contain a Canadian Veterinary Biologics Establishment Licence number
How are biologicals regulated
The federal Health of Animals Regulations [Section 134.2] prohibit the sale of rabies vaccines to non- veterinarians in Canada.
Biologicals are non prescription drugs
Although not Pr vets are not obligated to sell these product ot the public and are still responsible for their advice and recommendations
Ex, acepromazine
Rabies as a biological
Upon request/application exceptions can be made for rabies vaccination
remote areas without veterinary services for temporary rabies vaccination clinics.
trap-vaccinate-release programs run by provincial wildlife officials.
Since rabies vaccination of pets is important to protect people from rabies as well as to protect their pets, many provinces have legislation that require pets be certified vaccinated by veterinarians
What are natural health products
Vitamins & minerals with human label
Herbal remedies
Homeopathic medicines
Traditional medicines such as traditional Chinese medicines
Probiotics (lactobacillus)
Other products like amino acids (lysine) and essential fatty acids (omega-3 fatty acid)
Some personal care products such as antiperspirants, medicated shampoos and mouthwashes
MUST be safe for consideration as over-the-counter (OTC) products and not require a prescription to be sold.
Natural health products require a product license before they can be sold in Canada
How to get a natural health product licensed
Requires submitting detailed information to Health Canada, including:
Medicinal ingredients
Source
Potency
Non-medicinal ingredients
Recommended use(s)
Identification of natural health products
Authorized product labels will bear an eight-digit product license number preceded by the distinct letters NPN (which stand for Natural Product Number)
Homeopathic medicines, are preceded by the letters DIN-HM (which stand for Homeopathic Medicine Number)
The identification number on the label will inform consumers that the product has been reviewed/approved by Health Canada for safety, efficacy and quality.
Natural health products are legislated under
Fall under scope of Natural and Non-Prescription Health Products Directorate (NNDPD)
Natural Health Products:
Market authorization requirements differ from those required for traditional pharmaceuticals, so monitoring and enforcement of conditions of sale are beyond the scope of pharmacy regulatory authorities
NAPRA policy:
Some NHP products are listed in the NDS and will still remain in the schedules, even if they have a Natural Product Number – as reviewed in 2011.
Natural and Non-Prescription Health Products Directorate is
Established 2004
Regulating authority for the sale and distribution of natural health products in Canada
NNHPD role – “to ensure that Canadians have ready access to natural health products that are safe, effective and of high quality while respecting freedom of choice and philosophical and cultural diversity.”
Natural and Non-Prescription Health Products Directorate is responsible for
Product licensing
Clinical trials
Ensuring Good Manufacturing Practices (Safety and quality control)
Adverse reporting
Product labelling (medicinal and non-medicinal ingredient, potency, dosage form, recommended use, risks and contraindications)
Labelling of Natural Health Products must include
Information required on NHP’s includes:
Product name, dosage form and potency
Product license number
Natural Product Number (NPN) or Homeopathic Medicine Number (DIN-HM)
Quantity of product in bottle
Complete list of medicinal and non-medicinal ingredients
Recommended use (including purpose or health claim, route of administration and dose)
Any cautionary statements, warnings, contra-indications, and possible adverse reactions
Any special storage conditions
Probiotic means
The World Health Organization probiotics definition is “live microorganisms which when administered in adequate amounts confer a health benefit on the host.“
Homeopathy means
A system of therapy based on the concept that disease can be treated with drugs (in minute doses) thought capable of producing the same symptoms in healthy people as the disease itself. These dilute amounts could then be used to treat the very symptoms they were known to produce. (from MedicineNet.com)
Licensed Natural Health Products Database is
Similar to Drug Product Database, but:
Provides information about NPN or DIN-HM products
Lists medicinal and non-medicinal ingredients
Gives dosage form(s)
Recommended use(s)
Risks and contraindications
IUPAC Name (IUPAC – international union of pure and applied chemistry) is
Chemical name of a drug
Gives the molecular formula of the drug; never changes
Always listed on the “drug label”
generic name is and includes
Common name
Refers to the active pharmaceutical ingredient
Generic name never changes
Human/veterinary, different countries
Does not indicate the dose format or formulation
USUALLy, starts with “small case” (not capitalized)
Trade names is and includes
Capitalized; followed by a ® (registered) or (trademarked)
Proprietary names that are licensed by a specific drug manufacturer
Refers to a specific drug that has been formulated in a specific manner
Names will change by country
Drug identification number is and inludes
Every prescription and OTC product (including Unscheduled products) containing an active pharmaceutical ingredient has a DIN
The DIN is a specific number provided at the time of licensing that allows the product to be traced back and identified
Every drug with a DIN has a “drug label”
What is the DIN useful for
Active pharmaceutical ingredient(s)
Specific manufacturer
Specific strength (weight or concentration)
Specific dose form (tablet, oral liquid, capsule…)
Specific formulation
Generic equivalents are and include
Aka “generics”
Contains the same active drug as the original licensed drug
Manufacturers cannot produce until the original patent on the licensed trade name drug has expired (up to 20 years)
Generics must contain comparable active ingredients and are usually less costly.
But, not all generics have equal activity. Related to non-medicinal components that may affect drug absorption, and bioavailability in the body
“ Studies have been carried out to prove that Meloxidyl is ‘bioequivalent’ to the reference veterinary medicinal product: this means that Meloxidyl is equivalent to Metacam in the way it is absorbed and used by the body”
Sources of drug info
label/package insert
Compendium
Veterinary drug fomularies
Drug label
Drug label is
Monograph (insert) that comes with every drug
Every drug with a DIN must have a drug label
You should read this the first time you handle a drug!
Drug label contains what
DIN
Trade name, generic, chemical name
Manufacturer and contact info
Labels to indicate class of drug (C, N, T, Pr, R…)
Pharmacology - how the drug works (absorption rates, serum concentration, how the drug is eliminated,…)
Storage and handling instructions
Indications
Precautions, s/e, warnings, contraindications
What should you look for in Storage and handling
Always read this
Look for
Store away from light
Temperature
Room temperature (15-25 C)
Fridge (4 C)
Freeze
Do not thaw
Humidity
Do not shake
Shake before use
Indications for drugs are
Why a drug is to be used
What conditions it has been approved to treat
Must have been part of the testing process for licensing
Indications for drugs include
Conditions (disease or circumstances)
Specific patient type (species, breed, age, food animal or not, lactating)
Recommended dosage (mg/kg) – Can be given as a range or for specific indication
Route of administration
Frequency and duration of treatment
Precautions are
Fairly rare side-effects or mild side-effects
Example - upset stomach from oral antibiotics; mild nausea and dry mouth with hydroxyzine
Warnings on drugs are
More serious or frequent side effects
Example - blood thinner effect of aspirin; renal damage from NSAIDs
Teratogenic effects
The precautions, warnings, and side effect section must include
Must include all effects that were noted during licensing trials
Contraindications are
Conditions in which drug should NOT be used as will cause severe harm
“NEVER”
COntraindications on a drug label may include
Specific health states (i.e., liver damage, heart disease, bleeding)
Pregnancy, lactating animals
If taking other medications that may cause undesirable drug interactions (e.g., counteract, increase adverse effects, increase intended effect)
Veterinary drug label is
Drugs which have been licensed for animal use have a Veterinary Drug Label
Licensing, sale and use of these drugs is regulated by VDD
Veterinary drug labels contains all of the above and,…
“FOR VETERINARY USE ONLY”
List of species for which drug is indicated
Specific instructions for how drug is to be used in each of these species
Withdrawal times (WDT), other regulations related to food residues
Sources of veterinary drug labels
Original labels:
Manufacturer’s website
Drug packaging
Compendium of Veterinary Products
Summarized information based on label (good for general use such as storage and handling, precautions, side-effects):
Drugs.com (be aware of country)
Plumb’s Veterinary Drug Handbook
Withdrawal times means
Duration of time from the last administration of a specific drug until the animal can be sent to slaughter or other products consumed i.e. milk, eggs
It is the amount of time it takes to reach a maximum allowable drug level in the tissues of the animal. This level is determined by Health Canada – Not “0” drug
Applies to ALL drugs (any product with a DIN number) that is administered to food animals
Applies to all classes of drug (OTC and prescription)
Why is following WDTs important
Makes sure there are no significant drug residues in the human food chain
Consequences of drug residues include:
Adverse effects in humans consuming meat/milk/eggs
Allergies (penicillin)
Toxicity
Known physiological effects (may be the intended physiological effect of the drug or an adverse effect)
Antimicrobial resistance in humans
Factors that affect the WDT
Determined by the following:
Rate of drug metabolism and elimination
What are safe levels of drug for incidental ingestion
What tissues are consumed: meat, milk, eggs
Also depends on any factor that affects the plasma drug curve for any drug:
Specific dose given (mg/kg)
Route of administration
Frequency of administration
Liver and kidney function (age, individual animal)
Species
Formulation of the drug
Procaine Pen G - milk 3 d; meat 10 d
Benzocaine Pen G – milk 28 d; meat 30 d
Type of tissue being consumed (milk versus meat)
Procaine Pen G: milk - 3 d; meat - 10 d
Can drugs that are labeled for food animals be used in a manner not described on the Veterinary Drug label?
Drugs without a WDT are used for
Certain drugs do NOT have a labeled WDT
May state: “Not intended for use in food animal species” or not an issue
Certain drugs are BANNED from use in food animals
Regulations for dugs without WDT
C.01.610 No person shall sell any substance having oestrogenic activity for administration to poultry that may be consumed as food.
C.01.610.1 No person shall sell a drug for administration to animals that produce food or that are intended for consumption as food if that drug contains
(a) chloramphenicol or its salts or derivatives;
(b) a 5-nitrofuran compound;
(c) clenbuterol or its salts or derivatives;
(d) a 5-nitroimidazole compound; or
(e) diethylstilbestrol or other stilbene compounds
Canadian Global Food Animal Residue Avoidance Databank (CgFARAD) is and does what
Non-profit organization made up of veterinary pharmacologists (Usask , U of Guelph)
Support for veterinarians (and producers) for determining WDTs for drug/product use which does not have a labelled WDT (e.g., accidental route of delivery, etc)
Recommendations based on research, unofficial reports, data from other countries or equivalent drugs, translating from known data in other species, etc
Liability still falls on veterinarian/producer for not following label.
WT monitored by CFIA via drug residues testing
Communicating WDTs
Must be on dispensing label when dispensing products
SVMA Practice Standards
7B-a Procedure (MA). Prescriptions contain a warning with the required withdrawal period for medications used in food producing animals.
Rationale: The withdrawal period is essential information of which the client must be made aware.
Guidelines: If the prescription is for a drug that has no withdrawal period, this should be noted on the prescription.
WT not yet required for equine dispensing labels
Don’t forget horses going to competition may be tested!
Remind owners to check their competition doping rules.
What is the WDT that should be communicated to the owner/producer?
Withdrawal time for meat is 21 days. Withdrawal time for milk is 10 days. (Do not slaughter for 21 days. Dump milk for 10 days.)
On label means
Using a drug according to the directions on the drug label without deviation
On-label drug use is ALWAYS the preferred method of using a drug
Advantages to on label drug use
Drug is more likely to be effective; known outcome
Decreases risk of known and unknown side effects
Known WDT for food animals
Professional safety net in the event of adverse effects occurring. (In the event of adverse effects, the manufacturer will stand behind the product)
Extra label drug use is
Aka “Off-label” drug use
“The use of a drug product in a manner that is not consistent with what is indicated on the label, package insert, or product monograph of any drug product approved by Health Canada”
Benefits of ELDU
Veterinary market is small, so allows for increased access to drugs that might not be available (i.e., human drugs)
Allows dose adjustment for size of animal
Examples of ELDU
Different species (using a human drug in an animal, using in a dog versus a cat)
Different age group
Use of a drug for a treatment not listed on the drug label (ie.., different indication)
Higher dose; lower dose than recommended
Different route of administration
Greater or lesser frequency
Longer or shorter duration of use than recommended
Splitting more than recommended (quartering a tablet)
Crushing tablets and mixing in food
Diluting drug and keeping it in that form for storage
Turning tablets and capsules into liquids
Turning drugs into “treat” forms so more palatable
What are Disadvantages of ELDU?
Efficacy not established – May not treat patient
Side effects not established – May harm patient
No scientific (or industry) backing if something goes wrong; vet is responsible for any and all complications - Liability
No known WDT – Monetary loss and harm to general public
ELDU of antibiotics may cause resistance
VDD’s Policy on ELDU
Off-label use of any drug should be avoided whenever an approved product is available.
Veterinarians have the privilege of using drugs with a DIN off- label
Veterinarians who choose to make use of a drug in an off-label manner are responsible for the safety of the animals being treated…
…and for any illegal drug residues that are detected in animals and animal products sold for human consumption.
Client should be made aware that the drug is being used off label as this can affect clinical efficacy and increase risk of adverse reactions – ideally written consent, note in medical record.
If a drug product is left with a producer, and is then used off- label, the supervision lies with the veterinarian
Rules for ELDU
ELDU is described in the Food and Drugs Act. Does NOT include products regulated under the Health of Animals Act (i.e., veterinary biologics) or those registered under the Pest Control Products Act (insecticides, pesticides). Thus, ELDU for those products is NOT a professional privilege.
Veterinary biologicals (including vaccines) and pesticides can only be used on-label
Absolute rule: ELDU ALWAYS requires a prescription.
General rule: Avoid ELDU in all food-producing animals.
Responsibilities of ELDU
Always requires a prescription and valid VCPR
Responsibility for all aspects, including safety, adverse reactions, withdrawal times lie with the prescribing vet
Applies to all prescription drugs and OTC medications used off-label
Not permitted for insecticides, pesticides, biologicals (including vaccines)
Best to Avoid ELDU in ALL food producing animals due to questionable WT
Should you use ELDU on food animals
No
Compounding is
Specific type of ELDU
Drug is being altered so it is in a different format than how the manufacturer produced it at the time of sale and/or administration
Requires advanced training to compound as a human pharmacist (e.g., “compounding pharmacies”)
Always requires a prescription that specifically states a compounded format is required
Aka - Always requires permission from the veterinarian
Veterinarian is wholly responsible for any lack of treatment efficacy or side-effects
Is considered ELDU
“Animal drug compounding is the process of combining, mixing, or altering ingredients to create a medication tailored to the needs of an individual animal or a small group of animals, and these drugs can play a critical role in veterinary medicine” FDA May 1, 2023
Examples of compounding
Altering the concentration if a liquid and storing it
Mixing different medications together in a secondary storage container
Taking a capsule and converting to a suspension
Pre-mixing with food and dispensing “medicated treats” or “medicated feed”
Adding flavor drops
Advantages of compounding
Can adjust dose size for variation in patient size
Increase palatability
Addresses limitation in veterinary drugs due to small market
Disadvantages of compounding
Affects the stability of the drug; unknown expiry date
May alter drug efficacy – Drug may not work
May have unknown or increased side effect – Harm patient
When should a compounded drug be used?
No other options exist
There is scientific literature to back up how the drug is compounded
Compounding pharmacies are
Summit Veterinary Pharmacy (Aurora, ON)
Wall Street Pharmacy (Saskatoon)
Queen Street Pharmacy (Saskatoon)
Medicine Shoppe
It is not in the scope of RVT practice to recommend a drug in its compounded form for ease of administration – Must be prescribed in compounded form by the veterinarian
Must communicate to client that the drug is a compounded drug
Hierarchy of vet prescriptions
- Approved Veterinary Drug (On-label)
- Approved Veterinary Drug (ELDU)
- Approved Human drug (ELDU)
- Compounded Drug
- From approved vet drug - ELDU
- From approved human drugs – ELDU
- From raw active ingredient
