Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes Multaq (Dronedarone). If you are concerned about side effects, discuss the risks and benefits of Multaq (Dronedarone) with your doctor.

The following side effects have been reported by at least 1% of people taking Multaq (Dronedarone). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• Diarrhea
• heartburn
• nausea
• rash
• skin sensitivity to sunlight
• stomach pains
• taste changes
• tiredness
• vomiting
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• chest pain
• dizziness
• inflammation of the skin
• itchy, red skin
• signs of liver problems (e.g., yellow skin or eyes, abdominal pain, dark urine, clay-coloured stools, loss of appetite, nausea and vomiting, or itching)
• slow heart rate
• shortness of breath when lying down or sleeping
• swelling of the feet or lower legs
• sudden weight gain

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of an allergic reaction (e.g., difficulty breathing, coughing, or wheezing; Hives; itchy skin rash)
• signs of angioedema (e.g., swelling of the face, lips, mouth, tongue or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Multaq (Dronedarone).

Each white film-coated tablet for oral administration, oblong-shaped, engraved with a double wave marking on one side and "4142" code on the other side contains Multaq (Dronedarone) hydrochloride equivalent to Multaq (Dronedarone) 400 mg. Nonmedicinal ingredients: colloidal anhydrous silica, crospovidone, hypromellose, lactose monohydrate, magnesium stearate, maize starch, and poloxamer 407; coating: carnauba wax, hypromellose, macrogol 6000, and titanium dioxide.

Do not take Multaq (Dronedarone) if you:

• are allergic to Multaq (Dronedarone) or any ingredients of the medication
• are pregnant or breast-feeding
• are taking a medication such as ketoconazole, itraconazole, Voriconazole, cyclosporin, telithromycin, clarithromycin,nefazodone, or ritonavir
• are taking a medication that can cause a change in heart rhythm called torsades de pointes (e.g., phenothiazines [promethazine, Chlorpromazine], tricyclic antidepressants [Amitriptyline, Clomipramine, Desipramine], Flecainide, Propafenone, quinidine, Disopyramide, Sotalol, Amiodarone
• have a heart rate less than 50 beats per minute
• have a type of atrial fibrillation called permanent atrial fibrillation (where a decision has been made by the doctor not to try to change the heart rhythm back to normal)
• have an electrocardiogram (ECG) that shows a problem with the electrical activity of the heart called QT prolongation
• have second- or third-degree heart block or sick sinus syndrome (except if treated with a pacemaker)
• have severe Congestive Heart Failure (CHF) or another condition associated with unstable heart function
• have severe left ventricular dysfunction
• have severely reduced liver function
• have liver or lung toxicity related to a prior use of the medication amiodarone

There may be an interaction between Multaq (Dronedarone) and any of the following:

• Alfuzosin
• Aliskiren
• amantadine
• amiodarone
• antihistamines (e.g., cetirizine, doxylamine, Diphenhydramine, Hydroxyzine, Loratadine)
• antipsychotics (e.g., chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• Apixaban
• barbiturates (e.g., butalbital, pentobarbital Phenobarbital)
• benzodiazepines (e.g., Alprazolam, Chlordiazepoxide, Clonazepam, Clorazepate, Diazepam, Flurazepam, midazolam)
• beta-blockers (e.g., Atenolol, Bisoprolol, Metoprolol, Propranolol)
• boceprevir
• Bosentan
• Buspirone
• Bosutinib
• Bromocriptine
• Buprenorphine
• Buserelin
• Calcitriol
• calcium channel blockers (e.g., Verapamil, Diltiazem, Nifedipine)
• cancer medications (e.g., Busulfan, Docetaxel, Etoposide, imatinib, Irinotecan, Vinblastine, Vincristine)
• Captopril
• Carbamazepine
• chloral hydrate
• chloroquine
• Cinacalcet
• Clonidine
• Colchicine
•  inhaled corticosteroids (e.g., budesonide, ciclesonide, fluticasone)
• oral corticosteroids (e.g., Methylprednisolone, Prednisone)
• Crizotinib
• Cyclosporine
• dabigatran
• Darifenacin
• Deferasirox
• Degarelix
• disopyramide
• Digoxin
• Domperidone
• Donepezil
• Doxazosin
• Enzalutamide
• ergot alkaloids (e.g., ergotamine, Dihydroergotamine)
• estrogens (e.g., conjugated estrogen, Estradiol, ethinyl estradiol)
• Famotidine
• Fesoterodine
• Fingolimod
• flecainide
• Galantamine
• grapefruit juice and grapefruit
• Guanfacine
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delaviridine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• imatinib
• Indacaterol
• indapamide
• ledipasvir
• Leuprolide
• lidocaine
• lithium
• Lomitapide
• Loperamide
• macrolide antibiotics (e.g., clarithromycin, erythromycin, telithromycin)
• maraviroc
• Mefloquine
• Methadone
• methamphetamine
• Metoclopramide
• Metronidazole
• mifepristone
• Mirabegron
• Mitotane
• Naloxegol
• narcotic pain relievers (e.g., Codeine, Fentanyl, Morphine, Oxycodone)
• Nateglinide
• nefazodone
• Nilotinib
• nitrates (e.g., isosorbide dintrate)
• Octreotide
• olodaterol
• Pasireotide
• phenobarbital
• Phenytoin
• phosphodiesterase 5 inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
• Pimecrolimus
• Primaquine
• primidone
• procainamide
• propafenone
• Prucalopride
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, Norfloxacin, Ofloxacin)
• Ranitidine
• rifabutin
• rifampin
• Riociguat
• Rivaroxaban
• Rivastigmine
• Romidepsin
• salmeterol
• Saxagliptin
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin antagonists (anti-emetic medications; e.g., Granisetron, Ondansetron)
• Sirolimus
• Sitagliptin
• St. John's wort
• Solifenacin
• sofosbuvir
• "statin" medications (e.g., Atorvastatin, Lovastatin, Simvastatin)
• sulfamethoxazole
• Tacrolimus
• Tamoxifen
• Tamsulosin
• telaprevir
• Theophylline
• Tizanidine
• Tolterodine
• Tolvaptan
• Tramadol
• Trazodone
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, Imipramine, desipramine)
• Trimethoprim
• Ulipristal
• Venlafaxine
• vilanterol
• Warfarin
• Zolpidem
• Zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Multaq (Dronedarone). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Multaq (Dronedarone).

Congestive heart failure: If you have moderate congestive heart failure, discuss with your doctor how Multaq (Dronedarone) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Multaq (Dronedarone), and whether any special monitoring is needed. This medication should not be used for people with severe congestive heart failure. People with severe heart failure who take Multaq (Dronedarone) have an increased chance of dying. If you develop heart failure symptoms or worsening symptoms (e.g., weight gain, increasing shortness of breath, difficulty breathing at night, swelling of the feet or legs) while taking Multaq (Dronedarone), contact your doctor immediately.

Lung problems: Multaq (Dronedarone) can cause lung problems (Pulmonary Fibrosis, inflammation of lung tissue). Tell your doctor immediately if you experience any difficulty breathing, shortness of breath, or Dry Cough while you are taking Multaq (Dronedarone).

Kidney function: The results of a blood test for kidney function, called creatinine, may be increased without a change in your kidney function. Your doctor will use the creatinine level as your new normal. Tell any other doctor you see about the new "normal" value of your blood creatinine.

Liver: There have been reports of liver injury in people who were taking Multaq (Dronedarone). Your doctor may regularly perform tests to monitor your liver function. If you experience symptoms of liver damage (e.g., yellowing of the skin or eyes, fatigue, abdominal pain, nausea, vomiting, dark urine, or itching), contact your doctor immediately.

Low potassium and magnesium levels: Before starting and while taking Multaq (Dronedarone), your doctor may want to check your blood levels of potassium and magnesium, especially if you are taking medications (e.g., Hydrochlorothiazide, Furosemide, Indapamide) that may reduce these levels. If they are low, your doctor may recommend that you take supplements or may make changes to your medications.

QT prolongation: Multaq (Dronedarone) can affect the electrical activity of the heart and cause QT prolongation. You doctor will monitor your heart rhythm regularly while you are taking Multaq (Dronedarone) with a test called an electrocardiogram (ECG). You should not take Multaq (Dronedarone) if your ECG already shows that you have QT prolongation or if you are taking a medication that can cause QT prolongation.

Pregnancy: Multaq (Dronedarone) should not be used during pregnancy. If you become pregnant while taking Multaq (Dronedarone), contact your doctor immediately.

Breast-feeding: It is not known if Multaq (Dronedarone) passes into breast milk. Multaq (Dronedarone) should not be used while breast-feeding.

Children: The safety and effectiveness of using Multaq (Dronedarone) have not been established for children under 18 years of age.