Veterinary Pharmacology

• Origins of veterinary pharmacology date back to the early 1700s in Europe
• Materia medica is the study of the physical and chemical characteristics of materials used as medicine
• Scientists extracted and synthesized drugs from plant components, bacteria, and animal sources
• Most drugs today are made synthetically in laboratories
• Pharmaco means drug
• Pharmacology is the study of drugs
• Therapy means treatment of disease
• Pharmacotherapy is the treatment of disease with medicines
• Kinetics is the scientific study of motion
• Pharmacokinetics is the study of drug motion, which includes absorption, blood levels, distribution, metabolism, and excretion of drugs
• Bioavailability is the quantity of drug available for use by the target tissue
• Metabolism is the enzymatic breakdown of a drug making it ready for elimination by the body
• Excretion is the process by which a drug is eliminated from the body via kidney, respiratory
• Chemical name is the exact designation of the chemical structure of a drug as determined by rules of accepted systems of chemical nomenclature
• Generic name is an official name given to a drug and it is licensed under this name. All manufacturers of the drug list it by its generic name
• Trade name is a name assigned to a product by its manufacturer (registered or not registered) for identification
• Effective dose is the amount of the test drug that causes a defined effect in 50% of the animals that receive it
• Lethal dose is the amount of the test drug that kills 50% of the animals that receive it
• Therapeutic index is the drug dosage or dose that produces the desired effect with minimal or no signs of toxicity
• LD 50 / ED 50
• Prescription drugs are regulated by authorities like FDA and Pharmacy Board of Trinidad and Tobago
• Prescription drugs are limited to use under the supervision of a veterinarian or physician due to potential danger, toxicity concerns, administration difficulty, or other considerations
• Prescription drugs are prescribed to animals once a veterinarian/client/patient relationship has been established
• Extra-label drugs are drugs used in a manner that is not specifically described on the FDA-approved label
• Extra-label drug use is allowed under the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA)
• Over-the-counter drugs (OTC drugs) do not have a significant potential for toxicity and do not require special administration
• Controlled substances are drugs considered dangerous because of their potential for human abuse or misuse
• Controlled substances must be registered annually with the DEA by veterinarians who use or prescribe them
• Authorized handlers of controlled substances must keep records of orders, receipts, uses, discards, and thefts of controlled substances for two years following each transaction
• New veterinary drugs must go through a series of tests by regulatory bodies like FDA, European Medicines Agency, and Medicine Control Center
• There are four major steps in drug development: Synthesis/discovery of a new drug compound, Safety/effectiveness evaluation, Submission and review of the New Animal Drug Application (NADA), Postmarketing surveillance stage
• Injectable routes of administration include IV, IM, and SQ
• Drugs given IV have rapid onset of action, higher initial body levels of drug, and shorter duration of activity
• Drugs given IM have relatively rapid onset of action and longer duration of activity than IV drugs
• Drugs given SQ have slower onset of action and longer duration of activity than IV and IM drugs
• Inhalation administration introduces drug to the animal by having it breathe the drug into the lungs
• Oral administration delivers the drug directly to the animal’s gastrointestinal tract
• The dose of a drug is the amount of drug administered at one time to achieve the desired effect
• Loading dose is the initial dose of drug given to get the drug concentration up to the therapeutic range in a very short period of time
• Maintenance dose is the dose of drug that maintains or keeps the drug in the therapeutic range