MTM Behavioral Health Pharmacotherapy 2 — Questions and Answers
Question 1: A patient with bipolar I disorder is started on lithium. Which laboratory parameter is most critical to monitor for toxicity?
- Serum creatinine
- Serum lithium level (Correct answer)
- Liver function tests
- Complete blood count
Correct answer: Serum lithium level
Serum lithium levels must be monitored closely because the therapeutic window is narrow (0.6–1.2 mEq/L) and toxicity occurs at levels above 1.5 mEq/L.
Question 2: Which antipsychotic is most associated with QTc prolongation and requires baseline and periodic ECG monitoring?
- Aripiprazole
- Quetiapine
- Ziprasidone (Correct answer)
- Olanzapine
Correct answer: Ziprasidone
Ziprasidone is associated with the greatest QTc prolongation among atypical antipsychotics, necessitating ECG monitoring and avoidance with other QTc-prolonging drugs.
Question 3: An MTM pharmacist is reviewing a patient taking sertraline who reports new-onset agitation, tremor, hyperthermia, and diarrhea after adding linezolid. What is the most likely diagnosis?
- Neuroleptic malignant syndrome
- Serotonin syndrome (Correct answer)
- Anticholinergic toxicity
- Benzodiazepine withdrawal
Correct answer: Serotonin syndrome
Serotonin syndrome presents with the triad of mental status changes, autonomic instability, and neuromuscular abnormalities, and can occur when SSRIs are combined with linezolid (an MAO inhibitor).
Question 4: Which benzodiazepine is preferred in elderly patients due to its lack of active metabolites?
- Diazepam
- Chlordiazepoxide
- Lorazepam (Correct answer)
- Clonazepam
Correct answer: Lorazepam
Lorazepam undergoes direct glucuronidation without producing active metabolites, making it safer in elderly patients whose hepatic function may be reduced.
Question 5: A patient with schizophrenia on clozapine develops an absolute neutrophil count (ANC) of 900 cells/mm³. What is the most appropriate action?
- Continue clozapine and recheck ANC in 1 week
- Reduce the clozapine dose by 50%
- Discontinue clozapine immediately (Correct answer)
- Add granulocyte colony-stimulating factor and continue clozapine
Correct answer: Discontinue clozapine immediately
Per REMS guidelines, clozapine must be discontinued immediately if ANC falls below 1000 cells/mm³ (severe neutropenia) to prevent agranulocytosis.
Question 6: Which medication used in alcohol use disorder works by blocking opioid receptors to reduce alcohol cravings?
- Disulfiram
- Acamprosate
- Naltrexone (Correct answer)
- Topiramate
Correct answer: Naltrexone
Naltrexone is an opioid antagonist that reduces the rewarding effects of alcohol and decreases craving by blocking mu-opioid receptors.
Question 7: A patient taking phenelzine for depression eats aged cheese and develops a severe hypertensive crisis. What interaction caused this?
- Phenelzine blocking histamine receptors
- Tyramine accumulation due to MAO inhibition (Correct answer)
- Calcium channel activation by phenelzine
- Direct vasopressor effect of cheese proteins
Correct answer: Tyramine accumulation due to MAO inhibition
MAO inhibitors like phenelzine prevent breakdown of tyramine (found in aged foods), causing excessive norepinephrine release and potentially fatal hypertensive crisis.
MTM Behavioral Health Pharmacotherapy 2
A patient with bipolar I disorder is started on lithium.
Which laboratory parameter is most critical to monitor for toxicity?