A client with treatment-resistant schizophrenia is starting … | MyMerci
Medical EmergenciesPA
Question
A client with treatment-resistant schizophrenia is starting clozapine. Which baseline laboratory test must be documented before each dispensing of the medication?
1Hemoglobin A1c
2Absolute neutrophil count (ANC)✓ Correct answer
3Liver enzymes
4Serum sodium
Explanation
Correct (2): Clozapine carries a boxed warning for severe agranulocytosis (~1% incidence). The Clozapine REMS program requires documented ANC ≥1500/mm³ before each dispense — weekly for the first 6 months, biweekly months 7-12, then monthly thereafter. The drug must be held if ANC
In-depth explanation
Memory Tip "Clozapine = ANC clock" — weekly × 6 months, biweekly × 6 months, then monthly. Caution Clients must report fever, sore throat, mouth ulcers, or flu-like symptoms IMMEDIATELY — infection during clozapine-induced neutropenia can be fatal. Clinical Practice Guide Pharmacies cannot dispense without a current ANC documented in REMS; missed labs interrupt therapy.
Clinical scenario
Scenario A 28-year-old male with treatment-resistant schizophrenia has failed adequate trials of olanzapine and risperidone. The provider prescribes clozapine 12.5 mg PO BID with a planned titration. REMS program enrollment is complete and the pharmacy is awaiting clearance to dispense.
Key concepts
Clozapine REMS — A national restricted-distribution program requiring documented ANC monitoring at specified intervals; pharmacies cannot dispense clozapine without a current result.
Agranulocytosis — Severe neutropenia (ANC
Treatment-resistant schizophrenia — Schizophrenia that has failed adequate trials of at least two other antipsychotics; clozapine is uniquely effective and is the recommended next-line agent.