Sample BCPP Question 2
Which one of the following regimens represents the best choice in a 23-year old patient with schizophrenia deemed partially responsive to olanzapine 10 mg QHS? The patient has no laboratory abnormalities, no complaints of medication side effects, and affirms adherence. Past medication history is noncontributory except for tobacco use and occasional alcohol use.
- Switch to quetiapine extended release 300 mg daily
- Increase to olanzapine 10 BID
- Add aripiprazole 5 mg daily
- Switch to paliperidone depot injections
Answer: B
Rationale:
- Cigarette smoking in the presence of olanzapine use creates a clinically significant drug interaction via the CYP1A2 isoenzyme. Serum levels of olanzapine in smokers has been reported to be approximately half that of non-smokers as a result of the induction of hepatic metabolism and subsequent increase in the rate of drug clearance. An increase in the olanzapine dose represents the most rational choice since the patient achieved a partial response with what is really a low dose of olanzapine.
Reference:
- J Clin Pharmacol 2008;48:157-65.