acute pancreatitis due to antipsychotic treatment is rare but sometimes causes a fatal adverse effect .
some atypical antipsychotic agents , including clozapine , olanzapine , quetiapine , and risperidone , are associated with acute pancreatitis.1,2 ) among them , acute pancreatitis caused by risperidone is the rarest.3,4 ) although most cases of acute pancreatitis due to atypical antipsychotic agents occur within 6 months of starting antipsychotic administration,1 ) we experienced a schizophrenic patient suffering from pancreatitis after more than 6 months of risperidone therapy .
a 69-year - old japanese woman was diagnosed with schizophrenia at the age of 30 years and received outpatient care at another mental hospital .
her positive symptoms were not prominent , but her cognitive level was so impaired that she could not regulate her appetite and consumed about 2,000 kcal / day in addition to three ordinary meals .
she had never smoked , did not drink alcohol , and did not take any illegal drugs .
blood tests ( table 1 ) , abdominal ultrasonography , and a computed tomography ( ct ) scan were performed .
clinical features were accompanied by laboratory findings of hyperamylasemia ( amylase , 1,191 u / l ) , hyperlipasemia ( lipase , 1,514 u / l ) , and mild liver enzyme elevations .
results of the abdominal ultrasonography were positive for gallstones in the gallbladder and distention of the common bile duct .
subsequently , the amylase and lipase titers remained high ( 461 u / l and 804 u / l , respectively ) , although alanine and aspartate aminotransferases decreased gradually to normal levels .
at this point , we felt that it was safe for her to start taking the risperidone again .
two days after starting the risperidone , serum lipase and amylase increased again to 1,275 u / l and 745 u / l , respectively , and ck also increased ( 766 u / l ) .
we decided to suspend the risperidone and introduced 10 mg intravenous haloperidol injections once per day .
two days after discontinuing the risperidone , the serum amylase decreased ( 605 u / l ) , but the serum lipase level remained elevated ( 1,654 u / l ) .
one week after discontinuing the risperidone , the levels of amylase and lipase decreased gradually ( 309 u / l and 542 u / l , respectively ) , and ck dropped to the normal range .
as her general clinical condition and biochemical markers were stable , we changed the haloperidol injection to an oral solution of 6 mg / day aripiprazole because her mental condition worsened after stopping the risperidone treatment .
her mental status improved with the aripiprazole treatment , and she was discharged without positive laboratory findings .
the patient 's monthly blood tests continue to be normal , including amylase , lipase , and blood cell counts .
although atypical antipsychotic - induced pancreatitis has been reported in conjunction with hyperglycemia,5 ) the pathophysiological mechanism of these adverse events remains unclear .
most antipsychotic - induced pancreatitis occurs within 6 months after administration1 ) ; however , our case developed pancreatitis more than 6 months after the start of risperidone treatment .
risperidone is a 5-ht2a antagonist and ameliorates diet - induced necrotic pancreatitis in mice,6 ) and reduced serum pancreatic amylase levels is observed after endoscopic retrograde cholangiopancreatography.7 ) however , there is no evidence of an association between risperidone treatment and acute pancreatitis . a thorough evaluation for pancreatitis , such as alcohol , tumor , and autoimmune causes ,
gallstones were present , which were due to an adverse effect of risperidone because the two separate risperidone administrations elevated serum amylase and lipase independently .
aripiprazole is currently used in such cases , as aripiprazole is thought to have fewer effects on metabolism , including saccharometabolism , than other atypical antipsychotic agents . lifestyle was also a risk factor in this case .
thus , it is necessary to monitor pancreatic function in addition to hyperglycemia in such cases .
 acute pancreatitis with antipsychotic treatment is rare but sometimes causes a fatal adverse effect . 
 most cases of acute pancreatitis due to atypical antipsychotic agents are reported to occur within six months of starting antipsychotic administration . 
 acute pancreatitis caused by risperidone is rare . 
 the patient had a high fever , stomachache and vomiting . 
 the results of the abdominal computed tomograhpy scan were negative . 
 the results of the abdominal ultrasonography were positive for gallstones in gallbladder and distention of the common bile duct . 
 she had been fasting and received antibiotic intravenous injections . 
 amylase and lipase titers were high . 
 after risperidone discontinuation , both the levels of the amylase and the lipase were gradually decreased . 
 three months later , the patient still maintains a good clinical balance . 
 although atypical antipsychotic - induced pancreatitis has been reported in conjunction with hyperglycemia , the pathophysiologic mechanism of these adverse events remains unclear . 
 this case got pancreatitis 6 month after risperidone treatment . using the antipsychotic agents , it is necessary to monitor pancreas function . 
INTRODUCTION
CASE
DISCUSSION