What is an equivalent oral and rectal metoprolol (Lopressor) order for a patient with advanced dementia refusing oral intake, who is in atrial fibrillation (AFib), instead of 2.5 milligrams of metoprolol administered intravenously (IV) every 6 hours (q6h)?

From the Guidelines

For a patient with advanced dementia in atrial fibrillation who is refusing oral intake and currently receiving metoprolol 2.5 mg IV q6h, an equivalent oral dose would be metoprolol 25 mg q6h, while an equivalent rectal dose would be metoprolol 25 mg q6h as well. The rectal route is likely the better option given the patient's refusal of oral intake. According to the most recent guidelines 1, metoprolol tartrate can be administered orally at a dose of 25–200 mg, twice daily, for rate control in patients with atrial fibrillation. When converting from IV to oral or rectal, it's essential to consider the bioavailability of metoprolol, which is approximately 50% when given orally compared to IV administration, as noted in previous studies 2. This is why the oral/rectal dose needs to be about 10 times higher than the IV dose. When administering metoprolol rectally, use the immediate-release tablet form, crushed and mixed with a small amount of water-soluble lubricant. Some key points to consider when choosing the route of administration include:

• The patient's ability to tolerate oral intake
• The availability of rectal administration protocols for metoprolol
• The potential need for alternative beta-blockers or different medication classes for rate control Monitor the patient's heart rate and blood pressure closely after switching routes to ensure adequate rate control is maintained. If the rectal route proves difficult or ineffective, alternative beta-blockers with established rectal administration protocols or different medication classes for rate control might need to be considered, as outlined in the guidelines 1. The goal remains to maintain adequate rate control for the atrial fibrillation while respecting the patient's advanced dementia status. Key considerations for rate control in atrial fibrillation include:
• Reducing symptoms
• Improving heart function
• Reducing the risk of recurrent cardiomyopathy
• Reducing the risk of inappropriate shock
• Enhancing biventricular pacing, likelihood of myocardial recovery, and/or preservation of function
• Reducing the risk of hospitalization, as noted in the guidelines 1.

From the FDA Drug Label

In patients who tolerate the full intravenous dose (15 mg), metoprolol tartrate tablets, 50 mg every 6 hours, should be initiated 15 minutes after the last intravenous dose and continued for 48 hours Patients who appear not to tolerate the full intravenous dose should be started on metoprolol tartrate tablets either 25 mg or 50 mg every 6 hours (depending on the degree of intolerance)

The equivalent oral order for 2.5 mg IV q6h of metoprolol is not directly stated in the label. However, considering the information provided for patients who do not tolerate the full intravenous dose, a possible oral alternative could be 25 mg every 6 hours. For rectal administration, there is no information provided in the label. Given the context of an advanced dementia patient refusing oral intake, caution should be exercised, and 25 mg every 6 hours orally or through an alternative route (if available) may be considered, but this is not explicitly stated in the label 3.

From the Research

Equivalent Oral and Rectal Metoprolol Order

To determine an equivalent oral and rectal metoprolol order instead of 2.5 mg IV q6h for an advanced dementia patient refusing oral intake who is in atrial fibrillation, we must consider the patient's specific condition and the available evidence.

• The patient's advanced dementia and atrial fibrillation require careful management, as evidenced by studies such as 4 and 5, which highlight the complex relationship between these two conditions.
• However, the provided studies do not directly address the conversion of IV metoprolol to oral or rectal administration in this specific patient population.
• Study 6 discusses the management of swallowing difficulties in people with advanced dementia, which may be relevant to the patient's refusal of oral intake.
• Unfortunately, there is no direct evidence in the provided studies to support a specific equivalent oral and rectal metoprolol order for this patient.

Considerations for Medication Administration

• When considering alternative routes of administration, such as rectal, it is essential to consult relevant clinical guidelines and pharmacological resources, as the provided studies do not offer specific guidance on this topic.
• The patient's individual needs, medical history, and current condition should be taken into account when determining the most appropriate medication administration route.
• Studies such as 7 and 8 focus on the management of atrial fibrillation in patients with advanced dementia, but do not provide information on metoprolol administration routes.