Clotiapine Monotherapy in a Patient With Clozapine-Resistant Schizophrenia
Randomized trials have shown that, on average, clozapine is more effective than other antipsychotics in treating patients with schizophrenia who have responded poorly to prior antipsychotic trials.1,2 However, several adverse effects, such as agranulocytosis, myocarditis, metabolic syndrome, insulin resistance, and diabetes mellitus, limit clozapine use. Patients taking clozapine should receive routine weekly to monthly monitoring and maintain a white blood count 3500/μL or greater and an absolute neutrophil count ≥2000/μL. When severe adverse effects occur, it is highly suggested to discontinue taking clozapine immediately and switch it to other antipsychotics if necessary.
Clotiapine (Etumine) is a typical antipsychotic among the dibenzothiazepine chemical class. It was first introduced to a few European countries (namely, Belgium, Italy, Spain, and Switzerland), Argentina, Taiwan, and Israel in 1970. Clotiapine has a chemical structure similar to clozapine and was also reported with possible clozapine-like properties. Although clinical evidence from randomized controlled trials is limited, it was said that patients unresponsive to other neuroleptics respond to clotiapine, although it may cause extrapyramidal syndromes like other typical neuroleptics3 can. However, whether clozapine can be successfully switched to clotiapine remains unknown. The following case expatiates on a patient with long-lasting clozapine-resistant schizophrenia who responded well to clotiapine monotherapy.