this is an unusual case of a 42-year - old gentleman , admitted to the intensive treatment unit ( itu ) following an attempted suicide .
he was observed to develop significant polyuria following admission to itu and this polyuria resolved when propofol was stopped with no further treatment .
this is a rare occurrence of this side effect with this drug , considering how frequently it is used
. it may be the case that it occurs more frequently than is known about at present since it may be under - reported , which is why we feel this case report and the discussion it may stimulate are important .
a 42-year - old man with a known psychiatric history was admitted in the morning to itu for respiratory and circulatory support following a mixed overdose .
he had taken 50 mg of ramipril , 150 mg of olanzapine , and 200 mg of citalopram .
he had taken no alcohol , paracetamol , aspirin , or recreational drugs and had not suffered any head injury .
on itu he was sedated with 120 mg / h infusion of propofol 1% . in the afternoon
, he was noted to be polyuric with a urine output greater than 500 ml / h and his urine was noted to be progressively more dilute [ figure 1 ] .
catheter bag showing progressively more dilute urine since admission urine and serum osmolarity were measured .
the following morning , sedation was stopped and he was extubated successfully . shortly thereafter , urine concentration returned to normal .
medline was used to perform searches with combinations of the term  diabetes insipidus  and the drugs taken in overdose .
there were no results found for a medline search of  ramipril  and  diabetes insipidus  or
 citalopram  and  diabetes insipidus .  the search  diabetes insipidus  and  olanzapine  gave three results : one case report detailing the case of a 17-year - old who had taken an overdose of olanzapine and developed cranial diabetes insipidus whilst in itu ; a case report of a patient treated for diabetes insipidus secondary to lithium in a patient also taking olanzapine ; and a pilot study of the use of olanzapine in a palliative care setting in which one of the 24 patients developed diabetes insipidus .
olanzapine is well absorbed via the oral route and its half - life is approximately 33 h , making it highly unlikely to be the culprit in our case where the polyuria resolved completely less than 36 h following ingestion of the overdose .
on reviewing the notes , it was found that the resolution of the polyuria seemed to occur shortly after sedation with propofol was stopped
. a further search of  diabetes insipidus  and  propofol  was performed .
this found one case report linking the use of propofol as an anesthetic with diabetes insipidus .
the mechanism of action of propofol ( 2 , 6-diisopropylphenol ) as an anesthetic is not fully understood , but it enhances gaba ( gamma - aminobutyric acid)-mediated inhibition of adh ( anti - diuretic hormone / arginine vasopressin ) release in rats , which is a potential mechanism for transient neurogenic diabetes insipidus in humans .
the onset of the action of propofol is 30 s and its action is short - lived .
the case report linking olanzapine and diabetes insipidus does not state what sedation was used whilst the patient was on itu .
this case report shows that it is possible for propofol to induce polyuria in humans as it does in animal studies .
why this does not occur more frequently , given how commonly propofol is used in the itu setting , is unclear and should be the subject of further investigation .
it is possible that the use of other drugs in conjunction with propofol may have led to the under - recognition of the association with propofol .
propofol is often used for the induction of anesthesia rather than maintenance , so polyuria may be less pronounced with smaller doses , attributed to other drugs or to the administration of iv fluids intra - operatively .
 case report detailing the occurrence of diabetes insipidus in a 42-year - old man admitted to the intensive treatment unit ( itu ) following an overdose . 
 whilst on itu , he was sedated with propofol . 
 cessation of treatment with propofol coincided with resolution of the polyuria . 
 animal studies suggest a theoretical mechanism for propofol as the causative agent , but this phenomenon is not commonly seen in humans . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONCLUSION