Psychopharmacology represents a cornerstone of psychiatric-mental health nurse practitioner practice and constitutes a significant portion of the PMHNP-BC certification examination across multiple content domains. Mastery of psychotropic medications, including their mechanisms of action, pharmacokinetics, pharmacodynamics, and clinical applications, is essential for safe and effective patient care in mental health settings. Understanding the complex interactions between psychiatric medications and the cytochrome P450 enzyme system enables practitioners to anticipate drug-drug interactions and adjust treatment plans accordingly. Knowledge of medication side effect profiles, contraindications, and monitoring requirements allows PMHNPs to balance therapeutic benefits against potential risks while optimizing patient outcomes. The ability to recognize and manage serious adverse effects, such as serotonin syndrome, neuroleptic malignant syndrome, and metabolic complications, can be life-saving in clinical practice. Competency in psychopharmacology extends beyond memorizing drug names and doses to include understanding the neurobiological basis of psychiatric disorders and how medications modulate neurotransmitter systems. PMHNPs must demonstrate proficiency in medication selection based on patient-specific factors, including age, comorbidities, concurrent medications, genetic variations, and previous treatment responses. The integration of evidence-based prescribing practices with patient-centered care requires ongoing knowledge of current clinical guidelines and emerging research in psychopharmacology. Understanding the principles of medication titration, augmentation strategies, and safe medication discontinuation is crucial for managing complex psychiatric conditions across the lifespan. These practice questions are designed to test your comprehensive understanding of psychopharmacology principles, preparing you for both the PMHNP-BC certification examination and the clinical decision-making challenges you will encounter in psychiatric practice.
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## Practice Questions
**Question 1:** A 35-year-old patient with major depressive disorder has been taking sertraline 100 mg daily for 6 weeks with minimal improvement. What is the most appropriate next step?
A) Discontinue sertraline immediately and start a different SSRI
B) Increase sertraline to 150 mg daily and reassess in 2-4 weeks
C) Add bupropion for augmentation
D) Switch to a tricyclic antidepressant
**Correct Answer:** B) Increase sertraline to 150 mg daily and reassess in 2-4 weeks
**Explanation:** The therapeutic dose range for sertraline is 50-200 mg daily. Before switching medications or adding augmentation, it’s appropriate to optimize the current medication by increasing to a higher therapeutic dose, as the patient is only at a moderate dose. Full response may take 8-12 weeks.
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**Question 2:** Which cytochrome P450 enzyme is primarily responsible for metabolizing most antipsychotic medications?
A) CYP1A2
B) CYP2D6
C) CYP3A4
D) CYP2C19
**Correct Answer:** B) CYP2D6
**Explanation:** CYP2D6 is the primary enzyme responsible for metabolizing most antipsychotic medications, including risperidone, haloperidol, and aripiprazole. Genetic variations in CYP2D6 can significantly affect drug metabolism, leading to poor, intermediate, extensive, or ultra-rapid metabolizer phenotypes.
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**Question 3:** A patient taking lithium for bipolar disorder presents with a lithium level of 1.8 mEq/L. Which symptom would you most likely observe?
A) Mild hand tremor
B) Polyuria and polydipsia
C) Confusion and ataxia
D) No symptoms, this is therapeutic
**Correct Answer:** C) Confusion and ataxia
**Explanation:** A lithium level of 1.8 mEq/L indicates moderate toxicity (1.5-2.0 mEq/L). Symptoms include confusion, ataxia, coarse tremor, muscle twitching, and slurred speech. The therapeutic range is 0.6-1.2 mEq/L. Mild hand tremor and polyuria can occur at therapeutic levels.
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**Question 4:** Which antidepressant should be avoided in patients with a history of seizure disorder?
A) Sertraline
B) Bupropion
C) Escitalopram
D) Mirtazapine
**Correct Answer:** B) Bupropion
**Explanation:** Bupropion is contraindicated in patients with seizure disorders or conditions that increase seizure risk (e.g., eating disorders, abrupt alcohol/benzodiazepine withdrawal) because it lowers the seizure threshold in a dose-dependent manner. The risk is approximately 0.4% at doses up to 450 mg/day.
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**Question 5:** A patient on clozapine develops an absolute neutrophil count (ANC) of 900 cells/mm³. What is the appropriate action?
A) Continue clozapine and recheck ANC in 1 week
B) Reduce clozapine dose by 50%
C) Discontinue clozapine immediately and do not rechallenge
D) Hold clozapine and monitor ANC daily until it rises above 1000
**Correct Answer:** C) Discontinue clozapine immediately and do not rechallenge
**Explanation:** An ANC below 1000 cells/mm³ indicates severe neutropenia. Clozapine must be discontinued immediately, and the patient should not be rechallenged due to the risk of agranulocytosis. This is a medical emergency requiring hematology consultation.
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**Question 6:** What is the mechanism of action of buspirone?
A) GABA-A receptor agonist
B) Serotonin 5-HT1A partial agonist
C) Norepinephrine reuptake inhibitor
D) Benzodiazepine receptor agonist
**Correct Answer:** B) Serotonin 5-HT1A partial agonist
**Explanation:** Buspirone is a serotonin 5-HT1A partial agonist used for generalized anxiety disorder. Unlike benzodiazepines, it does not cause sedation, dependence, or withdrawal. It takes 2-4 weeks to achieve therapeutic effect and is not effective for acute anxiety or panic attacks.
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**Question 7:** A patient taking an MAOI consumes aged cheese and develops severe hypertension, headache, and diaphoresis. This reaction is caused by:
A) Serotonin syndrome
B) Tyramine crisis
C) Neuroleptic malignant syndrome
D) Anticholinergic toxicity
**Correct Answer:** B) Tyramine crisis
**Explanation:** MAOIs inhibit the breakdown of tyramine, a substance found in aged cheeses, cured meats, and fermented foods. Consuming tyramine-rich foods while on MAOIs can cause a hypertensive crisis. Treatment includes phentolamine or nifedipine for blood pressure control.
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**Question 8:** Which atypical antipsychotic has the highest risk of metabolic syndrome?
A) Aripiprazole
B) Ziprasidone
C) Olanzapine
D) Lurasidone
**Correct Answer:** C) Olanzapine
**Explanation:** Olanzapine and clozapine have the highest risk of metabolic side effects, including weight gain, dyslipidemia, and diabetes. Aripiprazole, ziprasidone, and lurasidone have lower metabolic risk profiles. Regular monitoring of weight, glucose, and lipids is essential for all patients on antipsychotics.
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**Question 9:** What is the recommended washout period when switching from fluoxetine to an MAOI?
A) 2 weeks
B) 3 weeks
C) 5 weeks
D) 1 week
**Correct Answer:** C) 5 weeks
**Explanation:** Fluoxetine has a long half-life (4-6 days) and its active metabolite norfluoxetine has an even longer half-life (4-16 days). A 5-week washout period is required before starting an MAOI to prevent serotonin syndrome. For other SSRIs, a 2-week washout is typically sufficient.
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**Question 10:** A patient on valproate presents with elevated ammonia levels but normal liver function tests. What is the most likely diagnosis?
A) Hepatotoxicity
B) Hyperammonemic encephalopathy
C) Pancreatitis
D) Thrombocytopenia
**Correct Answer:** B) Hyperammonemic encephalopathy
**Explanation:** Valproate can cause hyperammonemia without hepatotoxicity, leading to encephalopathy with symptoms of confusion, lethargy, and cognitive impairment. This can occur even with therapeutic valproate levels. Treatment involves discontinuing or reducing valproate and considering L-carnitine supplementation.
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**Question 11:** Which medication requires baseline and periodic ECG monitoring due to QTc prolongation risk?
A) Citalopram
B) Venlafaxine
C) Duloxetine
D) Bupropion
**Correct Answer:** A) Citalopram
**Explanation:** Citalopram carries an FDA warning for dose-dependent QTc prolongation. The maximum recommended dose is 40 mg daily (20 mg for patients over 60 or with hepatic impairment). Baseline and periodic ECG monitoring is recommended, especially in patients with cardiac risk factors.
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**Question 12:** A patient taking lamotrigine develops a rash 3 weeks after starting the medication. What is the primary concern?
A) Common benign rash requiring no action
B) Stevens-Johnson syndrome/toxic epidermal necrolysis
C) Contact dermatitis from medication handling
D) Allergic reaction requiring antihistamines only
**Correct Answer:** B) Stevens-Johnson syndrome/toxic epidermal necrolysis
**Explanation:** Lamotrigine carries a black box warning for serious rashes, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which can be life-threatening. Any rash developing during lamotrigine treatment requires immediate discontinuation and medical evaluation. Slow titration reduces but does not eliminate this risk.
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**Question 13:** What is the primary advantage of long-acting injectable (LAI) antipsychotics over oral formulations?
A) Fewer side effects
B) Improved medication adherence
C) Lower cost
D) Faster onset of action
**Correct Answer:** B) Improved medication adherence
**Explanation:** LAI antipsychotics improve medication adherence by eliminating the need for daily oral dosing, which is particularly beneficial for patients with poor insight or adherence issues. They do not have fewer side effects or faster onset, and are typically more expensive than oral formulations.
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**Question 14:** Which benzodiazepine is preferred for patients with hepatic impairment?
A) Diazepam
B) Alprazolam
C) Lorazepam
D) Clonazepam
**Correct Answer:** C) Lorazepam
**Explanation:** Lorazepam, oxazepam, and temazepam (LOT) undergo direct glucuronidation and do not require hepatic oxidation, making them safer choices for patients with hepatic impairment. Other benzodiazepines undergo hepatic metabolism via CYP450 enzymes and can accumulate in liver disease.
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**Question 15:** A patient on venlafaxine 225 mg daily reports persistent elevated blood pressure. What is the most appropriate intervention?
A) Add an antihypertensive medication
B) Switch to a different SNRI
C) Reduce venlafaxine dose or switch to an SSRI
D) Continue current dose and monitor blood pressure
**Correct Answer:** C) Reduce venlafaxine dose or switch to an SSRI
**Explanation:** Venlafaxine can cause dose-dependent increases in blood pressure, particularly at doses above 150 mg daily. The most appropriate intervention is to reduce the dose or switch to an SSRI, which has minimal effect on blood pressure. If the antidepressant effect is needed at higher doses, adding an antihypertensive may be considered.
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## Conclusion
These 15 practice questions cover essential psychopharmacology concepts that every PMHNP must master for both the certification examination and clinical practice. Focus on understanding the mechanisms of action, side effect profiles, drug interactions, and clinical decision-making principles. Continue practicing with additional questions and reviewing current psychopharmacology guidelines to build confidence and competence in psychiatric medication management.