From the Department of Pediatrics, Base Hospital, Delhi Cantonment, Delhi 110 010, India.
Reprint requests: Dr. S.S. Bhatia, Lt. Col, AMC, Department of Pediatrics, Base Hospital, Delhi Cantonment, Delhi 110 010, India.

Manuscript Received: July 28, 1999;
Initial review completed: September 8, 1999;
Revision Accepted: September 15, 1999

Cyclopentolate is a commonly used cycloplegic and mydriatic. Systemic toxicity in the form of atropine like effects, is rare in practice(1). We report two cases of systemic toxicity following cyclopentolate eye drops. Though the reactions were transient they can be alarming to the patient and doctor.

Case 1: An 8-year-old girl who was undergoing ophthalmoscopic examination for refraction was administered cyclopentolate hydrochloride (1%) eye drops, 2 drops in each eye. Within 15 minutes she started feeling uncomfortable, and could not recognize her mother. She started behaving abnormally within half-hour after the instillation with delusions and hallucinations. She complained of crawling insects and seeing objects that were not there. Her speech was inappropriate and irrelevant. She also had marked flushing of face and extremities, hot and dry skin and retention of urine. Her pulse rate was 106/minute. Her pupils were dilated and sluggishly reacting to light. Her eyes were thoroughly washed with water. Recovery was spontaneous within 8 hours. The pupils remained dilated for three days.

Case 2: This 3½-year-old male child was administered cyclopentolate (1%) eye drops two drops in each eye for fundus examination for ophthalmologic screening. Within one hour he developed fever, redness of the face and limbs and abnormal behavior. He started picking objects from his skin. His speech was irrelevant. His pulse rate was 124/minute. The pupils were dilated and not reacting to light. His eyes were washed with water and he was given diazepam syrup as a sedative. He recovered the next day. However, the mydriasis and cycloplegia persisted for 4 days.

Cyclopentolate is a commonly used cycloplegic in pediatric practice for refraction testing. Cyclopentolate is a synthetic anti-cholinergic which produces mydriasis and cycloplegia. It has the advantages of rapid onset of action and recovery with an adequate depth of cycloplegia. Side effects though uncommon can occur and produce symptoms of anti-cholinergic toxicity(1). In view of the smaller body mass in children, the chances of toxicity are higher. Systemic absorption can occur trans-conjunctivally or through the nasolacrimal duct(2).

The adverse reactions include transient stinging sensation and hyperemia, which occurs on instillation. An increase in intraocular pressure can occur which, may precipitate glaucoma in patients with narrow anterior chambers. Systemic toxicity is dose related and occurs with repeated instillation of 1% solution. Preterm, severely ill, are more prone to toxicity. Females, fair children and children with Down’s syndrome are also more prone to toxicity. This probably explains the earlier onset of symptoms in Case 1. The toxicity includes inappropriate behavior, changes in emotional attitude, hallucinations both visual and auditory and cerebellar signs(1,3-7). Rarely generalized seizures can occur(1). The CNS toxicity is due to anticholinergic action causing stimulation of the medulla and cerebral centres. They normally occur within 20-30 minutes of administration and subside within 4-6 hours with no perma-nent sequelae, with the patients having no recollection of the hallucinations. Another possible reason for the hallucinations could be the similarity of cyclopentolate’s amino-dimethyl group to the amino-methyl group found in LSD (a hallucinogenic agent)(1,3). CNS toxicity is rare(1), though some studies have reported an incidence of pscyhosis as high as 4%(6).

The other systemic side effects include the atropine like effects ‘dry as a bone’ due to inhibition of sweat and salivary glands (one of the first effects) and ‘red as beet’ because of vasodilation to lose heat so as to overcome lack of function of the sweat glands. Rare allergic reactions include urticarial rash, headache, nausea and wheeze. Severe anapylactic reac-tions have also been reported(1).

Precautions to decrease the chances of adverse reactions include avoiding overdosage, punctal occlusion following application and avoiding high ambient temperature and humidity(1). The use of microdrops (5 mL) as compared to normal drops (35 mL) could also decrease the incidence of side effects(8). Use of diluted cyclopentolate, safer drugs like tropicamide or homatropine (2%) could be the other alternatives. Early recognition of signs and symptoms of systemic toxicity is essential. Treatment is essentially symptomatic, with physostigmine being reserved for serious toxicity(1,8). Parents should be warned of possibility of further reactions to medications that are inherently anticholinergic in nature.

1. Lyndon WJ, T Hodes DT. Possible allergic reactions to cyclopentolate hydrochloride: Case reports with literature review of uses and adverse reactions. Ophthalmic Physiol Opt 1991; 11: 16-21.

2. Palmer EA. How safe are ocular drugs in Pediatrics? Ophthalmology 1986; 93: 1038-1040.

3. Sato EH, de Feretas D, Foster CS. Abuse of cyclopentolate hydrochloride drops. N Eng J Med 1992; 326: 1363-1364.

4. Tripathi SK, Mondal TK. Systemic toxicity with cyclopentolate eye drop. J Indian Med Assoc 1990, 88: 266.

5. Awan KJ. Systemic toxicity of cyclopentolate hydrochloride following topical ocular instilla-tion. Ann Ophthalmol 1976; 8: 803-806.

6. Khurana AK, Ahluwalia BK, Choudhary R, Vohra AK. Acute psychosis associated with topical cyclopentolate hydrochloride. Am J Ophthalmol 1988; 105: 91.

7. Elibol O, Alcelik T, Yuksel N, Caglar Y. The influence of drop size of cyclopentolate, phenyl-ephrine and tropicamide on pupil dilatation and systemic side effects in infants. Acta Ophthalmol Scand 1997; 75: 178-180.

8. Gray LG. Avoiding adverse effects of cycloplegics in infants and children. J Am Optom Assoc 1979; 50: 465-470.