title: Lactulose-associated lithium toxicity: a case series.
abstract: BACKGROUND
  Lactulose is commonly used for constipation and hepatic encephalopathy. Its adverse effects of dehydration and serum electrolyte imbalances are widely known.
  
  
  OBJECTIVE
  This study aimed to describe a case series of 3 patients receiving lactulose who developed lithium toxicity.
  
  
  METHODS
  The authors described a case series of 3 patients admitted to a large county psychiatric hospital who developed lithium toxicity while taking lactulose for constipation or hyperammonemia.
  
  
  RESULTS
  In all 3 cases of lithium toxicity, the patients were prescribed with lithium for acute mania and lactulose for constipation or hyperammonemia. One case required the patient to be transferred to a local emergency department for further treatment.
  
  
  CONCLUSIONS
  This case series shows the interaction between lithium and lactulose. It is postulated that lactulose's effects of volume depletion can lead to poor renal excretion of lithium.
authors.affiliation: From the *Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California at Davis; and †Sacramento County Mental Health Treatment Center, Sacramento, CA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Bregman
authors.forename: Kathy
authors.initials: K
authors.lastname: Fritz
authors.forename: Glen L
authors.initials: GL
authors.lastname: Xiong
mesh_terms: D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects* / Q000097:blood; D003248:Constipation / Q000097:blood / Q000188:drug therapy; D004347:Drug Interactions / Q000502:physiology; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D007792:Lactulose / Q000008:administration & dosage* / Q000097:blood; D008094:Lithium / Q000008:administration & dosage* / Q000009:adverse effects* / Q000097:blood; D008297:Male; D008875:Middle Aged
chemical_list: D014150:Antipsychotic Agents; D005765:Gastrointestinal Agents; D007792:Lactulose; D008094:Lithium