During a routine checkup, a patient states that she is unable to take the prescribed antihistamine because of one of its most common adverse effects. The nurse suspects that which adverse effect has been bothering this patient?

Choice A reason: This is incorrect because withholding all medications may cause hyperglycemia or ketoacidosis in the patient, especially if they are taking insulin or sulfonylureas. The nurse should consult with the prescriber to adjust the dose or timing of the medications according to the patient's blood glucose level and the duration of the procedure.

Choice B reason: This is correct because contacting the prescriber to clarify orders is the best action by the nurse, as the prescriber can provide specific instructions on how to manage the patient's oral antidiabetic drugs before and after the oral endoscopy. The nurse should also monitor the patient's blood glucose level closely and report any abnormal findings to the prescriber.

Choice C reason: This is incorrect because administering half the original dose may not be appropriate for the patient, as it may cause hypoglycemia or hyperglycemia depending on the type and dose of the medication and the patient's blood glucose level. The nurse should not make any changes to the medication regimen without the prescriber's approval.

Choice D reason: This is incorrect because giving the medication with a sip of water may violate the NPO status of the patient, which is necessary to prevent aspiration or interference with the oral endoscopy. The nurse should not administer any oral medications or fluids to the patient unless the prescriber allows it.

Choice A reason: Benzonatate is not the correct answer. Benzonatate is a cough suppressant that works by numbing the throat and lungs. It does not help in the removal of mucus.

Choice B reason: Guaifenesin is the correct answer. Guaifenesin is an expectorant that works by thinning and loosening the mucus in the airways. It helps in the removal of mucus by making it easier to cough up.

Choice C reason: Diphenhydramine is not the correct answer. Diphenhydramine is an antihistamine that works by blocking the effects of histamine, a chemical that causes allergy symptoms. It does not help in the removal of mucus.

Choice D reason: Dextromethorphan is not the correct answer. Dextromethorphan is a cough suppressant that works by affecting the signals in the brain that trigger the cough reflex. It does not help in the removal of mucus.