Adrenoceptor agonist poisoning after accidental oral ingestion of brimonidine eye drops

Systemic toxicity from subcutaneous brimonidine injection successfully treated with naloxone: A case report

Brimonidine is a topical ophthalmic alpha-2 adrenergic agonist solution used to treat glaucoma. The toxidrome includes drowsiness, lethargy, hypotension, bradycardia, and respiratory depression when ingested in infants. We report a case of intentional subcutaneous injection of brimonidine in an elderly patient resulting in hypotension and CNS depression that responded to naloxone. A 73-year-old female with a past medical history significant for glaucoma, hypertension, and indwelling pacemaker presented to the emergency department after injecting her brimonidine tartrate ophthalmic solution subcutaneously (SQ). The patient was not taking any antihypertensive medications or opioids. Initial presentation consisted of lethargy, a paced rhythm of 60 bpm, and blood pressure of 91/24 mmHg with a MAP of 46. Due to central nervous system depression, 3 mg of intranasal naloxone was administered. The patient was treated with intravenous fluids and escalating doses of naloxone and required a continuous infusion. Mental status and vital signs subsequently improved. The patient was admitted to the ICU and naloxone was subsequently weaned over 12 h. Systemic central alpha-2 adrenergic agonist toxicity resulted from SQ brimonidine injection. Central alpha-2 adrenergic agonist overdoses present as sympatholytic effects including CNS depression, bradycardia, hypotension, and may mimic the opioid toxidrome. Brimonidine SQ injection has not previously been reported and this case has similar findings to other central alpha-2 adrenergic agonist poisonings. Naloxone has previously shown variable reversal of CNS depression in central alpha-2 overdose. In this case, high-dose naloxone was useful for reversing CNS depression and hemodynamic instability.

Potential of Stimuli-Responsive In Situ Gel System for Sustained Ocular Drug Delivery: Recent Progress and Contemporary Research

Eyesight is one of the most well-deserved blessings, amid all the five senses in the human body. It captures the raw signals from the outside world to create detailed visual images, granting the ability to witness and gain knowledge about the world. Eyes are exposed directly to the external environment; they are susceptible to the vicissitudes of diseases. The World Health Organization has predicted that the number of individuals affected by eye diseases will rise enormously in the next decades. However, the physical barriers of the eyes and the problems associated with conventional ocular formulations are significant challenges in ophthalmic drug development. This has generated the demand for a sustained ocular drug delivery system, which serves to deliver effective drug concentration at a reduced frequency for consistent therapeutic effect and better patient treatment adherence. Recent advancement in pharmaceutical dosage design has demonstrated that a stimuli-responsive in situ gel system exhibits the favorable characteristics for providing sustained ocular drug delivery and enhanced ocular bioavailability. Stimuli-responsive in situ gels undergo a phase transition (solution-gelation) in response to the ocular environmental temperature, pH, and ions. These stimuli transform the formulation into a gel at the cul de sac to overcome the shortcomings of conventional eye drops, such as rapid nasolacrimal drainage and short contact time with the ocular surface This review highlights the recent successful research outcomes of stimuli-responsive in situ gelling systems in treating in vivo models with glaucoma and various ocular infections. Additionally, it also presents the mechanism, recent development, and safety considerations of stimuli-sensitive in situ gel as the potential sustained ocular delivery system for treating common eye disorders.

Adverse effects of brimonidine eye drop in children: A case series

WHAT IS KNOWN AND OBJECTIVE

Brimonidine is increasingly used in the treatment of intraocular hypertension.

CASE SUMMARY

We report on five paediatric patients suffering from brimonidine eye drop intoxication. The most frequent signs of the intoxication were a lowered level of consciousness and hypotonia. Other complications were apnea, bradycardia, hypotension and seizure. One of the patients needed cardiopulmonary resuscitation. Apnea in one of the cases was resistant to naloxone. Pupils were unremarkable in two cases.

WHAT IS NEW AND CONCLUSION

Brimonidine is potentially lethal for young infants. The absence of miosis and absence of response to naloxone is not a reason to rule out brimonidine poisoning.

A review of neuropsychiatric adverse events from topical ophthalmic brimonidine

Brimonidine is a first-line topical medication for increased intraocular pressure and glaucoma which may be used alone or in conjunction with other topical therapies. Its structural and pharmacological comparabilities to clonidine give way to the hypothesis that it may cause neuropsychiatric side effects. The majority of case reports citing brimonidine toxicity, either for topical or peripheral exposure, include pediatric age groups but especially infants. Among the latter, a dose-response phenomenon is evident. Dose-response correlates have also been shown among adults. Case series and prospective double-blind treatment studies also give evidence for the occurrence of several central nervous system adverse reactions. Topical ophthalmic brimonidine use should be followed for the occurrence of neuropsychiatric disturbances generally, and enhanced vigilance should be maintained for at-risk populations.

Respiratuvar depression after accidental nasal ingestion of brimonidine eye drops in infant

OBJECTIVES

Brimonidine tartrate is an alpha-2 agonist used for glaucoma treatment. It can lead to serious poisoning symptoms when misused by children.

CASE REPORT

In this case report, 3 months-old male patient with severe central nervous system depression and respiratory arrest as a result of accidentally nasal instillation of 1 cc brimonidine tartrate that benefited from mechanic ventilation and naloxone treatment was presented.

CONCLUSION

This case report suggested, that misuse of nasal brimonidine eye drop could result in serious respiratory distress and central nervous system depression. Mechanical ventilation and naloxone administration can be useful for these patients.

Cardiotoxicodynamics: Toxicity of Cardiovascular Xenobiotics

Maintaining adequate tissue perfusion depends on a variety of factors, all of which can be influenced by xenobiotics (substances foreign to the body, including pharmaceuticals, chemicals, and natural compounds). Volume status, systemic vascular resistance, myocardial contractility, and cardiac rhythm all play a significant role in ensuring hemodynamic stability and proper cardiovascular function. Direct effects on the nervous system, the vasculature, or the heart itself as well as indirect metabolic effects may play a significant role in the development of cardiotoxicity. This article is dedicated to discussion of the disruption of cardiovascular physiology by xenobiotics.

Brimonidine tartrate poisoning in children: frequency, trends, and use of naloxone as an antidote

BACKGROUND

Brimonidine tartrate, a centrally acting selective alpha-2 adrenergic agonist with a toxicity that is often compared with that of clonidine, is used as eye drops to lower intraocular pressure in glaucoma. We investigated characteristics of childhood exposures to brimonidine-containing products.

METHODS

All brimonidine exposures in children 0 to 5 years of age between 1997 and 2005 were retrieved from the American Association of Poison Control Centers' Toxic Exposure Surveillance System database and the US Food and Drug Administration's Medwatch Adverse Events Reporting System. The design of the study was retrospective, and the main outcome measures were frequency of exposures over time, reason, symptoms/signs of toxicity, dose, management site, treatment, and outcome.

RESULTS

There were 413 brimonidine reports in the Toxic Exposure Surveillance System and 340 in the Adverse Events Reporting System during the 9 years under study, of which 185 Toxic Exposure Surveillance System reports involved children < or =5 years of age versus 15 cases in the Adverse Events Reporting System. There were no deaths. The peak age of poisoning in the Toxic Exposure Surveillance System pediatric cases was 2 years of age, and circumstances were unintentional poisoning in 176 cases, usually by ingestion (84.3%). Common symptoms in 176 children included drowsiness (40.9%), ataxia (4.5%), pallor (4.5%), irritability (4.0%), hypotension (4.0%), bradycardia (4.0%), miosis (3.4%), and respiratory depression (3.4%). Of the 176 unintentional pediatric poisonings, 73 children were observed at home and 103 were seen at a health care facility; 28 were hospitalized and 11 received naloxone. Of the 15 pediatric cases in the Adverse Events Reporting System data set, all were hospitalized, and 13 had ocular exposures only.

CONCLUSIONS

All children < or =5 years of age with confirmed brimonidine ingestions should be medically evaluated and monitored for an extended period. Indications for the use of naloxone in brimonidine poisoning remain uncertain.

Central alpha-2 adrenergic eye drops: case series of 3 pediatric systemic poisonings

Three pediatric patients presented with systemic central alpha-2 agonist poisoning-2 cases of bradycardia and apnea resulting from ingestion of ingestion of apraclonidine, with 1 case requiring intubation, and 1 case of bradycardia and altered mental status requiring intensive care monitoring resulting from therapeutic ophthalmic application of brimonidine. Pediatric poisonings involving central alpha-2 adrenergic agonists have been well described, particularly with the prototypical agent clonidine. Characteristic symptoms include sympatholytic effects such as central nervous system depression, respiratory depression, hypotension, bradycardia, miosis, hypothermia, and hyporeflexia. Although structurally similar to clonidine, these compounds are presumed to be safer for pediatric use because they are more polar and less lipophilic than clonidine, thereby limiting their ability to cross the blood-brain barrier and reducing incidence of centrally mediated effects. Systemic toxicities of alpha-2 agonist ophthalmic preparations in pediatric patients are similar to those seen with clonidine poisonings. Symptomatic patients should be treated in the same manner as patients with clonidine poisoning. Treatment of systemic poisoning is primarily supportive. Periodic tactile stimulation seems to be an effective nonpharmacological intervention to improve alpha-2 adrenergic agonist-induced central nervous system depression and respiratory depression. Intubation should be considered when tactile stimulation is not effective.

Unintentional ingestion of brimonidine antiglaucoma drops: a case report and review of the literature

A previously healthy, 1-year 7-month-old boy was brought to the emergency department after having unintentionally ingested topical brimonidine antiglaucoma drops. He was pale and lethargic and had brief periods of apnea and bradycardia. Activated charcoal was administered, and supportive measures were initiated, achieving complete resolution of the symptoms 4 hours after admission. Brimonidine poisoning is very rare, and a high index of suspicion is necessary to identify its signs and symptoms in the pediatric emergency department. To our knowledge, only 1 case of brimonidine poisoning after oral ingestion of this topical drug has been previously reported in the literature.