Lec 51:Pharmacology Principles Flashcards
Pharmacodynamics
What the drug does to the body
Pharmacokinetics
What the body does to the drug such as metabolism and elimination
Bioavailability
Proportion of an administered dose of a drug usually orally, that enters circulation
What information do we need to know about a drug before it can be safely and effectively used?
- Dose Dependent Relationship
- Mechanism of Action
- Clinical Pharmacology (safety, efficacy)
Steps to development/approval of a drug prior to use in the clinic:
- Drug Screening - Assays modeling disease states, a rational drug design
- Preclinical Pharmacology - Lab studies to determine toxicity and biologic activity
- Proof of concept and initial safety tests
Phases of testing a drug
Phase I - Check toxicity of drug and plot on a dose dependent curve
Phase II - Demonstrate that safe doses give therapeutic effect
Phase III - Compare with placebo or standard in a large group
Phase IV - Careful post-marketing surveillance
TD50?
Dose that gives 50% of the population a toxic effect
LD50?
Dose at which 50% animals are dead
ED50?
Dose needed to give 50% maximal effect
Therapeutic Index?
TI = TD50/ED50 or LD50/ED50
Higher TI means
Safer
What kind of mechanism do diuretics and laxatives follow?
Osmotic actions so physiochemical mechanisms
What do antacids, chelating agents, and disinfectants all have in common?
Don’t use receptors to get drugs to work, just chemical reactivity