Activation of central alpha2 receptors results in inhibition of cardio acceleration and centers in the brain.
- A. Vasodilation
- B. Vasoconstriction
- C. Cardiovascular
- D. Respiratory
Correct Answer: B
Rationale: Alpha2 receptor activation (e.g., by clonidine) causes vasoconstriction and reduced sympathetic outflow.
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Which statement is not correct about metformin:
- A. Is for internal use only
- B. Reduce weight, apetite
- C. More frequently causes nausea and vomiting comparing with other hypoglicemic drugs
- D. Use for diabetes mellitus type I
Correct Answer: D
Rationale: Metformin is not typically used for type 1 diabetes, which requires insulin, as it acts on insulin sensitivity and hepatic glucose production.
A characteristic that distinguishes true receptors from other drug binding sites present in blood and other biological tissues is the characteristic of:
- A. binding affinity
- B. reversible binding
- C. signal transduction
- D. stereoselective interaction
Correct Answer: B
Rationale: Reversible binding is a key feature of true receptors, distinguishing them from non-specific binding sites like plasma proteins.
A nurse is preparing to administer medications to a 4-month-old infant. Which of the following pharmacokinetic principles should the nurse consider when administering medications to this client?
- A. Infants have a more rapid gastric emptying time.
- B. Infants have normal liver function.
- C. Infants have a more rapid gastric emptying time.
- D. Infants have an increased ability to absorb topical medications.
Correct Answer: D
Rationale: Immature liver function affects metabolism, and increased topical absorption occurs due to thinner skin; rapid gastric emptying (A,C) is incorrect.
A doctor orders 250 mL of IV fluid to be infused over 1 hour using microdrip tubing (60 gtt/mL). What is the flow rate in drops per minute?
- A. 100 gtt/min
- B. 120 gtt/min
- C. 150 gtt/min
- D. 250 gtt/min
Correct Answer: D
Rationale: Flow rate = (250 mL 60 gtt/mL) ÷ (1 60) = 15,000 ÷ 60 = 250 gtt/min, matching microdrip where mL/hr = gtt/min.
The nurse uses what term to describe the drug level required to have a therapeutic effect?
- A. Critical concentration
- B. Dynamic equilibrium
- C. Selective toxicity
- D. Active transport
Correct Answer: A
Rationale: A critical concentration of a drug must be present before a reaction occurs within the cells to bring about the desired therapeutic effect. A dynamic equilibrium is obtained from absorption of a drug from the site of drug entry, distribution to the active site, metabolism in the liver, and excretion from the body to have a critical concentration. Selective toxicity is the ability of a drug to attach only to those systems found in foreign cells. Active transport is the process that uses energy to actively move a molecule across a cell membrane and is often involved in drug excretion in the kidney.
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