Imidazoline intoxication in children

Abstract

A 15-month-old girl with rhinopharyngitis was treated with a nasal solution containing the imidazoline derivative naphazoline. She rapidly developed profound CNS depression with stupor, hypothermia, hypoventilation and bradycardia. All symptoms disappeared within 24 h. The symptomatology of 18 other paediatric cases of naphthylimidazoline exposure reported to the Belgian National Poison Centre, is also discussed. Imidazoline intoxication due to overdose or accidental ingestion but also after normal therapeutic usage is frequent in children. It can cause severe CNS depression, especially in very young children. For these reasons vasoconstrictor imidazoline containing solutions should be prescribed with caution and kept out of reach of children.

CHAMACON: exposiciones potencialmente letales en pediatría

“…En algunos casos el cuadro va precedido de un breve periodo de hipertensión arterial por estímulo α 1 . 43 Debido a que no existen pruebas específicas el diagnóstico se basa en la presentación clínica. En este caso la descontaminación gástrica posee un papel muy limitado debido a la rápida absorción de estos compuestos, por lo que el tratamiento se basa en la terapia de sostén, la cual consiste en administración de cristaloides como primera medida para corregir los estados hipotensivos, seguida del apoyo con aminas en caso de requerirse.…”

Unintentional Pediatric Ophthalmic Tetrahydrozoline Ingestion: Case Files of the Medical Toxicology Fellowship at the University of California, San Francisco

“…Other topical imidazolines such as naphazoline and xylometazoline (0.1 % or more) have also been reported to cause toxicity in children [16][17][18]. Some cases involved adulteration of drinks with THZ as a prank, believing it would cause diarrhea [19].…”

“…Close observation of neurological and hemodynamic status of the patients for at least 24 h and supporting their hemodynamics are done if needed with intravascular fluid in cases of hypotension and atropine if significant bradycardia and hypotension occur [16]. If the initial transient hypertension is severe, it should be treated with a short-acting vasodilator like nitroprusside or phentolamine [32,48].…”

“…The purported mechanism of naloxone effect was reversal of clonidine-enhanced endogenous opiate release, but animal studies have not confirmed this [52,53]. There are several reports of failure of naloxone to reverse clonidine [54,55] and toxicity from THZ and other imidazoline derivatives [12,16,44]. Of course, it is reasonable to try naloxone in a patient presenting with neurological and respiratory depression and miotic pupils, because of the possibility of unrecognized opioid toxicity [56].…”

Prolonged cardiovascular effects after unintentional ingestion of tetrahydrozoline

“…Absorption of tetrahydrozoline, with systemic adverse effects, can occur from both the nasal mucosa and gastrointestinal tract after intranasal administration (7,8). Clinical reports suggest that tetrahydrozoline shares pre-synaptic alpha 2 -receptor agonist effects of the other imidazolines (3)(4)(5)(6).…”