Systemic Toxicity from Ocular Homatropine

Abstract

Toxidromes are well known to emergency physicians. An unclear or incomplete history and subtle findings on physical examination make the diagnosis of poisonings challenging. This article reports a patient who had an acute onset of visual hallucinations, pressured speech, and mania. Although she denied taking any medications, she was ultimately diagnosed as having anticholinergic toxicity. On further questioning of family members, it was discovered that she was being treated for anterior uveitis with 5% homatropine. This case illustrates the potential role of ocular medications in systemic toxicity. Patients often do not consider eyedrops to be medications, and their use may be overlooked in the medical history. It also is important to educate patients and medical staff in methods to minimize systemic toxicity when using ocular medication.Key words: anticholinergic toxicity; ophthalmic medications; drug-induced toxicity; homatropine. I Toxicity related to anticholinergic agents is well known. Although toxidromes are often caused by medicines administered orally, it is important to remember that ocularly applied drugs can cause toxicity as well. We report a case of anticholinergic poisoning from ocular application of homatropine for the purpose of illustrating the potential role of ocular medications in producing systemic toxicity and to emphasize means to minimize systemic toxicity when using these agents. The patient was a 55-year-old Polish cleaning woman who presented to the Albany Medical Center ED with an acute onset of agitation, paranoid ideation, and pressured speech. According to her husband, the patient returned from her job "speaking wildly" and "afraid [that] people were after her." Later that evening she thought she saw herself performing on television, then claimed to be followed by men. The following day florid visual hallucinations ensued concerning "bloody babies" and "piles of money." Her past medical history included possible hypertension, but the husband noted In the ED, the patient was pacing the hallway and shouting in Polish to her husband and other patients near her. Her only discernible English words were "I not crazy" and "Mario Cuomo." The vital signs were: oral temperature 38.2"C (100.8"F), blood pressure 170/100 mm Hg, pulse 100 beats/min, and respiratory rate 20 breathdmin. Her skin and mucous membranes were flushed and dry. The pupils were reactive to light and dilated (more so on the left). Funduscopic examination revealed sharp disk margins. No hernotympanum was found. The neck was supple and no adenopathy was palpable. The lungs were clear and the cardiac examination revealed a regular tachycardia at a rate of 100 beatshin. The abdomen was distended and slightly tympanitic with diminished bowel sounds. The neurologic examination showed intact cranial nerves 2-12. The upper extremities and lower extremities were of equal 5/5 motor strengths. Sensation was intact to light touch and pinprick. Deep tendon reflexes were not obtainable secondary to agitation.Laboratory studies...

Pretreating Rats with Parenteral Ophthalmic Antimuscarinic Agents Decreases Mortality from Lethal Organophosphate Poisoning

“…11 One case report describes classic systemic antimuscarinic poisoning after ophthalmic administration of homatropine for the treatment of anterior uveitis. 12 In choosing a dose of homatropine for study, we found that doubling the dose of homatropine (20 mg/kg vs. 10 mg/kg of atropine sulfate) was equivalent to standard atropine sulfate in preventing death in our previous work in the laboratory as well as in this current experiment. 8 Our study revealed a significant survival benefit for rats treated with standard atropine sulfate (10 mg/kg), ophthalmic homatropine (20 mg/kg), and ophthalmic atropine sulfate (10 mg/kg).…”

Uncontrolled Agitation and Flushed Face Due to Tropicamide: A Missed Diagnosis

“…Cases of anticholinergic poisoning following the administration of topical eye drops containing atropine or atropine-like substances have been previously reported (1,(3)(4)(5). When a patient has nonreactive dilated pupils, tachycardia, flushed skin, dry mucosa, hyperthermia, urinary retention, and changes in consciousness, anticholinergic poisoning should be considered (3,4,6). Decreased sweat levels, reduction in bowel sounds, visual and auditory hallucinations, delirium, seizures, coma, and even death may also represent part of the anticholinergic toxidrome (Table 1) (6).…”

Intramuscular ophthalmic homatropine vs. atropine to prevent lethality in rates with dichlorvos poisoning

“…In order to obtain similar results in our study, the homatropine dosing requirement was twice that of atropine. Classic antimuscarinic poisoning has been reported with systemic poisoning of homatropine after ophthalmic administration for the treatment of anterior uveitis [14].…”