Exposures

Question 1

When would a parallel group design not be suitable?

Answer 1

• In rare diseases in which the population is very small

- A fast-moving disease

Question 2

What is a single arm trial?

Give an example

Answer 2

Participants are enrolled and receive the intervention.
Single arm trials should only be used when a placebo isn’t justified or ethical.
In oncology phase 1 trials (when all treatment options have been exhausted and placebo isn’t justifiable)

Question 3

What is a historical/external control?

When could this possible be used?

Answer 3

Compares data to ones obtained from patients in previous studies:
registry, natural history study, completed clinical trials.

Could be used for rare diseases when no approved therapy exists

Question 4

Which PK parameters determine a dosing regimen?

Answer 4

Clearance (Cl)
Volume of distribution (Vd)
Half-life (t1/2)
Bioavailability

Question 5

Examples of PK studies and its outcomes

Answer 5

Single dose studies
Repeat dose studies

Outcome: descriptive and conceptual PK parameters in humans.

Question 6

What is clearance (CL)?

Answer 6

the volume of blood cleared of drug per unit time (L/hr or ml/min)

Question 7

Is clearance a constant?

Answer 7

Clearance by an organ occurs at a constant rate determined by organ function and blood flow.

Clearance is only a constant if the elimination process is not saturated.

Question 8

why is clearance important in drug dosing?

Answer 8

Cl determines maintenance dose rate to achieve a target plasma concentration at steady state.

Question 9

How many half-lines does it take for a drug to reach steady state/complete elimination?

Answer 9

Five t1/2

is also the time taken to completely eliminate drugs from the body