Multaq (dronedarone) is a prescription medication used to reduce the risk of hospitalization in people with atrial fibrillation. Specifically, it’s approved for adults who are currently in normal heart rhythm but have a history of episodes where their heart rhythm became irregular, a pattern known as paroxysmal or persistent atrial fibrillation. The goal isn’t to treat an active episode of irregular rhythm but to help keep the heart beating normally and prevent the complications that lead to hospital stays.
How Multaq Works in the Heart
Your heart’s rhythm depends on electrical signals that flow through cardiac muscle in a precise sequence. These signals are controlled by tiny channels in heart cells that let charged particles (sodium, potassium, and calcium) move in and out. In atrial fibrillation, the upper chambers of the heart fire chaotic electrical signals instead of steady ones, causing an irregular and often rapid heartbeat.
Multaq works by affecting multiple types of these ion channels at once. It slows the flow of potassium out of heart cells, which extends the time each cell needs before it can fire again. This makes it harder for rogue electrical signals to take hold. It also partially blocks sodium and calcium channels, further stabilizing the heart’s electrical activity. On top of that, Multaq slows the heart rate and reduces how quickly electrical impulses travel through cardiac tissue. This combination of effects across several pathways is what makes it a broad-acting rhythm control medication.
Who It’s Meant For
Multaq is specifically indicated for people whose hearts are currently in normal sinus rhythm but who have had past episodes of atrial fibrillation or atrial flutter. It’s a maintenance medication, meaning you take it to prevent future episodes rather than to stop one that’s already happening.
This distinction matters because Multaq is not appropriate for everyone with atrial fibrillation. It is not used in people with permanent atrial fibrillation, where the irregular rhythm is constant and the goal of returning to normal rhythm has been abandoned. In clinical trials, patients with permanent atrial fibrillation and certain types of heart failure who took dronedarone had worse outcomes, including increased risk of death. Your doctor will confirm your heart rhythm status before prescribing it.
Evidence for Reducing Hospitalizations
The landmark clinical trial supporting Multaq’s approval, known as ATHENA, enrolled high-risk patients with atrial fibrillation or atrial flutter. Compared to a placebo, patients taking Multaq had a 24% reduction in cardiovascular hospitalizations or death over the study period. In concrete terms, 31.9% of patients on Multaq experienced a cardiovascular hospitalization or death, compared to 39.4% in the placebo group. This trial is the primary reason the drug is approved specifically to reduce hospitalizations rather than simply to control heart rhythm.
How to Take It
The standard dose is 400 mg twice daily, taken as one tablet with your morning meal and one tablet with your evening meal. Taking it with food is essential, not optional. Without food, your body absorbs only about 4% of the drug. With a meal, absorption jumps to roughly 15%. That difference can determine whether the medication actually reaches effective levels in your system, so skipping meals while on Multaq undermines its purpose.
Common Side Effects
The most frequently reported side effects are digestive. In clinical trials involving over 3,200 patients taking the standard dose, diarrhea was the most common complaint, affecting about 9% of patients compared to 6% on placebo. Nausea occurred in about 5% (versus 3% on placebo), and abdominal pain in about 4% (versus 3%). Vomiting and general weakness were also reported more often than in the placebo group. These side effects are typically mild to moderate, but if persistent diarrhea or stomach discomfort becomes disruptive, it’s worth discussing with your prescriber.
Important Safety Concerns
Multaq carries serious safety warnings for specific patient populations. It should not be used in people with severe heart failure, as studies showed increased mortality in this group. It is also contraindicated in permanent atrial fibrillation. Before starting treatment, your doctor will likely check your heart rhythm with an ECG and may order blood tests to assess liver function, since rare cases of liver injury have been reported with this medication.
Multaq interacts with a number of other medications. It affects certain liver enzymes involved in drug metabolism, which means it can raise or lower the blood levels of other drugs you’re taking. Other heart rhythm medications, certain antibiotics, antifungals, and some common prescriptions can interact with it significantly. Your doctor and pharmacist will review your full medication list before you start.
Because Multaq can slow heart rate and affect electrical conduction, periodic monitoring with ECGs is typical, especially early in treatment. If your atrial fibrillation becomes permanent while you’re on Multaq, the medication should be stopped.