This information is sourced from the Specialist Pharmacy Service and the RCPsych:

If a patient on clozapine describes symptoms suggestive of Covid-19, be aware that similar symptoms can arise from other incidental infections associated with neutropenia.

For patients on clozapine with Covid-19 symptoms recommendations are:

• Continue clozapine but take a blood sample immediately to determine WCC; neutrophil count; and clozapine plasma concentration
• If the patient is suspected of having a serious clozapine-related ADE (adverse drug effects) then stop clozapine and investigate appropriately

Symptoms of Covid-19 can mimic clozapine related ADEs: notably, myocarditis and neutropenic sepsis:

• Myocarditis: clozapine related myocarditis is more likely to occur within the first 6 weeks of treatment. Therefore after the initial period, the likelihood of any myocarditis being clozapine related reduces

• White cell count: Covid-19 can cause a reduction in white cell count but does not appear to affect neutrophil levels, whilst clozapine does. Therefore if neutrophil levels are stable, continue clozapine

See further advice: Covid-19 and Clozapine