QuestionSBA
QuestionChoice
LD50 and TD50 are different terms which measure therapeutic indexes. LD50 measures the lethal dose. This is a dose that produces a lethal response in 50% of animals. TD50 is the toxic dose which measures at which dose do 50% of animals have a damage-inducing response. These terms are not interchangeable.
10004929
d
LD50 and TD50 are interchangeable terms used to measure therapeutic indexes
QuestionChoice
This statement is clearly untrue. There are many instances where partial agonists are useful drugs such as varenicline which is a partial agonist of morphine and pholcodine which is a partial agonist of nicotine. Although partial agonists do not produce the maximum available response, they are much safer drugs to administer.
10004930
e
It is always better to give full agonist drugs, rather than partial agonist drugs if they are available
QuestionChoice
EC50 ('effective concentration, 50%') is a number which quantifies a drug's potency. The more potent, the lower the EC50 as it requires less of the drug is required to achieve 50% of the maximum possible response.

An easier way to think of it is that a higher EC50 means that the drug works 'less well', and thus more of it is required to have an effect.
10004926
a
The concentration that produces 50% of the maximum response is called EC50
QuestionChoice
This is untrue, as different drugs have different EC50 values, and as such have different effects at different concentrations. Effectively, different drugs have different potencies.
10004927
b
All drug agonists produce the same maximum effect
QuestionChoice
A partial agonist would be less potent, and thus would have a higher EC50. A higher dose of the drug would be required to achieve 50% of the maximum effect possible.
10004928
c
A partial agonist has a lower EC50 compared to a full agonist
Concept
Chapter
2693
4347
General Pharmacological Concepts
Topic
195
Pharmacology
13532
A medical student is reading about the foundations of various general pharmacological concepts.

Which of the following options is correct?
a