Nokea
A 62-year-old man with a history of myocardial infarction and angina has a prescription for sublingual nitroglycerine but has not taken it. He now complains of erectile dysfunction and is given a prescription for sildenafil 50 mg. He is warned by his physician not to take sildenafil and nitroglycerine because of which of the following possible reactions?
- A. Hypotension
- B. Myocardial infarction
- C. Retinitis pigmentosa
- D. Tinnitus
Correct Answer: A
Rationale: Sildenafil and nitroglycerin both enhance vasodilation (via cGMP and NO), risking severe hypotension if combined.
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Indication of vitamin D3 is:
- A. Hypercalcemia
- B. Paget's disease
- C. Hypophosphatemia
- D. Osteomalacia
Correct Answer: D
Rationale: The correct answer is D: Osteomalacia. Vitamin D3 is indicated for the treatment of osteomalacia, a condition characterized by softening of the bones due to a deficiency of vitamin D. It helps in the absorption of calcium and phosphorus, leading to proper bone mineralization.
A: Hypercalcemia is not an indication for vitamin D3 as it can worsen the condition by increasing calcium levels further.
B: Paget's disease is not a primary indication for vitamin D3 therapy. Treatment usually involves bisphosphonates.
C: Hypophosphatemia is a condition where there is low phosphate levels, and treatment involves phosphate supplementation, not just vitamin D3.
Indicate the antiseizure drug – a benzodiazepine receptor agonist:
- A. Phenobarbital
- B. Phenytoin
- C. Carbamazepine
- D. Lorazepam
Correct Answer: D
Rationale: The correct answer is D: Lorazepam. Lorazepam is a benzodiazepine receptor agonist, which enhances the inhibitory effect of GABA in the brain, reducing neuronal excitability and preventing seizures. Phenobarbital (A) acts by enhancing GABAergic transmission but is not a benzodiazepine. Phenytoin (B) works by blocking sodium channels. Carbamazepine (C) also blocks sodium channels but is not a benzodiazepine receptor agonist. Therefore, D is the correct answer as it directly acts on the benzodiazepine receptor to control seizures.
All the following adverse effects can be produced by beta-blockers EXCEPT:
- A. Hypotension
- B. Cold extremities
- C. Tachycardia
- D. Bronchospasm especially in asthmatic patients
Correct Answer: C
Rationale: Beta-blockers cause hypotension (A), cold extremities (B), and bronchospasm (D), but reduce heart rate, not cause tachycardia (C).
The mechanism of haloperidol antipsychotic action is:
- A. Blocking D2 receptors
- B. Central alpha-adrenergic blocking
- C. Inhibition of norepinephrine uptake mechanisms
- D. All of the above
Correct Answer: A
Rationale: The correct answer is A: Blocking D2 receptors. Haloperidol is a typical antipsychotic that primarily works by blocking dopamine D2 receptors in the brain, leading to a reduction in dopamine activity and alleviating psychotic symptoms. Choices B and C are incorrect as haloperidol does not primarily act by central alpha-adrenergic blocking or inhibition of norepinephrine uptake mechanisms. Choice D, "All of the above," is incorrect as haloperidol's main mechanism of action is through D2 receptor blockade, not through all the mechanisms listed.
The client has atrial fibrillation. What can the nurse say about the P wave?
- A. It precedes a long PR interval
- B. It falls on the previous T wave
- C. The P wave is absent
- D. It is peaked
Correct Answer: C
Rationale: In atrial fibrillation, P waves are absent, replaced by chaotic fibrillatory waves due to disorganized atrial activity.