Pharmacology
Study of drugs
Pharmacotherapy
Treatment of disease with medicines
Pharmacotherapeutics
Field of medicine that studies drug use in the treatment of disease
Pharmacokinetics
Describes the "motion of drugs" and is used to indicate the study of the ABSORPTION, DISTRIBUTION, METABOLISM, and EXCRETION of drugs
Pharmacodynamics
Study of the mechanisms of action of a drug
Food and Drug Administration (FDA)
- Government agency that enforces the federal Pure Food and Drug Act of 1906
- This act established standards for drug strength, purity, and guidelines for drug labeling
Food, Drug and Cosmetic Act
Congress passed the federal Food, Drug and Cosmetic Act of 1938 which required that a drug be adequately tested to demonstrate its safety when used as its label directs
The Center for Veterinary Medicine (CVM)
Ensures that approved veterinary medicines will not harm animals, or at least that the harm a drug produces will be outweighed by its benefit
1968 Amendment to the Food, Drug and Cosmetic Act
- Requires a drug manufacturer to demonstrate that its drug is safe for animals and does what the label claims
- Provides a reliable method to detect drug residues in food derived from animals
- Provides an acceptable drug withdrawal period
Over-the-Counter Drugs
Are available without a prescription for treating a variety of conditions
Prescription Drugs
- Are regulated by the FDA
- Are limited to use under the supervision of a veterinarian or physician
- Before a prescription drug can be prescribed for an animal, a veterinarian/client/patient relationship (VCPR) must exist
Extra-Label Drug
- Animal Medicinal Drug Use Clarification Act
- Defined as the use of a drug in a manner not specifically described on the FDA-approved label
- This extra-label use must also not result in drug residues in food-producing animals
Controlled Substances
- Some drugs are classified as controlled substances, or drugs considered dangerous because of their potential for human abuse or misuse
- The FDA studies the controlled substances and determines its abuse potential and the Drug Enforcement Agency (DEA) e
Controlled Substances Act
- The Controlled Substances Act classifies a drug into one of five schedules based upon the drug's potential for harm and abuse relative to its medical benefits
- The higher the drug's schedule, the lower the risk of abuse potential
Controlled Substance
Schedule I (C-II)
Substance has a high potential for abuse and has no currently accepted medical use; there is a lack of accepted safety for use (considered most dangerous, with virtually no medical benefit)
- Examples:
- Heroin
- LSD
- Marijuana
Controlled Substance
Schedule II (C-II)
Substance has high potential for abuse but has currently accepted medical use; with severe restrictions
- Examples:
- Cocaine
- Morphine
- Amphetamines
- Pentobarbital
- Etorphine
- Fentanyl
- Codeine
Controlled Substance
Schedule III (C-III)
Substance has potential for abuse less than schedule I and II drugs and has accepted medical uses
- Examples:
- Acetaminophen/Codeine combinations
- Ketamine
- Thiamylal, Thiopental (Barbituates that cannot be given to greyhounds/sight hounds due to their
Controlled Substance
Schedule IV (C-IV)
Substance has low potential for abuse relative to drugs in schedule III and has accepted medical uses
- Examples:
- Diazepam
- Phenobarbital
- Butorphenol
Controlled Substance
Schedule V (C-V)
Substance has low potential for abuse relative to drugs in schedule IV and has accepted medical uses
- Examples:
- Buprenophrine
- Diphenoxylate
- Codeine
- Cough syrups
Records of Controlled Drugs
The registered Veterinarian and other authorized handlers must keep records of orders, receipts, uses, discards, and thefts of controlled substances for TWO YEARS
Veterinary Drug Development
- Discovering and developing safe and effective medicines is a long, difficult, and expensive process
- It can typically take an average of SEVEN YEARS of testing and millions of dollars to bring a new veterinary drug to market
Stages of Veterinary Drug Development
The four stages in drug development:
1. Synthesis/discovery of a new drug compound (preliminary studies)
2. Safety/effectiveness evaluation (preclinical studies and clinical trials)
3. Submission and review of the New Animal Drug Application (review by FD
The Green Book
The Green Book is a list of animal drug products published and updated monthly by the Drug Information Laboratory
Regulatory Agency:
Food and Drug Administration (FDA)
Area of Regulation:
Development and approval of drugs
Regulatory Agency:
Environmental Protection Agency (EPA)
Area of Regulation:
Development and approval of topical pesticides (i.e. flea products)
Regulatory Agency:
United States Department of Agriculture (USDA)
Area of Regulation:
Development and approval of biologics such as vaccines and antitoxins
Carcinogenicity
The ability or tendency to produce cancer
Teratogenicity
The capacity to cause birth defects
Short-Term Tests
Occur in the hours following a test dose, to check the animal for such obvious adverse reactions such as seizures, paralysis, depressed breathing, depressed heart rate, and death
Long-Term Tests
Run for 3 to 24 months of repeated dosing to check for toxicity damage
Special Tests
Tests done to determine reproductive effects, carcinogenicity, or teratogenicity, are both short and long term
Toxicity Evaluation
Is done to determine the dose at which a drug induces organ or tissue damage that may, at a high-enough dose, result in permanent injury or death
Effective Dose
- The amount of a drug, or dose, that produces a desired effect
- A dose can be called effective only if the amount of the test drug causes a defined effect in 50% of the animals that receive it (ED50)
Lethal Dose
The dose of a test drug that kills 50% of the animals that receive it (LD50)
Therapeutic Index (Margin of Safety)
- The drug dosage or dose that produces the desired effect with minimal or no signs of toxicity
- This value is determined by comparing the drug's LD50 and ED50
- The wider this therapeutic index or margin of safety is, the better
Drugs are named and marketed under two names:
- Generic name
- Brand name
Generic Name
Sometimes written using lowercase letters, and it is the same in all countries
Brand Name (proprietary, trade)
- Establishes legal proprietary recognition for the corporation that developed the drug
- Usually written in capital letters or begins with a capital letter
- It may also have the superscript R of the symbol (r) which means "registered"
- Brand names are
Drug labels must included the following:
- Drug name (generic and trade)
- Drug concentration
- Drug quantity
- Name/address of the manufacturer
- Lot number and expiration date
- Withdrawal time
- Controlled substance status
Compounding
- The preparation, mixing, assembling, packaging, and/or labeling of a drug based on an order from a licensed practitioner to an individual patient
- Example: flavoring, dosing for specific weights, turning pills into a liquid
- Caution: human error in ca
Package inserts provide the following info:
- Registered trade name/generic name
- Description or composition statement
- Clinical pharmacology (mode of action)
- Indications and usage
- Contraindications
- Precautions
- Warnings
- Adverse reactions or side effects
- Over dosage
- Dosage and admini
Dispensing vs. Prescribing
- If an animal requires a drug, the veterinarian can either write a prescription to be filled at a human pharmacy, or dispense the drug from the veterinary clinic
Prescription
An order to a pharmacists, written by a licensed veterinarian, to prepare the prescribed medicine, to affix directions and to sell the drug to the client
Seven parts of a written prescription:
1. The veterinarian's name, address, and telephone number
2. Client's name and address, species, and name of the patient
3. The name of the drug, the strength of the drug, and the quantity to be given to the patient
4. The instructions for giving the drug
Label on the prescription bottle must have:
- Name and address of the dispenser
- Client's name
- Animal's name & species
- Drug name, strength, & quantity to be given
- Date of the order
- Directions for use
- Refill information
Therapeutic Index (TI) Calculation
You can calculate the TI by dividing the LD50 by the ED50
Drug X has an LD50 of 100 mg/kg and an ED50 of 2 mg/kg
LD50/ED50 = 100 mg/kg / 2 mg/kg = 50 TI