Compartment Models — MCQs

Volume of distribution of a drug is 500 ml and target concentration of drug in blood is 5 g/L. 20% of administered drug is reached to systemic circulation. What will be the loading dose of that drug -

A 70 kg man was given a drug with a dose of 100 mg/kg body weight, twice daily. The half-life (t1/2) is 10 hours, the plasma concentration is 1.9 mg/mL, and the clearance is unknown. What is the clearance of this drug?

What would happen to the half-life and plasma concentration of a drug which follows first-order kinetics, if the dose is doubled?

Low apparent volume of distribution of drug indicates that:

What is the commonly used concentration of tetracaine for topical anesthesia in minor ophthalmic procedures?

In which of the following conditions is digoxin most likely to accumulate to toxic levels?

What is the preferred concentration range of lidocaine for topical anesthesia?

The following plot comparing pharmacokinetics of different ibuprofen brands is called:

A pharmacology researcher is studying the interaction of a new drug with a receptor system. Two candidate antagonist compounds (Drug X and Drug Y) are tested against a standard agonist at increasing concentrations. The resulting dose-response curves are plotted (Image 1). In the graph, the X-axis represents Log [Agonist Concentration (mol/L)] and the Y-axis represents % Maximum Response (0–100%). Three labeled sigmoid curves are shown: (1) 'Control' — the agonist alone, reaching 100% Emax; (2) 'Drug X + Agonist' — a parallel rightward shift of the control curve with unchanged Emax (~100%); (3) 'Drug Y + Agonist' — a rightward shift with a clearly depressed/lowered Emax (~50–60%). Based on the curves, which of the following statements best describes the mechanism of Drug Y?

Zero order kinetics is followed by all of the following drugs EXCEPT?