A Case Report of Cyclopentolate-induced Brief Psychotic Disorder in a Child with Mild Intellectual Disability

To the editor,

Cyclopentolate, an anticholinergic drug used as a cycloplegic agent in many ophthalmological practices, if systematically absorbed, can lead to psychosis. ¹ It can also lead to central anticholinergic syndrome, which can manifest as restlessness, tachycardia, hyperactivity, seizures, etc. ¹ Only a few case reports in the past have described psychosis following cyclopentolate use for pupillary dilation in children.^2,3 However, no such case has been described where a brief psychotic reaction developed in a child with an intellectual disability post-cyclopentolate drop use. In this case report, we describe one such case.

A 13-year-old male child with a personal history of delayed crying during birth and global delay in developmental milestones with an intelligence quotient of 60 without any history of major mental illness presented to the outpatient department with a history of abrupt onset following administration of multiple sequential cyclopentolate drops (one% w/v) in both eyes for a continuous course within one hour characterized by second-person auditory hallucinations, visual hallucinations, irritable mood, fearfulness, and decreased sleep, which persisted for around 30 hours (from around noon on the day of presentation to the evening of the second day). The ophthalmologist advised him to have a fundoscopy for a complaint of decreased vision for many months. He was initially instilled with two drops in each eye, and his parents were instructed to do the same every 15 minutes. However, his parents instilled more than two drops in each eye within a 10-minute gap, and his abnormal behavior was noted within an hour. On examination on the day of presentation, he had a heart rate of 88 beats per minute, a blood pressure of 110/60 mm Hg, a respiratory rate of 13 breaths per minute, and he was afebrile. Pallor, icterus, cyanosis, clubbing, lymphadenopathy, or edema was absent. On systemic examination, his neurological examination showed pupils were dilated and poorly reactive to light and accommodation, and no other focal neurological deficits were elicited. The respiratory, cardiovascular, gastrointestinal, and musculoskeletal examinations were within normal limits. On mental status examination, he was agitated. Second-person auditory hallucinations consisted of multiple voices commanding him to run away from the hospital. Visual hallucinations consisted of multiple distinct, colorful animals moving around him, and he was often seen pointing to them on the roof and walls. He was kept under close observation for around six hours without any psychotropic administration, as he was not aggressive, and the agitation reduced significantly within two hours of observation. The psychotic symptoms were also gradually reducing. He was followed up telephonically, and his parents reported that the symptoms were gradually decreasing. The psychotic symptoms continued until the second day (till around evening) but were not present when the child presented on the third day of the onset of symptoms. He scored seven (probable) on the Naranjo-adverse drug reaction probability scale ⁴ .

Cyclopentolate is a tertiary amine that functions similarly to atropine and is antimuscarinic and anticholinergic.^1–3 It is well absorbed both systemically and into the eye when applied topically, leading to a total or relative decrease in cholinergic activity in the brain, manifesting as psychosis.^1–3 Muscarinic receptor agonists have been shown to reduce psychotic symptoms in individuals with neuro-cognitive disorders. ⁵ Intellectual disability has been linked to muscarinic acetylcholine receptor dysfunction and downstream signaling pathways. ⁶ These, too, can explain the psychotic symptoms in our case. The duration of psychosis was longer as compared to previously described reports among children;^2,3 this may be due to existing intellectual disability and pharmacokinetic variation in our case.

Ophthalmologists and psychiatrists should be aware of rare but possible cyclopentolate-induced brief psychosis and consider appropriate preventive or corrective measures. Further studies must be conducted to explore the pathophysiology underlying this phenomenon.