Should the beta blocker (metoprolol succinate ER) or losartan (an angiotensin II receptor antagonist) be adjusted in an 83-year-old patient with sick sinus syndrome, paroxysmal atrial fibrillation, and hypertension, currently experiencing orthostatic hypotension?

From the Guidelines

Adjusting the metoprolol succinate ER would be more appropriate than modifying the losartan. Since the patient is currently off losartan with a reasonable blood pressure of 135/78, and previously experienced symptomatic hypotension (BP 107/60 with weakness) when taking losartan 100mg-HCTZ 12.5mg, it would be prudent to maintain the current approach of withholding losartan 1. The metoprolol dose could be reduced from 25mg to 12.5mg daily if the patient continues to experience bradycardia or weakness, especially given the patient's advanced age (83 years) and sick sinus syndrome which predisposes to bradycardia 1. This approach balances the need for rate control for the paroxysmal atrial fibrillation while avoiding excessive bradycardia. The flecainide should be maintained at 100mg daily for rhythm control 1. Blood pressure should be monitored regularly, and if it consistently rises above 140/90, consider reintroducing a lower dose of losartan (25-50mg) without the HCTZ component to minimize hypotensive episodes. This strategy acknowledges the patient's cardiovascular comorbidities while prioritizing symptom management and stroke prevention in this elderly patient with a history of TIA and carotid disease.

Some key points to consider:

• The patient's advanced age and sick sinus syndrome increase the risk of bradycardia, making it essential to balance rate control with the risk of excessive bradycardia 1.
• The use of metoprolol succinate ER is preferred for rate control in patients with paroxysmal atrial fibrillation, especially in those with a history of cardiovascular disease 1.
• Losartan can be reintroduced at a lower dose if blood pressure consistently rises above 140/90, but it is crucial to monitor for signs of hypotension and adjust the dose accordingly 1.
• Flecainide is an effective medication for rhythm control in patients with paroxysmal atrial fibrillation, but its use should be carefully monitored due to the risk of proarrhythmic effects 1.

From the FDA Drug Label

WARNINGS Heart Failure Beta-blockers, like metoprolol, can cause depression of myocardial contractility and may precipitate heart failure and cardiogenic shock. If signs or symptoms of heart failure develop, treat the patient according to recommended guidelines. It may be necessary to lower the dose of metoprolol or to discontinue it Bradycardia Bradycardia, including sinus pause, heart block, and cardiac arrest have occurred with the use of metoprolol. Patients with first-degree atrioventricular block, sinus node dysfunction, or conduction disorders may be at increased risk. Monitor heart rate and rhythm in patients receiving metoprolol. If severe bradycardia develops, reduce or stop metoprolol

The patient has sick sinus syndrome and is experiencing bradycardia (HR 60) and hypotension (107/60). Given this information, it may be necessary to adjust the beta blocker (metoprolol) to avoid exacerbating these conditions. The losartan can be adjusted as needed to control blood pressure, but caution should be exercised to avoid hypotension. 2

From the Research

Patient's Condition

The patient is an 83-year-old with sick sinus syndrome, paroxysmal atrial fibrillation, and a history of TIA and left carotid endarterectomy. The patient is currently taking metoprolol succinate ER 25mg and Flecainide 100mg daily.

Blood Pressure Management

The patient's blood pressure has been fluctuating, with readings as high as 164/80 and as low as 107/60, with a heart rate of 60. The patient has been taking losartan 100mg - HCTZ 12.5mg, which has been adjusted at times, and the beta blocker has also been adjusted.

Treatment Options

• The patient is currently off losartan, with a blood pressure of 135/78.
• Studies have shown that calcium channel blockers can be effective in lowering blood pressure, especially in combination with other drugs 3.
• Combination therapy with thiazide diuretics, calcium channel blockers, angiotensin-converting enzyme inhibitors (ACEIs), and angiotensin receptor blockers (ARBs) can be effective in treating hypertension 4.
• A fixed-dose combination of metoprolol extended release/amlodipine has been shown to be as effective and well-tolerated as losartan plus amlodipine in treating essential hypertension 5.
• Losartan + HCTZ has been shown to be as effective as bisoprolol + HCTZ in reducing blood pressure, with a more positive influence on pulse wave velocity and central systolic blood pressure 6.

Considerations for Adjustment

• The patient's blood pressure variability may be a concern, as studies have shown that pronounced blood pressure changes can introduce errors in diagnosis and treatment of hypertension 7.
• The patient's heart rate and blood pressure should be closely monitored when adjusting medications.
• The choice of medication and dosage should be based on the patient's individual needs and response to treatment.

Potential Adjustments

• The beta blocker or losartan may need to be adjusted to achieve optimal blood pressure control.
• The patient's response to treatment should be closely monitored, and adjustments made as needed to minimize the risk of adverse effects.
• Consideration should be given to the use of combination therapy to achieve optimal blood pressure control, as supported by studies 4, 5, 6.