A patient who has Parkinson disease is being treated with the anticholinergic medication benztropine (Cogentin). The nurse will tell the patient that this drug will have which effect?

A) Pupil constriction: Pupil constriction (miosis) is primarily mediated by the parasympathetic nervous system through muscarinic receptors, not nicotinic receptors. Nicotinic receptors, when stimulated, affect skeletal muscle contraction, not the size of the pupils.

B) Muscle contraction: Nicotinic receptors are located on skeletal muscle cells and are responsible for mediating muscle contraction when activated. When a drug stimulates nicotinic receptors, the expected outcome is muscle contraction, as these receptors play a critical role in neuromuscular transmission.

C) Increase GI motility: While nicotinic receptors are involved in muscle contraction, they are not the primary mediators of gastrointestinal motility. Muscarinic receptors, which are part of the parasympathetic nervous system, primarily control GI motility. Stimulating muscarinic receptors would lead to increased motility, but not nicotinic receptors.

D) Decrease in heart rate: A decrease in heart rate is typically associated with the stimulation of muscarinic receptors, particularly those that influence the parasympathetic nervous system (vagal tone). Nicotinic receptor activation does not directly influence heart rate; in fact, their stimulation is more related to skeletal muscle contraction.

A) Suspect worsening of the anxiety disorder:
While it is possible that the patient's anxiety disorder is worsening, the more likely explanation for the reduced effectiveness of lorazepam is the development of drug tolerance. Over time, patients may require higher doses of a medication to achieve the same therapeutic effect, especially with medications like lorazepam that are used chronically.

B) Contact the provider to discuss changing to another benzodiazepine:
Changing to another benzodiazepine might be an option, but it is more likely that tolerance to lorazepam is the cause of the reduced effect, not an issue with the specific drug. Tolerance is common with long-term use of benzodiazepines, and switching drugs may not address the underlying issue. The first step would be to assess the current medication regimen and discuss possible adjustments with the provider.

C) Understand that the patient has developed tolerance to this drug:
Tolerance occurs when the body becomes accustomed to the effects of a medication over time, requiring higher doses to achieve the same therapeutic effect. This is a common phenomenon with benzodiazepines like lorazepam, which are often used for long periods to manage anxiety. As the patient has been taking lorazepam for six months, this reduced effectiveness is likely due to the development of tolerance, rather than a worsening of the anxiety disorder.

D) Notify the provider and discuss increasing the dose of lorazepam:
While increasing the dose of lorazepam could temporarily relieve symptoms, it is not the most appropriate first step. The nurse should first consider the possibility of tolerance and discuss this with the provider before increasing the dose. Long-term increases in benzodiazepine dosages can increase the risk of side effects, dependency, and withdrawal symptoms.