Adrenoceptor agonist poisoning after accidental oral ingestion of brimonidine eye drops.
OBJECTIVE
Brimonidine tartrate is a relatively selective alpha(2) adrenic agonist that lowers elevated intraocular pressure. A 2-yr-old boy presented with severe cardiorespiratory symptoms of systemic alpha(2) adrenergic intoxication after accidentally ingesting 2 mL of brimonidine ophthalmic solution (0.2%) orally. At 20 mins after ingestion, he became acutely pale and lethargic, with shallow infrequent respirations. The symptoms resolved completely within the next 10 hrs.


METHODS
The pharmacokinetics of brimonidine in plasma and urine were analyzed using gas chromatography and mass spectrometry.


RESULTS
Maximum plasma concentrations were 40 ng/mL 5 hrs after ingestion. The plasma elimination half-life value was 2.7 hrs. Elimination via urine was calculated as having a terminal half-life value of 3.2 hrs.


CONCLUSIONS
This case illustrates the ability of brimonidine to gain rapid access to the central nervous system. This first passage is followed by a redistribution phase with rising plasma concentrations. Children who accidentally ingest brimonidine orally should be admitted to a pediatric intensive care unit.
Hoffmann
Ullrich
U
Department of Pharmacology, Ernst-Moritz-Arndt University Greifswald, Friedrich-Loeffler-Str. 23d, D-17487 Greifswald, Germany.
Kuno
Saskia
S
Franke
Gerd
G
Fusch
Christoph
C
Haas
Johannes P
JP
D000284:Administration, Oral; D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000506:poisoning*; D000068438:Brimonidine Tartrate; D002675:Child, Preschool; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D009883:Ophthalmic Solutions; D011810:Quinoxalines / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000506:poisoning*
D000316:Adrenergic alpha-Agonists; D009883:Ophthalmic Solutions; D011810:Quinoxalines; D000068438:Brimonidine Tartrate