Chapter 02: Principles of Pharmacology
Moscou: Pharmacology for Pharmacy Technicians, 3rd Edition
1. The pharmacokinetic phases control the _____ of the drug’s effect and the _____ of the drug
a. intensity, duration
b. duration, effect
c. mechanism, safety
d. length, efficacy
As a drug moves throughout the body, it undergoes changes that may increase or decrease its
absorption, distribution, metabolism, or elimination. These pharmacokinetic phases control
the intensity (how much is absorbed and therefore distributed) of the drug’s effect and the
duration (how fast it is metabolized and eliminated) of the drug action.
DIF: Cognitive level 2: Comprehension REF: p. p0215 OBJ: 2
2. The time it takes for a drug to reach the concentration necessary to produce a therapeutic
effect is called the _____ of action.
The length of time it takes for drug action to begin after a dose is administered is called the
onset of action. The onset of action is not achieved until the drug reaches the minimum
concentration in the body needed to produce drug action. The duration of action is the time
between the onset of action and discontinuation of drug action. The duration of action is the
amount of time (length/time) the drug concentration remains within the therapeutic range. The
mechanism of action refers to the specific biochemical interaction through which a drug
substance produces its pharmacological effect, the time in which it produces the effect.
DIF: Cognitive level 1: Recall REF: p. p0225 OBJ: 8
3. Duration of action is the time between the _____ of action and _____ of drug action.
a. mechanism, duration
b. onset, discontinuation
c. duration, concentration
d. onset, mechanism