ATI RN
Chapter 12 principles of pharmacology Questions
Question 1 of 5
The following are substrates for CYP3A:
Correct Answer: A
Rationale: Ciclosporin (A) is a CYP3A substrate, metabolized in the liver, affecting its immunosuppressive levels (e.g., transplant therapy). Clarithromycin (B) is too, also correct but A is chosen. Phenytoin (C) uses CYP2C9. Adrenaline (D) is COMT/MAO-metabolized. Warfarin (original E) is CYP2C9. CYP3A's broad substrate range, critical in drug interactions (e.g., with grapefruit juice), shapes ciclosporin's pharmacokinetics, necessitating monitoring.
Question 2 of 5
Important factor/s which may govern diffusion of drugs across cell membranes
Correct Answer: D
Rationale: Diffusion across membranes depends on pKa (ionization state), pH (proportion of non-ionized form via Henderson-Hasselbalch), and lipid solubility (membrane permeability). Molecular weight also influences diffusion but isn't listed. A, B, and C are individually correct, but D (‘All of the above') is the most complete answer, encompassing all key factors. This reflects how physicochemical properties dictate drug movement, critical for pharmacokinetics and drug design.
Question 3 of 5
Lipophilicity reduces
Correct Answer: D
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.
Question 4 of 5
In which organ is the majority of cytochrome P450s most highly expressed?
Correct Answer: B
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.
Question 5 of 5
Which of the following is a True statement?
Correct Answer: C
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.