What is the best medication for atrial flutter when Cardizem (Diltiazem) 10mg is ineffective?

From the Guidelines

For atrial flutter when Cardizem (diltiazem) 10 mg has been ineffective, amiodarone is the best alternative, as it can be started at 400-600 mg daily for 2-4 weeks, then reduced to 200 mg daily for maintenance, and has been shown to be effective in maintaining sinus rhythm in patients with symptomatic, recurrent atrial flutter, according to the 2015 ACC/AHA/HRS guideline 1. When considering alternative treatments, it's essential to evaluate the patient's underlying heart disease and comorbidities. Amiodarone blocks multiple ion channels, potentially providing better rhythm control compared to diltiazem. However, before starting amiodarone, a cardiologist evaluation is crucial due to its significant side effects and contraindications, such as effects on thyroid function and lungs 2. Some key points to consider when prescribing amiodarone include:

• Starting dose: 400-600 mg daily for 2-4 weeks
• Maintenance dose: 200 mg daily
• Potential side effects: hypotension, bradycardia, QT prolongation, torsade de pointes, GI upset, constipation, phlebitis (IV)
• Contraindications: none specified, but caution is advised in patients with structural heart disease or ischemic heart disease Additionally, anticoagulation therapy is typically needed alongside amiodarone to prevent stroke, and the choice of anticoagulant should be based on the patient's individual risk factors and medical history. It's also important to note that catheter ablation of the CTI is a recommended treatment option for patients with atrial flutter that is either symptomatic or refractory to pharmacological rate control, according to the 2015 ACC/AHA/HRS guideline 1. However, this option should be considered on a case-by-case basis, taking into account the patient's specific condition and medical history.

From the FDA Drug Label

In patients without structural heart disease, propafenone is indicated to prolong the time to recurrence of – paroxysmal atrial fibrillation/flutter (PAF) associated with disabling symptoms. As with other agents, some patients with atrial flutter treated with propafenone have developed 1:1 conduction, producing an increase in ventricular rate. Concomitant treatment with drugs that increase the functional AV refractory period is recommended.

Propafenone may be considered for atrial flutter when cardezam 10 mg didn’t work, as it is indicated for the treatment of paroxysmal atrial fibrillation/flutter (PAF) associated with disabling symptoms 3.

• However, it is crucial to note that propafenone may cause 1:1 conduction in some patients with atrial flutter, leading to an increase in ventricular rate.
• Concomitant treatment with drugs that increase the functional AV refractory period is recommended to mitigate this risk.

From the Research

Alternative Medications for Atrial Flutter

If Cardezam 10 mg did not work, the following medications may be considered as alternatives:

• Ibutilide: likely to result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up, with a moderate certainty of evidence 4
• Propafenone: likely to result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up, with a moderate certainty of evidence 4
• Dofetilide: may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up, with a low certainty of evidence 4
• Sotalol: may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up, with a low certainty of evidence 4
• Procainamide: may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up, with a low certainty of evidence 4
• Flecainide: may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up, with a low certainty of evidence 4, but it can also induce 1:1 atrial flutter, as reported in a case study 5
• Vernakalant: may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up, with a low certainty of evidence 4
• Diltiazem: rapidly effective for slowing the ventricular response in most patients with atrial fibrillation or atrial flutter, with a high response rate of 94% 6
• Metoprolol: can be used in combination with flecainide to reduce atrial fibrillation clinical recurrences and improve tolerability at 1-year follow-up in persistent symptomatic atrial fibrillation 7

Key Considerations

When choosing an alternative medication, it is essential to consider the patient's comorbidity profile, the onset of action and side effect profile of the antiarrhythmic drug, and the need for a physician with experience in sedation or anaesthetics support for electrical cardioversion 4. Additionally, the potential for adverse effects, such as hypotension and bradycardia, should be carefully evaluated 8.