nocturnal enuresis ( ne ) is defined as nighttime bedwetting after developmental age when bladder control should have been established . anatomical and functional integrity of noradrenaline , dopamine and serotonin systems is required for continence .
iatrogenic ne is an adverse event commonly reported in patients taking several central nervous system agents , in particular antipsychotics , ( risperidone and clozapine ) , ssri and some antiepileptics ( sodium valproate ) . despite enuresis
being reported as a very rare adverse event in summary of product characteristics of some antihistamines , no single case report is available to date in literature .
we herein report a case of a child presenting with ne after treatment with the antihistamine drug cetirizine .
a 6-year - old female child presented with recurrent episodes of rhinitis , bronchitis and bronchospasm since the age of 2 years . her family history was positive for allergic diatheses .
the rest of her past medical history was unremarkable with normal developmental milestones having been reached .
she never experienced episodes of ne after bladder control was achieved at the age of 3 years . during an episode of persistent dry coughing , which was unresponsive to oral betamethasone 1 mg / day ,
she was prescribed add - on oral cetirizine 5 mg / day in the evening for a week . on day
two months later , she was again treated with oral cetirizine at the same dosage for another episode of cough and bronchospasm .
a total score of 9 ( probable ) was obtained on the naranjo causality scale .
in particular , a subtle regulation between noradrenaline , serotonin and dopamine pathways is required for appropriate bladder control .
functional imbalance of these neurotransmitters within basal ganglion structures appears to be central in the pathophysiology of enuresis and urinary incontinence .
the substantial role of dopaminergic circuits is supported by the frequent neurogenic detrusor overactivity and voiding dysfunction in patients with parkinson 's disease or other extrapyramidal dysfunctions , due to nigrostriatal dopamine depletion .
noradrenergic and serotoninergic systems exert their effects on continence directly , but also by facilitating or inhibiting dopaminergic pathways , respectively .
overall , pharmacological agents depleting or blocking norepinephrine or dopamine cause incontinence or enuresis , while drugs increasing these pathways induce urinary retention [ table 1 ] .
experimental studies proved that the histaminergic system directly influences the serotonin transmission in the central nervous system , by the presynaptic inhibition of 5-hydroxytryptamine release .
therefore , antihistamine treatment , acting on 5-hydroxytryptamine regulation , could involve a central serotonin disinhibition , leading to an imbalance of the serotonin / dopamine ratio .
drugs reported to be associated with enuresis in particular , cetirizine in this patient could have enhanced serotonin pathways originating from raphe nucleus , which exert an inhibitory effect on dopamine release from the mesocortical tract .
thus , this disrupted serotonin modulation can lead to a relative dopaminergic depletion , which eventually causes enuresis .
 nocturnal enuresis is a common disorder in childhood , but its pathophysiological mechanisms have not been fully elucidated . 
 iatrogenic nocturnal enuresis has been described following treatment with several psychotropic medications . 
 herein , we describe a 6-year - old child who experienced nocturnal enuresis during treatment with the antihistamine cetirizine . 
 drug rechallenge was positive . 
 several neurotransmitters are implicated in the pathogenesis of nocturnal enuresis , including noradrenaline , serotonin and dopamine . 
 antihistamine treatment may provoke functional imbalance of these pathways resulting in incontinence . 
Introduction
Case Report
Discussion