Atropine ophthalmic effects

Ileus is a potential side-effect of the systemic absorption of ophthalmic atropine in the horse. This may be an idiosyncratic response affecting only a few individual horses but all atropine-treated horses should be monitored for signs of colic. 

If cuff deflation is complicated by sialorrhea anticholinergic medications, such as scopolamine, glycopyrrolate, or amitriptyline may be used. Sublingual, 1% ophthalmic atropine, 1 to 4 drops up to q.i.d. is also effective (65), unless narrow angle closure glaucoma is present. 

Except for a much shorter duration of action, the effects of scopolamine are, for practical ophthalmic purposes, the same as those of atropine. The toxic effects of hyoscine hydrobromide are similar to those of atropine, but with hyoscine bradycardia instead of tachycardia occurs and central stimulation rarely precedes depression. Drowsiness leading to coma is the main central symptom. Idiosyncratic reactions are more l ely to occur with scopolamine than with atropine, and ordinary doses occasionally induce severe reactions. Contact dermatitis of the eyelids is less common with scopolamine than with atropine. 

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