Pharma Flashcards
What is the purpose of a concentration-response curve?
It illustrates the relationship between the drug concentration and the magnitude of its effect, helping to assess drug potency and efficacy.
How is potency represented in a concentration-response curve?
Potency is indicated by the position of the curve along the x-axis. A drug with lower EC50 or ED50 is more potent.
What does the height of the curve indicate?
The height of the curve indicates the drug’s efficacy, which is the maximum effect a drug can produce.
How can the time to 50% improvement be interpreted from the curve?
It provides a measure of how fast a drug works, allowing comparisons of onset of action betwqeen drugs.
How can a concentration-response curve help compare drugs?
It allows comparison of drugs based on their potency (EC50) and efficacy (height of the curve).
What information can be derived from a graded dose-response curve?
Key information includes maximal effect (Emax), potency (EC50), and the relative potency and efficacy of drugs.
What is a quantal dose-response curve?
It shows the response to a drug in a population, represented as all-or-none data (e.g., the percentage of individuals who achieve a defined effect).
What are ED50, TD50, and LD50 in quantal dose-response curves?
- ED50: Dose effective in 50% of the population.
- TD50: Dose toxic to 50% of the population.
- LD50: Dose lethal to 50% of the population.
What does a narrow therapeutic index indicate in a quantal dose-response curve?
It indicates a smaller safety margin, meaning the effective dose is close to the toxic dose.
How are potency and efficacy different?
Potency refers to the concentration of a drug needed to produce a specific effect, while efficacy is the maximum effect the drug can achieve.
Can a drug with lower potency still be effective?
Yes, a drug with lower potency can be effective if its efficacy is high enough to achieve the desired therapeutic effect.
What determines the relative potency of drugs?
Relative potency is determined by comparing the EC50 or ED50 values of drugs that produce the same effect.
What does it mean if two drugs have similar efficacy but different potency?
Both drugs can achieve the same maximum effect, but the more potent drug requires a lower concentration to do so.
Can a drug with lower potency still be clinically useful?
Yes, as long as its efficacy is sufficient to achieve therapeutic goals.
What is the therapeutic index (TI)?
TI is the ratio of TD50 to ED50, used to evaluate drug safety. A higher TI indicates a safer drug.
