Asymptomatic pancreatitis associated with clozapine

Besides the well-known adverse effects of clozapine, such as granulocytopenia, tiredness and hypersalivation, acute pancreatitis is known to be a very rare complication of the drug. In the literature a total of five case reports have been published so far. We report a case of asymptomatic pancreatitis subsequent to clozapine treatment at therapeutic doses in a 38-year-old male patient with chronic paranoid-hallucinatory schizophrenia. The patient was rehospitalized after an acute exacerbation of the psychosis subsequent to an attempt to change medication on an outpatient basis. Treatment with clozapine was initiated again. During phases of progressively increasing the clozapine dose, serum levels of amylase and lipase were increased; after maintaining daily doses of clozapine of 300 mg and/or 600 mg the pancreatic enzymes normalized quickly within a few days. The patient did not report any pancreas-related complaints, nor did specific diagnostic studies produce any indicative result, only a minor thickening of the head and body of the pancreas in the ultrasound. It is assumed that the phenomenon of subclinical, asymptomatic pancreatitis during increasing dosage of clozapine occurs more often than previously supposed. The monitoring of serum amylase levels during slow increase in clozapine is recommended; if leukocytosis or eosinophilia is present, the possibility of even a subclinical and asymptomatic pancreatitis should be considered.