Lec2 Flashcards
What are the 4 major steps in drug development?
- Synthesis/discovery of a new drug,
- Safety/ effectiveness evaluation,
- Submission and review of the new animal drug application (NADA),
- Postmarketing surveillance
Preliminary Studies
determine if the drug produces the intended effect and if toxic side effects are produced
Preclinical studies
If preliminary studies produce satisfactory results and determine safety and effectiveness; Includes short and long term toxicity studies
Also includes special tests such as immediate drug reactions, organ system damage, reproductive effects, carcinogenicity, and teratogenicity
Investigational New Animal Drug Application (INAD)
is submitted to the FDA upon sufficient animal data to demonstrate safety and effectiveness
The FDA reviews the INAD application and responds within 30 days
Target species
(species intended for use) clinical trials are then conducted to determine safety, toxic/adverse side effects
Studies on shelf life and drug stability are also conducted
New Animal Drug Application (NADA)
filed with the FDA subsequent to satisfactory clinical trials
Approval and license for manufacture are granted
The company and FDA monitor the drug as long as it is manufactured
Drugs intended for use in food - producing animals must also be tested for consumer safety and be free of drug residues
Drug Toxicity Evaluation
Drugs must also be tested to determine if they cause toxic side effects
Need to know the dose at which organ/tissue damage occurs, that may if dose is high enough result in permanent injury or death
Must also determine the dose of drug that produces desired effect
Effective Dose - 50 (ED 50)
the dose of test drug that produces a desired effect in 50 percent of the animals tested
Lethal Dose - 50 (LD 50)
dose of test drug that kills 50 percent of the animals tested
Therapeutic Index (TI)
the relationship between a drug’s ability to achieve the desired effect compared with its tendency to produce toxic/lethal effects or “margin of safety.” It is the drug dosage or dose that produces the desired effect with minimal or no signs of toxicity. = LD50/ED50
Is a Safer TI a high or low number?
It is desirable to have a TI greater than 1 since the larger the number of the TI, the greater the margin of safety and the lower the TI number, the narrower the margin of safety thus greater caution must be used with the medication!
Systems-oriented screen
tests the drug’s effect on particular organ systems
Done after toxicity tests
Typically includes cardiovascular, respiratory, muscular, nervous and endocrine systems
Long-term toxicity tests
(chronic studies)
Study toxic effects after repeated dosing over long periods of time
Direct (Drug) Marketing
drugs purchased directly from the manufacturer
(Drug) Distributors
(wholesalers) – companies that purchase drugs from the manufacturer and resell to veterinarians
