Clozapine monitoring

Zhang M, Owen RR, Pope SK, Smith GR. Cost-effectiveness of clozapine monitoring after the first 6 months. Arch Gen Psychiatry... 

As part of a risk niinirnisation programme (e.g. clozapine monitoring scheme)... 

Investigations (check clozapine monitoring service requirements) ... 

Many Trusts run nurse-led clozapine clinics, which oversee monitoring and liaise between the clozapine monitoring service and hospital pharmacy. They may provide linked services, e.g. psychoeducation and monitoring of physical health, MSE and side effects. Contact the clinic and introduce Peter to the staff before discharge, to smooth the transition. He ll still need CMHT follow-up and a CC. Advise Peter to seek help for any signs of constipation or infection (especially chest infection). 

You ll receive an amber result from the clozapine monitoring service. Although you can continue to prescribe clozapine, they ll advise extra blood tests, and close monitoring for fever. 

Liaise with pharmacy and the clozapine monitoring service regarding retitration and ongoing monitoring (may now need weekly FBCs, even if he d reached monthly testing)... 

Note that only a 1-week supply of clozapine is dispensed at a time. The drug is obtained through a special program designed to ensure the required blood monitoring. Weekly WBC laboratory tests are required. Immediately report any signs of weakness, fever, sore throat, malaise, or flu-like symptoms to the primary care provider. 

TABLE 34-11. Monitoring of White Blood Cell Count and Absolute Neutrophil Count during Clozapine Treatment... 

Jerling M, Lindstrom L, Bondesson U, Bertilsson L. Fluvoxamine inhibition and carbamazepine induction of the metabolism of clozapine evidence from a therapeutic drug monitoring service. 

Niederlander H.A.G. et al., 2006. High throughtput therapeutic drug monitoring of clozapine and metabolites in serum by online coupling of solid phase extraction with liquid chromatography-mass spectrometry. J Chromatogr B 834 98. 

Clozapine is available only through a distribution system that ensures monitoring of WBC counts according to the schedule described below prior to delivery of the next supply of medication. 

Monitoring Patients must have a blood sample drawn for a WBC count before initiation of treatment with clozapine and must have subsequent WBC counts done at least weekly for the first 6 months of continuous treatment. If WBC counts remain acceptable (WBC at least 3,000/mm, absolute neutrophil count [ANC] at least 1,500/mm ) during this period, WBC counts may be monitored every other week thereafter. After the discontinuation of clozapine, continue weekly WBC counts for an additional 4 weeks. 

---