Nokea
antagonist is a substance that:
- A. Binds to the receptors and initiates changes in cell function, producing maximal effect
- B. Binds to the receptors and initiates changes in cell function, producing submaximal effect
- C. Interacts with plasma proteins and doesn't produce any effect
- D. Binds to the receptors without directly altering their functions
Correct Answer: D
Rationale: An antagonist binds receptors without activating them, blocking agonist effects.
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A patient wants to know about the possible interactions of the various drugs that he has been prescribed for an illness. The nurse explains that the drugs interact with each other and produce an effect that is greater than the sum of their separate actions. Which of the following reactions is the nurse informing about?
- A. Additive drug reaction
- B. Synergistic drug reaction
- C. Antagonistic drug reaction
- D. Toxic drug reaction
Correct Answer: B
Rationale: A synergistic drug reaction occurs when drugs interact with each other and produce a sum greater than the sum of their separate actions. An additive drug reaction occurs when the combined effect of two drugs is equal to the sum of each drug given alone. An antagonistic drug reaction occurs when one drug interferes with the action of another, causing neutralization or a decrease in the effect of one drug. Toxic drug reactions are caused when blood concentration levels exceed the therapeutic levels of a drug.
Which of the following inhibit production of triiodethyronine (T4) from tetraiodethyronine (T3)?
- A. Iodides
- B. Thiocyanate
- C. Perchlorate
- D. Amiodarone
Correct Answer: D
Rationale: Amiodarone inhibits the peripheral conversion of T4 to T3, reducing active thyroid hormone levels.
After admitting a patient to the unit, the nurse is organizing times to administer ordered medications. What important consideration will guide the nurse's timing of each medication?
- A. Comfort
- B. Ethnicity of patient
- C. Gender
- D. Age
Correct Answer: D
Rationale: Age affects metabolism and timing needs (e.g., elderly may need adjusted schedules).
Janie presents to the clinic with hard ear wax in both ear canals. Instructions regarding home removal of hard cerumen include:
- A. Moisten a cotton swab (Q-tip) and swab the ear canal twice daily
- B. Instill tap water in both ears while bathing
- C. Squirt hydrogen peroxide into ears with each bath
- D. Instill carbamide peroxide (Debrox) twice daily until canals are clear
Correct Answer: D
Rationale: Carbamide peroxide softens cerumen safely; Q-tips risk impaction, and water or peroxide are less effective.
Which of the following is a disadvantage of using oral drugs
- A. First pass effect
- B. Low bioavailability
- C. Overdose overcome by antidotes
- D. A and B
Correct Answer: D
Rationale: Oral drugs face the first-pass effect and often have lower bioavailability due to liver metabolism, making D (A and B) the correct combined disadvantage.