When should Clozaril or Tegretol be discontinued?

• A. WBC < 2000 or ANC < 1000
• B. WBC < 4000 or ANC < 2000
• C. WBC < 3000 or ANC < 1500
• D. WBC < 5000 or ANC < 2500

Answer: (A)

Both Clozaril and Tegretol carry a real risk of suppressing the bone marrow, leading to leukopenia or neutropenia, which can allow infections to take hold quickly. When the white blood cell count falls below a level like 2000, or the absolute neutrophil count drops below 1000, the body’s ability to fight infection is compromised enough that continuing the medication becomes unsafe. Stopping the drug at these thresholds protects the patient while counts recover, and re-evaluation or cautious re-challenge would only be considered under strict supervision after hematologic recovery. Other thresholds would either trigger discontinuation too early or fail to offer adequate protection against serious infection, so the given cutoffs represent the appropriate safety signal for these drugs.