Adverse Drug Effects & Toxicology Flashcards
(39 cards)
What is a graded dose response curve?
Measures response of increased dose given to an individual on a continuous scale
What is a quantal response curve?
Characterize all-or-nothing pharmacologic response
What are the midpoints that the therapeutic index compares?
Midpoints: ED50 and LD50
Therapeutic index = ?
TI=LD50/ED50
What does the therapeutic index measure?
Factor, by which the effective dose for 50% of the population must be increased to cause negative side effect in 50% of the population
Does a high therapeutic index correlated with a more dangerous or safe drugs?
Safe
What does the standard safety margin compare?
Extremes ED99 and LD1
SSM = ?
[(LD1/ED99)-1]*100
What does the standard safety margin measure?
The percent by which effective dose in 99% of the population must be increased to cause negative side effect in 1% of the population
What are extension effects?
Arise from therapeutic effect, they are dose related and predictable
What are side effects?
Unrelated to the therapeutic goal, they are predictable and dose dependent
What is the difference between adverse drug reactions and toxic reactions?
Adverse drug reactions occur at usual therapeutic doses, toxic reactions occur outside therapeutic range
What is an idiosyncratic reaction?
Genetically determined, abnormal and unpredictable response to drug
What are the possible pharmacologic consequences of drug drug interactions?
Enhancement or antagonism of drug via the same target
What are the possible physiologic consequences of drug drug interactions?
Enhancement or antagonism of drug via distinct effector system
What patients are at high risk for drug drug interactions?
Elderly, high risk clinical situations, renal/hepatic disease, multiple prescribing physicians
Drug drug interactions may influence gastric motility. If there is a decrease in motility by drug B, what is the effect on drug A?
Drug A will have a lower peak plasma concentration and decreased absorption rate
If drug B is given after drug A and changes the pH so that drug A can not be absorbed, what is the effect on the bioavailability of drug A.
Reduced bioavailability
Drug B is given after Drug A. Drug B decreases cardiac output. What is the effect on Drug A?
Increased plasma levels due to decreased hepatic clearance
Clinically, what is the most significant consequence of drug-drug interactions?
Changes in metabolic processing of drug (inducers/inhibitors)
Does Rifampin induce or inhibit drug metabolism?
Induce
Do erythromycin and azole antifungals induce or inhibit drug metabolism?
Inhibit
Is phenobarbital an inducer or inhibitor of drug metabolism?
Phenobarbital
What is the single most important determinant of poising outcomes?
Provision of good supportive care
