Dose Response curve Quiz

In the following graded dose-response curve, which statement about parameter (Q) is true?

• It measures the maximum response

• It is inversely related to potency

• It represents the dose producing 100% of Emax

• It measures drug bioavailability

The graph below compares four antihypertensives (A, B, C, D). Which drug has the highest efficacy but lowest potency?

• Drug D (Emax = 80 %, EC50 = 1e-7 M)

• Drug A (Emax = 60%, EC50 = 1e-9 M)

• Drug C (Emax = 95%, EC50 = 1e-5 M)

• Drug B (Emax = 95%, EC50 = 1e-8 M)

A dose-response curve for Drug A (Emax = 80%) overlaps completely with its curve after Drug B. What does this imply?

• Drug B is a non-competitive antagonist

• Drug B has no effect on Drug A receptors

• Drug A receptors are saturated

• Drug B increases Drug A ’s potency

Which of the following characteristics differentiates competitive from non-competitive antagonists?

• Changes in EC50 only

• Decrease in Emax only

• Both Emax and EC50 remain constant

• Competitive antagonists increase EC50 without affecting Emax

In an experiment, adding A drug to an agonist reduces Emax by 40% but does not alter EC50. Which graph best represents this interaction?

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This image shows two log dose-response curves of drug (1) alone (blue color), after drug (2) (red color). Which of the following statements about these drugs is TRUE?color) and

• Drug (1) couldn’t achieve the same maximal efficacy before and after drug (2)

• More concentrations were required for drug (1) to achieve the same maximal efficacy after drug (2)

• Drug (1) achieves higher maximal efficacy after drug (2)

• The potency of drug (1) was increased after drug (2)

On a semilog dose-response curve, EC50 is determined from:

• The Y-axis at 50% of Emax

• The X-axis at 50% of Emax

• The linear portion of the sigmoid curve

• The steepest slope of the curve

From the following graded dose response curve, the EC50 of drug A after drug B (the red curve) is:

• from 5e-7 – 2e-6

• from 1e-7 -- 4e-7

• from 5e-5 -- 5e-4

• from 5e-8 -- 9e-8