Prolonged cardiovascular effects after unintentional ingestion of tetrahydrozoline

Tetrahydrozoline is an imidazoline derivative with alpha receptor agonist activity widely available in over-the-counter topical ocular and nasal formulations. More than 1,600 cases of oral exposures are reported to United States poison centers annually (1,2). Reports of significant toxicity from tetrahydrozoline ingestion are unusual but have occured primarily in small children after unintentional ingestion (3-6). We report a case of unintentional tetrahydrozoline ingestion with cardiovascular effects persisting for 36 hours.