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 Biaxin Xl. If you are concerned about side effects, discuss the risks and benefits of Biaxin Xl with your doctor.

The following side effects have been reported by at least 1% of people taking Biaxin Xl. 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.

• abdominal pain
• change in sense of taste
• confusion
• Diarrhea (mild)
• disorientation
• dizziness
• gas
• headache
• hearing trouble
• heartburn
• nausea
• ringing in the ears
• vomiting

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:

• severe abdominal or stomach cramps and pain
• skin rash
• symptoms of liver problems (e.g., abdominal tenderness, yellow eyes or skin, skin rash, itching, dark urine)
• symptoms of Myasthenia Gravis (e.g., muscle weakness, drooping eyelid, vision changes, difficulty chewing and swallowing, trouble breathing)
• watery and severe diarrhea, which may also be bloody

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

• abnormal or irregular heartbeat
• symptoms of a Anaphylaxis (severe allergic reaction) (e.g., Hives; difficulty breathing; sore throat; or swelling of the face, mouth, throat, or tongue)
• symptoms of a severe skin reaction (e.g., peeling or blistering skin)

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 Biaxin Xl.

Each oval, yellow, film-coated, extended-release tablet debossed with the Abbott logo and "LC" on one side, contains 500 mg of clarithromycin. Nonmedicinal ingredients: cellulosic polymers, lactose monohydrate, magnesium stearate, propylene glycol, Quinoline Yellow Lake E104, sorbitan monooleate, talc, titanium dioxide, and vanillin. Biaxin Xl does not contain tartrazine.

Do not take clarithromycin if you:

• are allergic to clarithromycin or any ingredients of Biaxin Xl
• are allergic to other macrolide antibiotics, such as erythromycin or azithromycin
• have had jaundice (yellowing of the skin or eyes) or liver problems associated with taking clarithromycin
• have severe liver failure in addition to decreased kidney function
• have or have had QT prolongation (an abnormal electrical activity of the heart) or an abnormal heart rhythm
• have untreated hypokalemia (low potassium levels in the blood)
• are taking any of the following medications:
• astemizole
• cisapride
• Colchicine
• Domperidone
• ergot alkaloids (e.g., Dihydroergotamine, ergonovine, ergotamine, methylergonovine)
• oral midazolam
• Pimozide
• saquinavir
• "statin" cholesterol lowering medications (e.g., Lovastatin, Simvastatin)
• terfenadine
• Ticagrelor

There may be an interaction between clarithromycin and any of the following:

• Abiraterone acetate
• Aliskiren
• Almotriptan
• alpha-blockers (e.g., Alfuzosin, Doxazosin, Silodosin, Tamsulosin)
• amiodarone
• anti-cancer medications (e.g., Cabazitaxel, Docetaxel, Doxorubicin, Etoposide, Ifosfamide, Irinotecan, Vincristine)
• anti-emetic medications (serotonin antagonists; e.g., Granisetron, Ondansetron)
• antihistamines (e.g., cetirizine, doxylamine, Diphenhydramine, Hydroxyzine, Loratadine)
• antipsychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• Apalutamide
• Apixaban
• Aprepitant
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• bacillus Calmette-Guérin (BCG) vaccine
• benzodiazepines (e.g., Clonazepam, Diazepam, Lorazepam)
• Bicalutamide
• Bosentan
• Brinzolamide
• Bromocriptine
• Buprenorphine
• Buspirone
• Cabergoline
• Calcitriol
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• cannabis
• Carbamazepine
• Carvedilol
• chloroquine
• Cholera vaccine
• Cimetidine
• Cinacalcet
• Clopidogrel
• Cobicistat
• colchicine
• conivaptan
• corticosteroids (e.g., Dexamethasone, Hydrocortisone, Prednisone)
• Cyclosporine
• dabigatran
• Dantrolene
• Darifenacin
• Deferasirox
• Degarelix
• Digoxin
• Disopyramide
• Divalproex
• dofetilide
• domperidone
• Donepezil
• Dronedarone
• Dutasteride
• Edoxaban
• Eletriptan
• Enzalutamide
• Eplerenone
• ergot alkaloids (e.g., dihydroergotamine, ergonovine, ergotamine, methylergonovine)
• estrogens (e.g., conjugated estrogen, Estradiol, ethinyl estradiol, Norethindrone)
• Ethosuximide
• Everolimus
• Fingolimod
• Flecainide
• Fentanyl
• formoterol
• Galantamine
• "gliptin" Diabetes medications (e.g., Linagliptin, Saxagliptin, Sitagliptin)
• grapefruit juice
• Guanfacine
• Hepatitis C antivirals (e.g., asunaprevir, daclatasvir, grazoprevir)
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• Indacaterol
• insulin
• ivermectin
• lidocaine
• lithium
• Lomitapide
• Loperamide
• Macitentan
• other macrolide antibiotics (e.g., azithromycin, erythromycin)
• maraviroc
• medications used to treat diabetes (e.g., Pioglitazone, Rosiglitazone, Repaglinide)
• Mefloquine
• Methadone
• mifepristone
• Mirtazapine
• Modafinil
• Nadolol
• narcotic pain relievers (e.g., Codeine, fentanyl, Morphine, Oxycodone)
• nefazodone
• nitrates (e.g., isosorbide dinitrate, isosorbide mononitrate)
• Oxybutynin
• pentamidine
• Phenobarbital
• Phenytoin
• phosphodiesterase 5 inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
• Prasugrel
• praziquantel
• primidone
• procainamide
• progestins (e.g., Dienogest, Levonorgestrel, medroxyprogesterone, norethindrone)
• Propafenone
• proton pump inhibitors (e.g., Lansoprazole, Omeprazole)
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, Norfloxacin, Ofloxacin)
• Ranitidine
• rifabutin
• rifampin
• rifaximin
• rilpivirine
• Rivaroxaban
• Romidepsin
• salmeterol
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin-norepinephrine reuptake inhibitors (SNRIs; e.g., Duloxetine, Venlafaxine)
• Sirolimus
• sodium picosulfate
• sotalol
• "statin" anti-cholesterol medications (e.g., Atorvastatin, lovastatin, simvastatin)
• St. John's wort
• sulfonylureas (e.g., Glyburide, Tolbutamide)
• Tacrolimus
• Tamoxifen
• theophyllines (e.g., Aminophylline, Oxtriphylline, Theophylline)
• ticagrelor
• Tofacitinib
• Tolterodine
• Tolvaptan
• Tramadol
• Trazodone
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)
• Trimethoprim
• typhoid vaccine
• tyrosine kinase inhibitors (e.g., Dasatinib, imatinib, Nilotinib)
• Ulipristal
• Valproic acid
• vilanterol
• Warfarin
• zidovudine
• 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 the ones listed above may interact with Biaxin Xl. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that 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 Biaxin Xl.

Abnormal heart rhythm: Clarithromycin may cause a heart rhythm problem called QT prolongation. If you have a history of QT prolongation, a medical condition associated with QT prolongation, or are taking certain medications (e.g., Amiodarone, Sotalol), discuss with your doctor how Biaxin Xl may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Biaxin Xl, and whether any special monitoring is needed.

Allergy: If you have had some form of allergy to erythromycin or azithromycin, you may be more likely to have an allergic reaction to Biaxin Xl. If you develop symptoms of an allergic reaction such as a rash, contact your doctor. If you develop hives; difficulty breathing; or swelling of the face, mouth, throat, or tongue, stop taking Biaxin Xl and get immediate medical attention.

Bacterial resistance: Misuse of an antibiotic such as clarithromycin may lead to the growth of resistant bacteria that will not be killed by the antibiotic. If this happens, the antibiotic may not work for you in the future. Although you may begin to feel better when you first start taking clarithromycin, you need to take all of the medication, exactly as prescribed by your doctor, to finish ridding your body of the infection and to prevent resistant bacteria from taking hold. Do not take clarithromycin or other antibiotics to treat a viral infection such as The Common Cold; antibiotics do not kill viruses, and using them to treat viral infections can lead to the growth of resistant bacteria.

Diarrhea: As with other antibiotics, clarithromycin is associated with a serious infection called Clostridium difficile-associated diarrhea, caused by the bacteria C. difficile. This can occur as late as 2 months after your last dose of Biaxin Xl.

If you have loose, watery bowel movements especially if they are green, foul-smelling, or bloody and accompanied by Fever, either during or after taking clarithromycin, get medical attention as soon as possible.

Dizziness, confusion, and disorientation: Biaxin Xl can cause dizziness, confusion, or disorientation. Do not drive or operate machinery until you are certain that Biaxin Xl does not affect your ability to perform these tasks safely.

Kidney function: Kidney Disease or reduced kidney function may cause Biaxin Xl to build up in the body, causing side effects. If you have reduced kidney function, discuss with your doctor how Biaxin Xl may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Biaxin Xl, and whether any special monitoring is needed.

Liver problems: Liver disease or reduced liver function may cause Biaxin Xl to build up in the body, causing side effects. If you have reduced liver function, discuss with your doctor how Biaxin Xl may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Biaxin Xl, and whether any special monitoring is needed. Biaxin Xl should not be used by people with severe liver problems.

If you develop symptoms of liver problems (e.g., loss of appetite, nausea, vomiting, yellowing of the skin or eyes, dark urine, itchy skin, abdominal pain), contact your doctor immediately.

Myasthenia gravis: Biaxin Xl can worsen or cause symptoms of myasthenia gravis. If your symptoms worsen or you develop new symptoms such as double vision, drooping eyelids, muscle weakness, or difficulty chewing or swallowing, contact your doctor.

Pregnancy: Clarithromycin should not be used during pregnancy, especially the first 3 months of pregnancy, unless there is no other appropriate therapy. If you become pregnant while taking Biaxin Xl, contact your doctor.

Breast-feeding: Biaxin Xl passes into breast milk. If you are a breast-feeding mother and are taking clarithromycin, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using clarithromycin oral suspension have not been established for children younger than 6 months old. For pneumonia, the use of clarithromycin oral suspension has not been studied for children younger than 3 years old. The safety and effectiveness of using clarithromycin to prevent MAC infection has not been studied for children younger than 20 months old. The safety and effectiveness of using clarithromycin tablets have not been established for children younger than 12 years old.