When monitoring a patient using cascara sagrada, the nurse should watch for which of the following side effects?

Cascara sagrada is a natural laxative derived from the bark of the Rhamnus purshiana tree. Its primary action is to stimulate bowel movements, which can lead to increased elimination of water and electrolytes through the intestines. Due to these properties, monitoring for electrolyte imbalances is essential when a patient is using this medication.

Electrolyte imbalances can occur because the increased bowel activity may lead to significant loss of important electrolytes such as potassium, sodium, and magnesium. This can result in symptoms such as muscle weakness, cramps, or abnormal heart rhythms, which are critical to identify in a clinical setting. By keeping a close watch for these potential imbalances, the nurse can help mitigate risks associated with this treatment and promote patient safety.

The other options, such as weight gain, insomnia, or skin rash, are not typically associated with cascara sagrada. Weight gain is unlikely as the laxative effect would generally lead to the opposite. Insomnia and skin rashes are results of other causes and don’t directly correlate with the mechanism of action of cascara sagrada. Therefore, the focus should remain on monitoring electrolyte levels for patients using this substance.