Final answer:
In the event of systemic toxicity from pilocarpine hydrochloride (Isopto Carpine), used to treat glaucoma, atropine would be the medication the nurse plans to have available as it acts as a muscarinic antagonist, counteracting the muscarinic agonist effects of pilocarpine.
Step-by-step explanation:
Pilocarpine hydrochloride (Isopto Carpine) is a muscarinic agonist used to treat glaucoma by reducing intraocular pressure, primarily through its action on the smooth muscles of the iris and ciliary muscle, enhancing the drainage of aqueous humor. However, in the event of systemic toxicity from pilocarpine, the nurse would plan to have atropine available as an antidote. Atropine is an anticholinergic that acts as a muscarinic antagonist, which would counteract the effects of excess acetylcholine that can occur during a pilocarpine overdose.
It is key to understand that while pilocarpine treats glaucoma by promoting drainage of intraocular fluid, a systemic overdose stimulates parasympathetic activity excessively, which could be life-threatening. The standard treatment for atropine overdose is, interestingly, pilocarpine, which signifies their opposing pharmacological actions. Therefore, the nurse would use atropine to manage symptoms of pilocarpine toxicity and restore autonomic regulation by blocking the excess muscarinic activity caused by pilocarpine.