The Joint Commission recommends which of the following abbreviations for the “Do Not Use” list?

Correct Answer: A

Rationale: The correct answer is A: qd. The abbreviation "qd" is listed in the Joint Commission's "Do Not Use" list because it can be misinterpreted as "qd" (every day) or "qd" (every other day). This ambiguity can lead to dosing errors. Choice B: NPO is not recommended for the "Do Not Use" list by the Joint Commission. Choice C: Subling is not an abbreviation commonly associated with dosing instructions. Choice D: bid is a standard abbreviation for "twice a day" and is not on the "Do Not Use" list.

Correct Answer: C

Rationale: Cephalosporins inhibit the synthesis of the bacterial cell wall by binding to penicillin-binding proteins (PBPs), disrupting cell wall formation. They are beta-lactam antibiotics, similar to penicillins. Macrolides (A) inhibit bacterial protein synthesis, aminoglycosides (B) interfere with protein synthesis, and tetracyclines (D) inhibit protein synthesis by binding to the bacterial ribosome.

Correct Answer: C

Rationale: The correct answer is C: Weakly acidic drugs. In basic urine (pH > 7), weakly acidic drugs will be more ionized and therefore less reabsorbed in the renal tubules, leading to faster excretion. Weakly basic drugs (A) will be more unionized in basic urine and reabsorbed. Lipid-soluble drugs (B) are typically reabsorbed regardless of urine pH. Protein-conjugated substances (D) are usually metabolized before excretion, so urine pH has minimal impact on their excretion rate.

Correct Answer: A

Rationale: Passive diffusion involves movement of drug molecules across the cell membrane lipid layer from an area of high concentration to low concentration, without the need for energy or carrier proteins. Lipid-soluble drugs can easily diffuse through the lipid bilayer due to their hydrophobic nature. This process is driven by the concentration gradient and follows Fick's law of diffusion. Ion channels (B) facilitate the movement of ions, not drugs. Methyl residues (C) and transport proteins (D) are not directly involved in passive diffusion of drugs.

Correct Answer: A

Rationale: The correct answer is A: Amphetamine. Beta-blockers like Propranolol, Carvedilol, and Timolol work by blocking the effects of adrenaline on beta receptors, reducing heart rate and blood pressure. Amphetamine, on the other hand, is a stimulant drug that works by increasing the release of neurotransmitters like dopamine and norepinephrine, unrelated to beta receptor blockade. Therefore, Amphetamine is not a beta-blocker.