Sample Questions
1. A 20 y.o. male recently diagnosed with schizophrenia has been treated with Risperdal 1mg. BID for eight weeks and has had no side effects. One week ago he was started on an antidepressant and he is now in your office complaining of stiffness in his arms and legs. Which antidepressant was he most likely given?
a. Duloxetine
b. Venlafaxine
c. Imipramine
d. Citalopram
Answer: a. This is a drug drug interaction occurring at the cytochrome P450 2D6 enzyme. Risperidone is a substrate and duloxetine is an inhibitor. Therefore the patient's risperidone levels became increased when the enzyme was inhibited by the addition of duloxetine. The other antidepressants have little or no effect on the 2D6 enzyme.
2. Which of the following medications can decrease plasma lithium levels?
a. Ibuprofen
b. Carbamazepine
c. Hydrochlorthiazide
d. Lisinopril
e. Theophyline
Answer: e. NSAIDS, thiazide diuretics and ACE inhibitors all can INCREASE plasma lithium levels. Theophylline causes increased excretion of Lithium, and DECREASED plasma levels. Lithium is renally excreted and is not affected by P450 drug interactions and therefore Carbamazepine has no significant effect on plasma levels.
3. A 32 yo single female was diagnosed with schizophrenia, paranoid subtype 6 months ago. Her sx began shortly after she dropped out of from high school, although she refused to seek treatment until 6 months ago. Which of the following is a good prognostic indicator?
a. her marital status
b. her level of academic achievement
c. her diagnostic subtype
d. her age of onset of illness
e. the time interval from symptom onset to start of treatment
Answer: c. The paranoid subtype confers a good prognosis in schizophrenia. Early age of onset, low academic achievement, early age of onset and long duration until treatment begins are all poor prognostic indicators.
