General Principles Flashcards
Refers to the amount of drug that reaches the systemic circulation.
Bioavailability
Used to determine the safety and efficacy of generic drugs.
Bioequivalence
Measures the dosage or concentration required to bring about 50% of the drug’s maximal effect.
Potency / EC50
Dose at which 50% of the individuals exhibit the specified quantal effect.
ED50 / Median Effective Dose
Dose at which 50% of the animals manifest a particular toxic effect.
TD50 / Median Toxic Dose
Transfer of drug from site of administration to bloodstream.
Absorption
Refers to the apparent volume into which drug is able to distribute.
Volume of distribution
Elimination of drug at a constant rate.
Zero order kinetics
Elimination at a rate that is proportional to the serum concentration of the drug.
First order kinetics
Addition of polar moiety (sulfate, acetate, or glucoronate)
Phase II metabolism
Use of CYP 450 system, oxidation, reduction, or hydrolysis.
Phase I metabolism
Describes the rate at which a specific drug is cleared from the system.
Clearance
Refers to the amount of time required for the amount of drug in the body to decrease to half of its value after administration of the drug has been stopped.
Half life (t 1/2)
Defined as the single amount of drug that is needed to achieve a desired plasma concentration quickly.
Loading dose
Amount of drugs must be given overtime in order to maintain desired plasma concentration
Maintenance dose
Used as a measure of drugs safety.
Therapeutic index