The answer is C: Epinephrine.
Explanation for each option:
A. Spironolactone - This is a potassium-sparing diuretic often used to treat hypertension. It is generally safe for hypertensive patients unless there are specific contraindications like hyperkalemia.
B. Isosorbide dinitrate - This medication is used to prevent angina (chest pain) and can be used in patients with hypertension, especially if they have concurrent heart conditions. It is not typically withheld for hypertensive patients.
C. Epinephrine - This medication is a vasoconstrictor and can increase blood pressure. It is generally not used in hypertensive patients unless in specific emergency situations like anaphylaxis. Therefore, it should be withheld and verified for a hypertensive client.
D. Captopril - This is an ACE inhibitor used to treat hypertension. It is appropriate for hypertensive patients and should not be withheld unless there are specific contraindications.
E. Diphenhydramine - This is an antihistamine used for allergies. While it can cause some increase in blood pressure, it is not typically withheld for hypertensive patients unless there are specific concerns.
In summary, Epinephrine should be withheld and verified for a hypertensive client due to its potential to increase blood pressure.