Drug Rules and Dosing Flashcards
Pharmacology
The study of how drugs work in the body
Clinical pharmacology (therapeutics)
The study of how drugs are specifically applied to clinical conditions (the applications of pharmacology)
Mechanism of action
How a drug alters normal physiology (negative and positive side effects)
Physiological changes
Alter patient’s clinical parameters
Adverse effects
Alter behaviors of the patient (i.e. vomiting)
Rule #1 for safe drug usage
All drugs are poisons (it’s often how much you give and how it is administered that has the potential to save a life or take a life)
Rule #2 for safe drug usage
All doses are guesses (a dose is an estimation of what amount of drug should produce the beneficial effect on average for a population of animals; have to take into account the variations in the individual patient’s physiology; most dosages are based on anecdotal evidence)
Rule #3 for safe drug usage
No drug is a silver bullet (no drug completely eradicates a disease; all drugs produce positive or negative side effects, must weigh the benefits and risks)
Rule #4 for safe drug usage
Complacency kills (once you get comfortable with a drug, risk of forgetting rules 1-3; need to be vigilant and check for early signs of adverse effects)
Chemical name
- Name given to drug when first discovered
- Assigned by the Chemical Analysis Society
- ID the atomic or molecular structure
- Found on package insert
Non-proprietary name
- “Generic” name or active ingredient
- Assigned by United States Adopted Names council (not owned by one company)
- Usually written in lower case
- Name includes prefix (IDs the individual drug within a group) and stem (IDs the drug group)
Proprietary name
- Brand (or trademark) name
- Name developed by the company that is requesting approval for the drug from the FDA (IDs property of that company)
- Drugs are marked under the brand name while under patent protection. Once the patent expires, the company can market its product either as the generic name or the brand name
Generic equivalent drugs
- Must be approved by FDA
- “Identical” requirement is a legal term, not necessarily realistic (to be identical, the drug has to be 80-125% bioequivalent to the original drug)
Bioequivalent
An equivalent amount of generic drug must be absorbed and delivered to the target site in the body compared to the original brand or parent drug; must include the identical amount of the active ingredient
Generic equivalents in food animals
- The amount of the drug residue left after the withdrawal time can be no more than the original patent drug
- May have other chemicals added to enhance absorption - but must still have the same bioequivalence of 80-125% with no greater residue left
Residue
Amount of drug left in the meat, eggs, or milk
Withdrawal time
The amount of time from the last dose of the drug until the animal can be harvested for human food or its products (eggs, milk) used for human food
Extract
- Drugs that are prepared from plant or animal parts
- Regulated by the FDA (under dietary supplements and food)
- Generally less expensive
- May be variability from batch to batch on the active ingredient (but still needs to be within the bioequivalent range)
Nutraceutical
- Natural, bioactive chemical compound; includes vitamins, minerals, and herbal supplements
- Regulated by the FDA (under dietary supplements and food)
Legend Drugs
- Medications that require prescriptions or must be ordered in-house by the clinician
- Identifiable by Rx symbol or a legend (caution describing federal law restriction)
- Cannot be dispensed without a valid Veterinarian-Client-Patient-Relationship (VCPR) (vet has examined the patient or has adequate knowledge of the patient, and has agreed to assume responsibility for veterinary care)
The Green Book
Lists all FDA approved drugs and generics both OTC and legend drugs
Over the counter (OTC)
- No Rx, legend, or restrictive language on the packaging
- Either has a very safe ingredient or a much lower amount of a prescription ingredient
- Manufacturer will not release the drug if it is not idiot proof (for liability reasons)
United States Pharmacopiea (USP)
- Non-governmental organization that sets the standards for purity and quality of drug manufacturing for drugs to be marketed in the US
- Raw drug materials produced outside the US must be manufactured to USP standards or else drug companies in the US cannot use them in their drugs
- Inability of foreign raw drug manufacturers to meet USP standards can result in US drug manufacturer being unable to produce the drug - get temporary shortages
Package insert
- Contains brand name (and generic name)
- Strength of the medication
- IDs as legend drug
- Physical description of drug form
- Chemical name
- Indications (will not describe off label use)
- FDA approved dosage and administration
- Dosage regimen
- Adverse drug reactions
- Side effects
- Info for owners
- Warnings and precautions
- Black boxed warning
- Clinical pharmacology
- Safety and effectiveness
- Storage conditions
- How the medication is supplied
Dosage
How to determine the amount of drug that has been approved to be given to any animal
Dose
- The mass of drug given to a single patient (calculated)
- Should not be listed as a volume amount or as a number of dose forms