K Raaska1, V Raitasuo, P J Neuvonen. 1. Department of Clinical Pharmacology, University of Helsinki, Finland. kari.raaska@hus.fi
Abstract
OBJECTIVE: To study the effect of influenza vaccine on serum clozapine, N-desmethylclozapine and clozapine-N-oxide steady-state concentrations in patients with schizophrenia. METHODS: This was an open-label study in 14 schizophrenic inpatients (with 2 drop-outs) using clozapine. Serum trough concentrations of clozapine. N-desmethylclozapine and clozapine-N-oxide, as well as the concentration of c-reactive protein (CRP), were measured immediately before conventional trivalent influenza vaccination and 2, 4, 7 and 14 days after the vaccination. RESULTS: Influenza vaccination had no significant effect on serum concentrations of clozapine, N-desmethylclozapine or clozapine-N-oxide. No changes in the clinical effects of clozapine were observed after vaccination. Influenza vaccination did not increase CRP. However, two drop-out patients who developed upper respiratory and abdominal symptoms had increased and elevated serum concentrations of clozapine, compared with the baseline. CONCLUSIONS: Influenza vaccination using conventional trivalent influenza vaccine does not affect serum concentrations of clozapine or its main metabolites. However, an infection-related increase in CRP may be associated with increased serum concentration of clozapine.
OBJECTIVE: To study the effect of influenza vaccine on serum clozapine, N-desmethylclozapine and clozapine-N-oxide steady-state concentrations in patients with schizophrenia. METHODS: This was an open-label study in 14 schizophrenic inpatients (with 2 drop-outs) using clozapine. Serum trough concentrations of clozapine. N-desmethylclozapine and clozapine-N-oxide, as well as the concentration of c-reactive protein (CRP), were measured immediately before conventional trivalent influenza vaccination and 2, 4, 7 and 14 days after the vaccination. RESULTS: Influenza vaccination had no significant effect on serum concentrations of clozapine, N-desmethylclozapine or clozapine-N-oxide. No changes in the clinical effects of clozapine were observed after vaccination. Influenza vaccination did not increase CRP. However, two drop-out patients who developed upper respiratory and abdominal symptoms had increased and elevated serum concentrations of clozapine, compared with the baseline. CONCLUSIONS: Influenza vaccination using conventional trivalent influenza vaccine does not affect serum concentrations of clozapine or its main metabolites. However, an infection-related increase in CRP may be associated with increased serum concentration of clozapine.
Authors: Selene R T Veerman; Timo Moscou; Jan P A M Bogers; Dan Cohen; Peter F J Schulte Journal: Acta Psychiatr Scand Date: 2022-04-01 Impact factor: 7.734