NCLEX-Style Questions: Antidepressant Interactions & Contraindications

Question 1: A patient has been taking phenelzine (Nardil) for depression. The provider wants to switch the patient to fluoxetine (Prozac). What is the minimum washout period required before starting the SSRI?

A. 5 days
B. 7 days
C. 14 days
D. 5 weeks

Answer: C. 14 days

Rationale: MAOIs must be withdrawn at least 14 days before starting an SSRI due to the risk of serotonin syndrome. MAOIs cause irreversible inhibition of monoamine oxidase, and their effects persist long after dosing stops. Both medications increase serotonin availability—MAOIs prevent breakdown while SSRIs block reuptake—creating dangerous serotonin accumulation if combined.

Why other options are incorrect:

• A & B: Too short; insufficient time for MAO enzyme regeneration

• D: This is the washout period needed when stopping fluoxetine before starting an MAOI (due to fluoxetine's long half-life)

Question 2: A patient taking fluoxetine (Prozac) reports taking over-the-counter cold medication containing dextromethorphan. Which assessment finding would indicate a potential complication?

A. Bradycardia and hypotension
B. Fever, muscle spasms, and altered mental status
C. Urinary retention and blurred vision
D. Hyperglycemia and weight gain

Answer: B. Fever, muscle spasms, and altered mental status

Rationale: These are signs of serotonin syndrome. Dextromethorphan is a serotonergic drug that increases the risk of serotonin syndrome when combined with SSRIs. Key symptoms include fever, myoclonus (muscle spasms), altered mental state, tachycardia, sweating, and elevated blood pressure. Severe cases can progress to hyperpyrexia and cardiovascular shock.

Why other options are incorrect:

• A: Opposite of expected findings (would see tachycardia and hypertension)

• C: Anticholinergic effects, not associated with serotonin syndrome

• D: Metabolic effects seen with atypical antipsychotics, not serotonin syndrome

Question 3: A patient taking an MAOI asks about foods to avoid. Which food should the nurse emphasize carries the highest risk for hypertensive crisis?

A. Fresh fish
B. Aged cheese
C. White bread
D. Apples

Answer: B. Aged cheese

Rationale: Aged cheeses are extremely rich in tyramine. MAOIs inhibit intestinal and hepatic MAO, allowing dietary tyramine to enter systemic circulation intact. Tyramine then stimulates massive norepinephrine release from sympathetic nerves, causing severe vasoconstriction and cardiac stimulation, resulting in hypertensive crisis. Other high-tyramine foods include pickled/smoked fish and wine.

Question 4: A nurse is caring for a patient taking venlafaxine (Effexor) 225 mg daily. Which assessment finding requires immediate follow-up?

A. Blood pressure 158/96 mmHg
B. Weight loss of 3 pounds over 2 weeks
C. Report of mild nausea after doses
D. Difficulty achieving orgasm

Answer: A. Blood pressure 158/96 mmHg

Rationale: Venlafaxine causes dose-related sustained diastolic hypertension. Blood pressure should be monitored at baseline and with dose changes. Elevated BP requires immediate intervention as it can lead to cardiovascular complications.

Why other options are incorrect:

• B: Dose-dependent weight loss is an expected side effect secondary to anorexia

• C: Nausea is the most common side effect (37-58% of patients)

• D: Sexual dysfunction is a known side effect but not immediately life-threatening

Question 5: A pregnant patient at 36 weeks gestation has been taking fluoxetine (Prozac) throughout pregnancy. What should the nurse monitor in the newborn after delivery?

A. Hypoglycemia and jaundice
B. Irritability, abnormal crying, and respiratory distress
C. Macrosomia and birth trauma
D. Hypotonia and poor feeding only

Answer: B. Irritability, abnormal crying, and respiratory distress

Rationale: Use of SSRIs late in pregnancy poses risk for neonatal abstinence syndrome (NAS) and persistent pulmonary hypertension of the newborn (PPHN). NAS is characterized by irritability, abnormal crying, tremor, respiratory distress, and possibly seizures. The syndrome can be managed with supportive care and generally abates within a few days. Infants exposed to SSRIs late in gestation should be monitored closely for both NAS and PPHN.

Question 6: A patient taking fluoxetine (Prozac) is prescribed ibuprofen for arthritis pain. What adverse effect should the nurse monitor for with this combination?

A. Serotonin syndrome
B. Gastrointestinal bleeding
C. Hypertensive crisis
D. Agranulocytosis

Answer: B. Gastrointestinal bleeding

Rationale: SSRIs impede platelet aggregation by blocking serotonin uptake (platelets require 5-HT for aggregation). This causes a threefold increase in GI bleeding risk. Caution is advised when combining SSRIs with NSAIDs, in patients with ulcers or GI bleeding history, patients over 60, and those taking anticoagulants.