A 70-year-old client comes to the hospital for after suffering a syncopal episode. Patient states that she felt dizzy when she stood up, then passed out. The client's blood pressure on admission is 88/48 mmHg. A list of medications is obtained as part of the medication reconciliation process. Which three medications are most likely to have contributed to this client's signs and symptoms? (Select all that apply.)

A. Diltiazem: This calcium channel blocker reduces blood pressure and slows the heart rate, both of which can contribute to orthostatic hypotension. In a 70-year-old patient, the baroreceptor reflex is less efficient, making them more susceptible to syncopal episodes during position changes. Lowering systemic vascular resistance too much can result in an acute drop in cerebral perfusion. B. Carbidopa/levodopa: This medication is primarily used to treat Parkinson's disease and, while it can cause some hypotension, it is not a primary cardiovascular agent. Its impact on blood pressure is generally less profound than that of diuretics or dedicated antihypertensives. It is less likely than the other choices to be the primary driver of a blood pressure of 88/48. C. Hydrochlorothiazide: Diuretics reduce the total intravascular volume by promoting the excretion of sodium and water. A decrease in blood volume directly lowers the blood pressure and can lead to dehydration-related syncope. This medication is a very common cause of orthostatic dizziness and falls in the geriatric population. D. Metoprolol: As a beta-blocker, metoprolol reduces cardiac output and inhibits the compensatory tachycardia usually seen when standing. This prevents the body from quickly adjusting the blood pressure during postural changes, leading to the reported dizziness. The combination of reduced heart rate and reduced force of contraction contributes to the hypotensive state. E. aspirin: Aspirin is an antiplatelet agent used for the prevention of cardiovascular events and does not have a direct effect on blood pressure. It does not cause vasodilation, volume depletion, or changes in heart rate that would lead to syncope. Its primary side effects are related to gastrointestinal irritation and bleeding risks rather than hemodynamics.