Bethanechol has been prescribed for a client with gastroesophageal reflux disease (GERD). The nurse should assess the client for which of the following adverse effects?
Constipation.
Urinary urgency.
Hypertension.
Dry oral mucosa.
The Correct Answer and Explanation is:
Correct Answer: Urinary urgency.
Bethanechol is a cholinergic (parasympathomimetic) agonist, meaning it mimics the effects of the parasympathetic nervous system by stimulating muscarinic receptors. It is commonly prescribed to treat urinary retention by promoting bladder contraction and, in some cases, used off-label to manage symptoms of gastroesophageal reflux disease (GERD) by increasing the tone and motility of the gastrointestinal (GI) tract.
Because bethanechol activates muscarinic receptors, it enhances smooth muscle tone in various organs, including the bladder and gastrointestinal system. In GERD, the medication helps by increasing lower esophageal sphincter (LES) tone and promoting gastric emptying, which reduces the frequency and severity of reflux episodes.
However, this widespread muscarinic activation can also lead to undesirable side effects, especially in tissues with high muscarinic receptor sensitivity. One such adverse effect is urinary urgency or frequency, as the drug increases detrusor muscle tone and promotes bladder contraction—even when the bladder is not full. This can result in the urge to urinate frequently or involuntarily, especially in clients with a sensitive bladder.
Now, let’s review the other options:
- Constipation: This is incorrect because bethanechol increases GI motility. A more likely effect would be diarrhea or abdominal cramping, not constipation.
- Hypertension: This is incorrect because muscarinic receptor stimulation typically leads to vasodilation and a decrease in blood pressure, not an increase.
- Dry oral mucosa: Incorrect. Bethanechol increases exocrine gland secretions, including saliva, which would result in increased salivation, not dryness.
In summary, the nurse should monitor the client for urinary urgency due to bethanechol’s parasympathomimetic action, which stimulates bladder contraction and may lead to frequent or involuntary urination. Recognizing this side effect is critical in ensuring safe and effective medication use.