ATI RN
Chapter 26 principles of pharmacology Questions
Question 1 of 5
The shells of soft gelatin capsules may be made elastic or plastic-like by the addition of
Correct Answer: A
Rationale: Sorbitol (A) makes soft gelatin capsule shells elastic or plastic-like, a polyol plasticizer softening the gelatin matrix, enhancing flexibility (e.g., vitamin D capsules). Povidone (B) is a binder, not a plasticizer here. Polyethylene glycol (C) can plasticize but is less common. Lactose (D) is a filler, not elasticizing. pKa (original E) is irrelevant. Sorbitol's hygroscopicity maintains shell integrity, improving handling and patient acceptability in liquid-filled capsules, a key formulation advantage.
Question 2 of 5
The rate of drug bioavailability is most rapid when the drug is formulated as a
Correct Answer: D
Rationale: A solution (D) offers the most rapid bioavailability rate, as the drug is pre-dissolved, bypassing disintegration and dissolution (e.g., oral syrups absorbed in minutes). Controlled-release (A) delays release. Hard gelatin capsules (B) and tablets (C) require disintegration. Suspension (original E) is fast but slower than solutions. This immediacy maximizes absorption speed, ideal for acute conditions, though solutions may face stability or palatability challenges in formulation.
Question 3 of 5
All of the following statements about plasma protein binding of a drug are true except
Correct Answer: D
Rationale: Option D is false; drugs highly bound to plasma proteins (e.g., warfarin) have a smaller V_D, as they stay in plasma, unlike tissue-bound drugs (e.g., digoxin, large V_D). Displacement increases V_D transiently (A), boosts free drug for filtration (B), and risks toxicity in highly bound drugs (C), all true. Option E (original) is replaced. Protein binding restricts distribution, reducing V_D, a key pharmacokinetic factor affecting free drug levels and potential interactions, critical in polypharmacy.
Question 4 of 5
Monomer units of proteins are known as
Correct Answer: C
Rationale: Amino acids (C) are the monomer units of proteins, linked by peptide bonds (e.g., glycine in collagen), forming polypeptides via translation. Monosaccharides (A) build carbohydrates. Prosthetic groups (B) are non-protein enzyme parts. Purines (D) and nucleosides (original E) relate to nucleic acids. This biochemical foundation underpins protein drugs (e.g., insulin), where sequence dictates function, essential in pharmacology for therapeutic protein design and metabolism studies.
Question 5 of 5
N-oxidation will be involved with the metabolism of following drugs, except
Correct Answer: C
Rationale: Phenytoin (C) does not undergo N-oxidation; it's metabolized via CYP2C9 hydroxylation to HPPH, unlike dapsone (A), meperidine (B), and chlorpheniramine (D), which form N-oxides via flavin monooxygenases or CYP450. No original E. N-oxidation, a phase I reaction, adds oxygen to nitrogen, increasing polarity (e.g., meperidine to normeperidine), but phenytoin's aromatic ring hydroxylation differs, impacting its nonlinear kinetics and therapeutic monitoring, distinct in drug metabolism pathways.