Clarithromycin is used to treat a wide variety of bacterial respiratory tract infections. Clarithromycin is known as a macrolide antibiotic. It works by stopping the growth of bacteria.

This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.

Take this medication by mouth with food as directed by your doctor, usually once daily. Swallow the tablets whole. Do not crush or chew the tablets. Doing so can release all of the drug at once, increasing the risk of side effects.

For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.

The dosage and length of treatment are based on your medical condition and response to treatment.

Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.

Tell your doctor if your condition lasts or gets worse.

Diarrhea, nausea, vomiting, and changes in taste may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

A tablet may rarely appear in your stool. This is more likely to occur if you have certain intestinal conditions (such as ileostomy, colostomy, diarrhea). Contact your doctor or pharmacist for further instructions.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• nausea/vomiting that doesn't stop
• hearing loss
• mental/mood changes
• muscle weakness
• eye problems (such as drooping eyelids, blurred vision)
• trouble speaking
• severe stomach/abdominal pain
• dark urine
• yellowing of eyes or skin

This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop:

• diarrhea that doesn't stop
• abdominal or stomach pain/cramping
• blood/mucus in your stool

If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new yeast infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

Get medical help right away if you have any very serious side effects, including:

• severe dizziness
• fainting
• fast/irregular heartbeat

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• fever that doesn't go away
• new or worsening lymph node swelling
• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking clarithromycin, tell your doctor or pharmacist if you are allergic to it; or to other macrolide antibiotics (such as erythromycin, azithromycin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• liver disease (including liver problems with past clarithromycin use)
• kidney disease
• heart disease (coronary artery disease, heart attack)
• a certain type of muscle disease (myasthenia gravis)

Clarithromycin may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using clarithromycin, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions:

• certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG)
• family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death)

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using clarithromycin safely.

Clarithromycin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using clarithromycin before having any immunizations/vaccinations.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially hearing loss and QT prolongation (see above).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Many drugs besides clarithromycin may affect the heart rhythm (QT prolongation), including amiodarone, disopyramide, dofetilide, pacritinib, pimozide, procainamide, quinidine, sotalol, among others.

Other medications can affect the removal of clarithromycin from your body, which may affect how clarithromycin works. Examples include efavirenz, nevirapine, posaconazole, rifamycins (such as rifabutin), among others.

Clarithromycin can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include colchicine, digoxin, some drugs used to treat erectile dysfunction-ED/pulmonary hypertension (such as sildenafil, tadalafil), ergot alkaloids (such as ergotamine, dihydroergotamine), flibanserin, some statin drugs (such as lovastatin, simvastatin), tamsulosin, tolvaptan, ticagrelor, among others.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor tells you to.

Lab and/or medical tests (such as cultures, liver/kidney function) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of your next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.