ATI RN
Ch 30 principles of pharmacology Questions
Question 1 of 5
Divided powders may be dispensed in
Correct Answer: A
Rationale: Divided powders are dispensed in individual-dose packets (A), pre-measured paper or foil packets (e.g., headache powders) ensuring accurate dosing and convenience. Bulk containers (B) suit undivided powders. Sifter-type containers (C) are for topical use, not oral doses. No option D or original E exists. This packaging protects hygroscopic or unstable drugs, enhancing patient compliance and stability, a traditional yet effective dispensing method in pharmacy practice.
Question 2 of 5
The intensity of the pharmacologic action of a drug is most dependent on the
Correct Answer: A
Rationale: The intensity of pharmacologic action depends most on the concentration of the drug at the receptor site (A), as receptor occupancy drives effect (e.g., acetylcholine at muscarinic receptors), per the law of mass action. Half-life (B) affects duration, not intensity. Onset time (C) reflects absorption, not effect strength. MTC (D) and MEC (original E) are plasma thresholds, not receptor levels. This receptor-centric principle, foundational to pharmacodynamics, links dose, distribution, and response, guiding therapeutic efficacy and titration.
Question 3 of 5
Which tissue has the greatest capacity to bio-transform drugs?
Correct Answer: C
Rationale: The liver (C) has the greatest capacity to bio-transform drugs, via enzymes like CYP450 (e.g., oxidizing codeine to morphine), handling most metabolism due to its size and enzyme abundance. Brain (A) and kidney (B) have limited roles. Lung (D) metabolizes some (e.g., nicotine), less than liver. Skin (original E) is minimal. The liver's first-pass effect and phase I/II reactions (e.g., glucuronidation) detoxify and excrete drugs, central to pharmacokinetics, impacting bioavailability and clearance.
Question 4 of 5
Which of the following compounds are considered the building blocks of nucleic acids?
Correct Answer: A
Rationale: Nucleotides (A) are the building blocks of nucleic acids (DNA/RNA), comprising a sugar, phosphate, and base (e.g., ATP), polymerized via phosphodiester bonds. Nucleosides (B) lack phosphate. Monosaccharides (C) build carbohydrates. Purines (D) and amino acids (original E) are components, not full units. Nucleotides' role in genetic material and energy (e.g., GTP) underpins antiviral drugs (e.g., acyclovir), targeting replication, a critical biochemical and pharmacological concept.
Question 5 of 5
Which of the following organisms can use only molecular oxygen as the final acceptor?
Correct Answer: C
Rationale: Obligate aerobes (C) use only molecular oxygen as the final electron acceptor in respiration (e.g., Mycobacterium tuberculosis), requiring Oâ‚‚ for survival. Obligate (A) and strict anaerobes (D) die with oxygen, using alternatives (e.g., nitrate). Facultative anaerobes (B) adapt to both. No original E. This oxygen dependence affects pathogenicity and drug targeting (e.g., TB's aerobic metabolism), contrasting with anaerobes like Clostridium, key in microbiology and antimicrobial therapy.