Guidance was recently updated on the clozapine REMS website (click on Important Program Update as of 4/02/2020) which states, “If you become aware or your patients report concerns in obtaining an ANC during this public health emergency, consider whether there are compelling reasons not to obtain an ANC and use your best medical judgment weighing the benefits and risks of continuing treatment in the absence of laboratory testing. Communicate with your patients regarding these judgments, including the risks associated with it.”
In March 2020, the FDA offered the following guidance for the REMS program:
Since there is not specific guidance from REMS or FDA, clinicians prescribing clozapine should weigh the potential risks and benefits of Absolute Neutrophil Count (ANC) in individual patients. These should be discussed with patients, and there should be an informed consent discussion with any changes in testing. There are likely to be patients for whom risks related to contracting COVID while getting blood drawn are higher than the risk of not having an ANC test. In evaluating risks, clinicians can include consideration of the following: About two thirds of cases of severe neutropenia occur during the first three months of exposure to clozapine. About one tenth occur between four and six months. The rest occur at a low rate after that period. While risk factors for serious COVID related complications are not yet fully defined, risk appears increased with older age, concurrent medical problems, immunosuppression, and pulmonary problems. With regard to serious mental illness, note that this population may be at increased risk for chronic obstructive pulmonary disease, asthma, obesity and diabetes; and rates of smoking are very high.