ATI RN
Chapter 26 principles of pharmacology Questions
Question 1 of 5
Phenylephrine causes
Correct Answer: A
Rationale: Phenylephrine causes constriction of vessels in the nasal mucosa (A), an alpha-1 agonist shrinking mucosal blood vessels, reducing congestion (e.g., in decongestants). It doesn't increase gastric secretion/motility (B), a cholinergic effect. It decreases skin temperature (C is incorrect) by vasoconstriction. It causes mydriasis (D is incorrect), not miosis, via pupil dilation. Option E (original) is false. This selective alpha-adrenergic action underlies its topical/systemic use, with minimal beta effects, though reflex bradycardia or hypertension may occur, requiring cautious use in cardiovascular patients.
Question 2 of 5
Vanishing cream is an ointment that may be classified as
Correct Answer: D
Rationale: Vanishing cream is an emulsion base (D), typically oil-in-water (o/w), disappearing on skin application as water evaporates, leaving a non-greasy film (e.g., cosmetic creams). Water-soluble bases (A) dissolve in water (e.g., PEG ointments), oleaginous bases (B) are greasy (e.g., petrolatum), and absorption bases (C) absorb water (e.g., lanolin). Option E (original) is invalid. This o/w emulsion enhances drug delivery (e.g., hydrocortisone) and patient compliance due to its aesthetic appeal, contrasting with greasy bases in topical formulations.
Question 3 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 4 of 5
Match the drug product below with the type of controlled-release dosage form that it represents
Correct Answer: A
Rationale: A matrix device (A) matches Biphenamine Capsules (1), where drug release occurs via diffusion through an inert matrix (e.g., wax). Ion-exchange (B) fits Thorazine Spansule (2), releasing via resin binding. Hydrocolloid (C) suits Valrelease (3), swelling to control release. Osmotic system (D) matches Slow-K (4), using osmotic pressure. Coated granules (original E) are distinct. Matrix systems provide sustained release, balancing simplicity and efficacy, widely used for chronic conditions, minimizing peak-trough fluctuations.
Question 5 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.