Nokea
Methotrexate is:
- A. A purine antagonist
- B. A folic acid antagonist
- C. An antibiotic
- D. An alkylating agent
Correct Answer: B
Rationale: Methotrexate is a folic acid antagonist. It inhibits dihydrofolate reductase, leading to decreased DNA synthesis. This action makes it effective in treating cancer and autoimmune diseases. Purine antagonists target purine synthesis, antibiotics act on bacterial growth, and alkylating agents damage DNA to prevent cell division. Methotrexate's mechanism aligns with folic acid antagonism, making option B the correct choice.
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Indicate the anxiolitic agent,which relieves anxiety without causing marked sedative effects:
- A. Diazepam
- B. Chlordiazepoxid
- C. Buspirone
- D. Clorazepate
Correct Answer: C
Rationale: The correct answer is C: Buspirone. Buspirone is an anxiolytic agent that relieves anxiety without causing marked sedative effects. It works by specifically targeting serotonin receptors in the brain to reduce anxiety, unlike benzodiazepines like Diazepam, Chlordiazepoxide, and Clorazepate which act on GABA receptors leading to sedative effects. Buspirone's unique mechanism of action makes it an ideal choice for treating anxiety without causing sedation.
The client has a heart rate of 70 and a P wave that comes early and is malformed. What is the likely cause of this?
- A. Normal sinus rhythm
- B. Premature atrial contractions
- C. Frequent PVCs
- D. Ventricular escape rhythm
Correct Answer: B
Rationale: Early, malformed P waves indicate premature atrial contractions (PACs), ectopic atrial beats.
A 10-year-old patient will be started on methylphenidate hydrochloride (Ritalin) therapy. The nurse will perform which essential baseline assessment before this drug is started?
- A. Eye examination
- B. Height and weight
- C. Liver studies
- D. Hearing test
Correct Answer: B
Rationale: The correct answer is B: Height and weight. Before starting methylphenidate therapy in a 10-year-old patient, it is essential to assess height and weight as this medication can affect growth and appetite. Monitoring these parameters at baseline helps establish a reference point for future assessment of treatment effects on growth. Eye examination (A) is important for long-term monitoring but not essential before starting therapy. Liver studies (C) are not typically required before starting methylphenidate therapy. Hearing test (D) is not directly related to starting this medication.
Tick the second messenger of G-protein-coupled (metabotropi receptor:
- A. Adenylyl cyclase
- B. Sodium ions
- C. Phospholipase C
- D. cAMP
Correct Answer: D
Rationale: The correct answer is D: cAMP. G-protein-coupled receptors activate adenylyl cyclase, leading to the production of cAMP, which acts as the second messenger. cAMP then triggers downstream signaling cascades. Choice A (Adenylyl cyclase) is the enzyme activated by G-protein-coupled receptors, not a second messenger itself. Choice B (Sodium ions) is not typically involved in GPCR signaling pathways. Choice C (Phospholipase C) generates inositol trisphosphate and diacylglycerol, which are part of a separate signaling pathway, not the second messenger system for GPCRs.
Which of the following antipsychotic agents is preferable in patients with coronary and cerebrovascular disease?
- A. Chlorpromazine
- B. Fluphenazine
- C. Haloperidol
- D. Perphenazine
Correct Answer: C
Rationale: The correct answer is C: Haloperidol. Haloperidol is preferable in patients with coronary and cerebrovascular disease due to its lower risk of causing cardiovascular adverse effects compared to the other options. Chlorpromazine (A) can cause orthostatic hypotension and prolong QT interval. Fluphenazine (B) can lead to QT prolongation and hypotension. Perphenazine (D) also carries a risk of QT prolongation and orthostatic hypotension. In contrast, Haloperidol has a more favorable cardiovascular safety profile, making it the preferred choice for patients with coronary and cerebrovascular disease.