Naphazoline intoxication in children

Abstract

Inappropriate use or unintentional ingestion of naphazoline, especially in children, can quickly cause severe central nervous system depression and cardiovascular adverse effects [2,6].A five-year-old boy arrived at the Emergency Room 90 min after the ingestion of approximately 10 ml of Euboral Oftálmico solution (9.7 g of sodium-tetraborate, 0.1 g of naphazoline-chlorhydrate and 0.2 g of methylparaben for 1 l dilution, for topical use), prepared in a bottle without a label in a 0.02% concentration, which was twice that of the manufacturer's recommendation. During the physical examination, bradycardia (heart rate 45-50 bpm), hypothermia (35.5°C) and a blood pressure of 100/ 70 mmHg (blood pressure percentile 75th/90th) were observed. Gastric lavage and activated carbon administration were performed. A few minutes later, the patient presented somnolence, sweating, persistence of the bradycardia and hypothermia. Blood pressure and oxygen saturation were normal. At the EKG (electrocardiogram), sinusal bradycardia of 48 bpm was observed and laboratory parameters showed no abnormalities. Blood analysis of standard toxicological drugs was performed with negative results.Infusion therapy was started to force diuresis and the patient was admitted to the hospital in order to monitor vital parameters. Bradycardia lowest value (47 bpm) was observed 3 h after the ingestion. Somnolence and hypothermia (35.2°C) were maximum 7 h after the ingestion and sweating persisted until 12 h later. Blood pressure also returned to normal during this period without treatment; its highest value was 130/80 mmHg (blood pressure percentile >99th/99th) with no subsequent hypotension. The patient was discharged 20 h later.Naphazoline has a narrow therapeutic to toxic window and intoxication may occur at a dose of 0.05 mg/kg body weight [2]. Systemic side effects are observed rarely, despite frequent and uncontrolled use because of partial availability without doctor's prescription. They can progress potentially up to intoxication with vitally threatening cardiovascular symptoms (arterial hypertension with reflex bradycardia defined as a heart rate under 60 bpm and possible ischaemia of vital functions), pulmonary and central nervous symptoms. The central nervous system effects concern the reduction of vigilance ranging from drowsiness to coma, persisting cardiovascular hypotension and reduced respiration rate up to the Cheyne-Stokes breathing and possible pulmonary edema, hypothermia, mydriasis, hyperhydrosis and transient excitation hyperreflexia [1]. Our patient presented a large number of the symptoms described above, especially those affecting cardiovascular and central nervous systems. Blood analysis of standard toxicological drugs excluded alternative causes of intoxication.Because of rapid absorption, we wonder whether gastric lavage and carbon-activated administration are the suitable Eur J Pediatr (2006) 165:815-816

Intoxicación grave con nafazolina: puesta al día a partir de un error terapéutico

“…2 El vaciamiento gástrico y la administración de carbón activado no están indicados en los casos de ingesta accidental en niños y adolescentes porque son formulaciones líquidas que se absorben rápidamente y pierden su eficacia. 13 No existe un antídoto específico. Debe recordarse que se excreta por la leche materna, por lo cual se recomienda su uso con precaución.…”

A Case of Naphazoline Intoxication after the Ingestion of a Topical Antiseptic Solution

“…Some reports of naphazoline intoxication pointed out that the manufacturer did not indicate systemic side effects of naphazoline. 1 Naphazoline has a narrow therapeuticto-toxic window. 6 In our case, the patient ingested only 15 ml of solution, producing a dose of 0.24 mg/kg of naphazoline.…”

“…Inappropriate use or unintentional ingestion of naphazoline can quickly cause severe CNS depression and cardiovascular adverse effects. 1 Systemic vasoconstriction through peripheral α-adrenoceptors leads to arterial hypertension with reflex bradycardia and possible ischaemia of vital organs. Stimulation of central alpha-adrenoceptors leads to CNS depression, ranging from drowsiness to coma, persisting cardiovascular hypotension, reduced respiratory rate leading to Cheyne-Stokes breathing and possibly pulmonary oedema.…”

Comprehensive review of cardiovascular toxicity of drugs and related agents

“…Similarly, local application of these drugs in order to stop bleeding can provoke hypertension with reflex bradycardia and severe rebound hypotension . Bradycardia and mild hypotension were also observed after oral ingestion of a relatively large amount (0.1 g in a 5‐year old boy) of naphazoline …”

“…448 Bradycardia and mild hypotension were also observed after oral ingestion of a relatively large amount (0.1 g in a 5-year old boy) of naphazoline. 449 p-Synephrine, an isomer of phenylephrine, was considered to be an alternative for ephedra products after their ban. It is a natural compound found in Citrus aurantium subsp.…”