Drug Efficacy

Question 1

clinical trails

Answer 1

controlled studies to assess dosage, administration, safety and efficacy of a drug

Question 2

phase 1 of a clinical trial

Answer 2

small scale (<100) that tests pharmacokinetics (tolerable dosing range, bioavailability, excretion)

Question 3

phase 2 of a clinical trial

Answer 3

medium scale (>100) testing for efficacy, monitoring safety in greater #

Question 4

phase 3 of a clinical trial

Answer 4

large scale, randomized, double-blinded, compare against placebo or current accepted treatment

Question 5

how is safety or efficacy studied/surveilled after approval? (2)

Answer 5

systematic reviews, meta-analysis (combines data from multiple trials)

Question 6

how is data from results of meta-analyses displayed?

Answer 6

in forest plots

Question 7

what do forest plots provide data on? (3)

Answer 7

of trials, outcomes of trials, size of trials (overall summary of all trials)

Question 8

What is the OR (odds ratio)?

Answer 8

ratio of event rate in treatment group / control group

Question 9

what is the therapeutic index (TI)?

Answer 9

ratio of median toxic dose and effective dose

Question 10

what is TI equal to?

Answer 10

TI = TD50 / ED50

Question 11

what is used to describe effect or toxicity in patient trials?

Answer 11

quantal dose response curve

Question 12

what is ED50?

Answer 12

effective dose (conc. where 50% patients exhibit beneficial response to drug)

Question 13

what is TD50?

Answer 13

toxic dose (conc. where 50% patients exhibit adverse response to drug)

Question 14

what does a quantal dose-response curve show?

Answer 14

cumulative # of patients who have predefined response to drug (% individuals vs dose)

Question 15

is it better to have a larger or smaller TI and why?

Answer 15

larger, drug is tolerated with minimal toxicity and gives dosing flexibility

Question 16

what is an issue with quantal dose-response curves?

Answer 16

individuals have variabilities in their conditions and response to drug

Question 17

what is Relative Risk Reduction =?

Answer 17

1 - (event rate in treatment group / control group)

Question 18

why can RRR by misleading?

Answer 18

doesn’t convey magnitude of baseline risk (small reduction in smth infrequent = big reduction in smth very frequent)

Question 19

what is Absolute Risk Reduction =?

Answer 19

event rate in control - event rate in treatment group

Question 20

what is the ARR?

Answer 20

(Absolute Risk Reduction) absolute # of cases prevented by taking a drug

Question 21

what does NNT stand for?

Answer 21

Number needed to treat

Question 22

What is NNT?

Answer 22

of patients needed to take drug for 1 to benefit

Question 23

what does NNT =?

Answer 23

1 / ARR (abs. risk red.)

Question 24

is a low or high NNT good?

Answer 24

low (less ppl need to take drug for 1 to benefit, NNT = 1 best)

Question 25

what is NNH?

Answer 25

Number needed to harm (higher is better)

Question 26

if ARR is negative, what is 1 / ARR =?

Answer 26

NNH