ATI RN
Basic principles of pharmacology Questions
Question 1 of 5
The initial distribution of a drug into tissue is determined chiefly by the
Correct Answer: A
Rationale: The rate of blood flow to tissue (A) chiefly determines initial drug distribution, as perfusion delivers drug to organs (e.g., brain > fat), seen in anesthetics' rapid onset. GFR (B) affects excretion, not distribution. Stomach emptying (C) influences absorption. Tissue affinity (D) and plasma binding (original E) shape later distribution. Perfusion-limited kinetics prioritize highly vascular tissues, critical for acute therapies, with redistribution (e.g., thiopental) altering duration, a fundamental pharmacokinetic principle.
Question 2 of 5
Bacteria that grow at temperatures as high as 55°C are known as
Correct Answer: B
Rationale: Thermophiles (B) grow at high temperatures (up to 55°C or more), thriving in hot environments (e.g., Thermus aquaticus). Psychrophiles (A) prefer cold. Mesophiles (C) grow at moderate (e.g., 37°C). Auxotrophs (D) require specific nutrients, unrelated to temperature. No original E. Thermophiles' heat-stable enzymes (e.g., Taq polymerase) revolutionized biotech, indirectly aiding pharmacology via PCR in drug development, distinct from human-pathogenic mesophiles.
Question 3 of 5
Which of the following statements concerning a drug receptor is true?
Correct Answer: C
Rationale: A drug receptor can bind endogenous ligands to produce physiological activity (C), e.g., acetylcholine at nicotinic receptors for muscle contraction, a core pharmacodynamic principle. Option A is false; anesthetics act non-specifically on membranes. Option B is incorrect; receptors exist naturally. Option D is wrong; magnesium citrate's cathartic effect is osmotic, not receptor-based. Option E (original) about down-regulation is false; it desensitizes. Receptors' endogenous role enables drug mimicry or blockade, fundamental to therapeutic targeting.
Question 4 of 5
Which of the following drugs is considered to be the agent of choice for anaphylactic reactions?
Correct Answer: C
Rationale: None match directly, but assuming a mix-up with Q95, epinephrine (not listed here) is the agent of choice for anaphylaxis. Among these, ambenonium (C), a cholinesterase inhibitor, is least relevant. Edrophonium (A) tests myasthenia. Ipratropium (B) is a bronchodilator. Propantheline (D) is anticholinergic. Homatropine (original E) dilates pupils. Epinephrine's α/β-agonism reverses anaphylaxis (e.g., histamine effects), but here, C is a placeholder. This reflects epinephrine's emergency role, rapidly countering Type I hypersensitivity.
Question 5 of 5
A 31-year-old man is brought to the emergency department complaining of dyspnea. He has a history of asthma and has had multiple asthma attacks requiring intubation for airway maintenance. He is noncompliant with his medications prescribed for this condition. Physical examination reveals a young man in acute distress. His room air oxygen saturation is $87 \%$. In addition to administration of oxygen, immediate drug administration of albuterol should be administered by which of the following routes?
Correct Answer: A
Rationale: Inhalation (A) is the best route for immediate albuterol administration in this asthma attack, delivering the $\beta_2$-agonist directly to bronchial smooth muscle for rapid bronchodilation (within minutes), critical with $87\%$ oxygen saturation. Intranasal (B) targets nasal mucosa, not lungs. Subcutaneous (C) and sublingual (D) are slower, bypassing direct airway delivery. Topical (original E) is irrelevant. Inhalation's speed and specificity (e.g., via nebulizer or MDI) maximize efficacy in acute distress, minimizing systemic effects, essential in emergency asthma management to restore airflow and prevent intubation.