Symptoms
If applied in excessive quantities to the eye, it may give rise to irritation and stinging.
Post marketing data has shown that excessive systemic exposure, for example due to intentional or accidental overdose of naphazoline (including inadvertent oral ingestion), may lead to severe cardiovascular and/or cerebrovascular adverse reactions.
Excessive or long-term use of this product may result in allergic conjunctivitis, allergic blepharitis or rebound conjunctival hyperaemia. Prolonged use may also lead to epithelial xerosis which can exacerbate symptoms of irritation, pain and dryness experienced in allergic conjunctivitis.
Indiscriminate use of decongestants, such as naphazoline, in an irritated eye can induce papillary dilation and precipitate angle-closure glaucoma in eyes that have narrow anterior chamber angles.
Overdosage by mouth may cause nausea, headache, depression of the central nervous system with marked reduction of body temperature and symptoms of bradycardia, sweating, drowsiness and coma, particularly in children. In addition, may cause hypertension followed by rebound hypotension.
There are no or limited data on overdose of topical hamamelis water, but risks are negligible.
Management
Treatment of adverse effects should be symptomatic and supportive.