Neurotoxic effects induced by the topical administration of cycloplegics

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Neurotoxic effects induced by the topical administration of cycloplegics in a pediatric patient

V. Saavedra, C. Folguera, A. Torralba
Universitary Hospital Puerta de Hierro, Pharmacy, Madrid, Spain

Background; Cycloplegic drugs are frequently used in ophthalmology examinations. Although they are administered topically, their absorption could produce neurotoxicity.

Purpose:To report the risk of neurotoxicity associated with cycloplegic eye drops.

Material and Methods: Review of the available literature about neurotoxicity and cycloplegic eye drops, and report of a case that happened in the Paediatric Department during the pharmacist training period.

Results: A 4-year-old girl was admitted to the Emergency Department presenting a confusional episode with incoherent speech, unresponsive bilateral mydriasis, agitation, unsteady gait, visual hallucinations, spatial disorientation and lack of recognition of her family. Her parents revealed that two hours before an ophthalmologist had administered to her one drop of tropicamide and one drop of cyclopentolate eye drops for a fundus examination. The patient was admitted and was kept under observation, considering that the half-life of these eye drops is around 6 h for tropicamide and 24 h for cyclopentolate. During the first 24 h the patient evolved favourably. No drugs were administered to resolve the clinical status. The neurotoxicity was resolved progressively although nonreactive bilateral mydriasis persisted 3 days after intoxication. This case was reported to Madrid’s Pharmacovigilance Centre, which replied that these side effects are described for these drugs: they are dose dependent, and if administration is not stopped there could be risk of coma with cardiovascular collapse, even death. A review carried out about the neurotoxic effect of these drugs reported 75 cases of neurotoxicity in patients exposed to cycloplegic drugs: 29 cases were due to cyclopentolate, 19 to atropine, 18 to homatropine, 7 to scopolamine and 2 to tropicamide. Many of the patients reported were children or elderly people.

Conclusion: Topical administration of drugs must not be underestimated. In our patient the neurotoxicity was resolved without sequelae but some cases of death have been reported. Moreover, neurotoxicity induced by cycloplegic drugs should be considered in order to make a differential diagnosis of acute confusional syndromes.

Reference: 16th Congress of EAHP. 30 March - 01 April 2011. Viena. Austria