Does amiodarone (antiarrhythmic medication) affect blood pressure (hypertension/hypotension)?

From the Guidelines

Yes, amiodarone can affect blood pressure, particularly causing hypotension, especially when given intravenously. This antiarrhythmic medication primarily used to treat irregular heart rhythms can cause hypotension (low blood pressure) due to its vasodilatory properties and its negative inotropic effect (reducing heart contractility) 1. The typical oral dose ranges from 100-400 mg daily for maintenance therapy, while IV loading doses are usually 150 mg over 10 minutes followed by infusions.

Key Points to Consider

• Blood pressure effects are more common and pronounced with IV administration, where hypotension occurs in about 10-15% of patients 1.
• Amiodarone also has alpha and beta-adrenergic blocking effects that contribute to its blood pressure-lowering potential 1.
• Patients starting amiodarone should have their blood pressure monitored regularly, especially during initial dosing and dose adjustments.
• Those with pre-existing hypotension or severe heart failure should use amiodarone with caution, and dose adjustments may be necessary if significant blood pressure changes occur.

Monitoring and Precautions

• Baseline assessment should include complete history and physical examination, with special attention to congestive heart failure, arrhythmia symptoms, and concomitant medications 1.
• Close surveillance of heart rate, especially during the first week of treatment, is necessary.
• Regular monitoring of thyroid studies, liver transaminase levels, and digoxin levels (as appropriate) is recommended during outpatient loading and every six months thereafter.

Important Considerations for Intravenous Administration

• Intravenously administered amiodarone causes heart block or bradycardia in 4.9 percent of patients and hypotension in 16 percent 1.
• If these conditions occur, infusion of the drug should be discontinued, or the rate of infusion should be reduced.
• Intravenous amiodarone therapy should not be used in patients with bradycardia or heart block who do not have a pacemaker.

From the FDA Drug Label

WARNINGS Hypotension Hypotension is the most common adverse effect seen with Amiodarone HCl injection. In clinical trials, treatment-emergent, drug-related hypotension was reported as an adverse effect in 288 (16%) of 1836 patients treated with amiodarone HCl injection Clinically significant hypotension during infusions was seen most often in the first several hours of treatment and was not dose-related, but appeared to be related to the rate of infusion.

Amiodarone can affect blood pressure, specifically causing hypotension in some patients. This is a common adverse effect, reported in 16% of patients in clinical trials 2. Hypotension can be clinically significant and may require alterations in amiodarone therapy or additional treatment, including vasopressor drugs, positive inotropic agents, and volume expansion.

• Key points:
  • Hypotension is the most common adverse effect of amiodarone
  • Clinically significant hypotension can occur during infusions, especially in the first several hours of treatment
  • Hypotension may require alterations in amiodarone therapy or additional treatment 2 2

From the Research

Amiodarone's Effect on Blood Pressure

• Amiodarone is a potent coronary and peripheral vasodilator 3, which can affect blood pressure.
• The drug has been shown to have minimal negative inotropic activity and a very low rate of pro-arrhythmia, making it safe for use in patients with coronary artery disease and left ventricular systolic dysfunction 4.
• However, the standard formulation of intravenous amiodarone can cause hypotension due to its solvents 5, 6.
• A newly developed aqueous formulation of intravenous amiodarone (Amio-Aqueous) lacks solvents and does not cause hypotension 5.
• In fact, Amio-Aqueous has been shown to increase mean arterial blood pressure and decrease heart rate in some patients 5.
• On the other hand, the hypotensive effect of intravenous amiodarone can persist throughout the maintenance infusion period 6.
• It is essential to consider the potential effects of amiodarone on blood pressure, particularly in patients with pre-existing hypertension or hypotension, and to monitor their blood pressure closely during treatment 3, 7, 4.