The nurse is caring for an older adult who is receiving diphenoxylate with atropine to treat severe diarrhea. The nurse will monitor this patient closely for which effect?

A. As requested by the patient.

Administering the drug only when requested by the patient may not provide adequate prophylaxis against chemotherapy-induced nausea and vomiting. These medications are often prescribed on a schedule to prevent symptoms rather than treating them reactively.

B. 1 hour after chemotherapy administration.

Waiting until 1 hour after chemotherapy administration may not cover the full period during which nausea and vomiting are likely to occur. The administration schedule for antiemetics is often more extended to provide better coverage.

C. The night before the treatment, the day of the treatment, and for 24 hours after the treatment.

This is the correct choice. Administering phenothiazine antiemetics according to this schedule helps ensure continuous coverage during the critical period when chemotherapy-induced nausea and vomiting are most likely to occur.

D. The day of treatment.

Administering the drug only on the day of treatment may not provide sufficient coverage for the entire duration when chemotherapy-induced nausea and vomiting can occur. Again, the schedule mentioned in option C is more comprehensive for prevention.

A. "Continue taking OCPS because phenytoin is not safe during pregnancy."

This statement is not accurate. While it's essential to address pregnancy risk, phenytoin can reduce the effectiveness of oral contraceptives. Women on phenytoin are often advised to use additional contraceptive measures.

B. "You should use a backup method of contraception along with OCPs."

This is the correct response. Phenytoin can accelerate the metabolism of oral contraceptives, potentially reducing their effectiveness. Using a backup method, such as condoms, is recommended to ensure adequate contraception.

C. "You should stop taking OCPs because of drug-drug interactions with phenytoin."

This advice is generally not recommended without consulting the healthcare provider. Abruptly stopping OCPs without an alternative form of contraception can increase the risk of unintended pregnancy.

D. "You should take low-dose aspirin while taking these medications to reduce your risk of stroke."

This statement is not relevant to the situation described. Low-dose aspirin is not typically recommended for contraception, and its use in this context does not address the potential interaction between phenytoin and oral contraceptives.