Clarithromycin (previously known by its brand name Biaxin) is an antibiotic that's used to treat a variety of bacterial infections in adults and children. It's available as a generic immediate-release tablet and solution taken twice per day and an extended-release tablet taken once per day. Side effects include a metallic or sour taste, nausea, vomiting, and diarrhea.
Clarithromycin is a macrolide antibiotic. It works by stopping bacteria from making certain proteins inside their cells. This causes the bacteria to not be able to grow and survive.
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Contact your healthcare provider immediately if you experience any of the following.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Rare
Fever with or without chills
itching, skin rash
severe stomach cramps and pain
stomach tenderness
unusual bleeding or bruising
vomiting
watery and severe diarrhea, which may also be bloody
yellow eyes or skin
Incidence not known
black, tarry stools
blistering, peeling, or loosening of the skin
blurred vision
chest pain or discomfort
clay-colored stools
confusion about identity, place, and time
cool, pale skin
dark urine
difficulty with swallowing
dizziness
fainting
fast, slow, pounding, or irregular heartbeat or pulse
feeling of unreality
feeling that others are watching you or controlling your behavior
feeling that others can hear your thoughts
feeling, seeing, or hearing things that are not there
increased hunger
joint or muscle pain
light-colored stools
loss of appetite
nightmares
puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
recurrent fainting
red skin lesions, often with a purple center
red, irritated eyes
redness, swelling, or soreness of the tongue
seizures
sense of detachment from self or body
severe mood or mental changes
shakiness
skin eruptions
slurred speech
sores, ulcers, or white spots in the mouth or on the lips
stomach pain
swollen glands
tightness in the chest
unpleasant breath odor
unusual behavior
unusual tiredness or weakness
vomiting of blood
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common
Belching
bloated or full feeling
change in sensation of taste
excess air or gas in the stomach or bowels
headache
indigestion
mild diarrhea
passing gas
Incidence not known
Change in sense of smell
continuing ringing or buzzing or other unexplained noise in the ears
feeling of constant movement of self or surroundings
hearing loss
lightheadedness
loss of taste
mood or mental changes
sensation of spinning
shakiness in the legs, arms, hands, or feet
sore mouth or tongue
swelling or inflammation of the mouth
tongue discoloration
tooth discoloration
trouble sleeping
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More tips for the oral suspension (liquid)
No. Clarithromycin is a macrolide antibiotic. It works differently from penicillin. Both antibiotics are used to treat similar infections, but they're not the same. This means depending on what infection you have, clarithromycin might be a good option if you're allergic to penicillin.
It's best to avoid drinking alcohol while taking antibiotics like clarithromycin. This is because alcohol can make it harder for your body to heal from an illness and can raise your risk of getting another infection.
There are several medications that interact with clarithromycin, so it's important your provider and pharmacist know about all of the medications you're taking. For example, you shouldn't take clarithromycin with lovastatin or simvastatin (Zocor) because doing so raises your risk for severe liver or muscle problems from these medications. And if you're taking other medications, like atorvastatin (Lipitor), digoxin (Lanoxin), and calcium channel blockers, your provider your provider might need to adjust your medication doses and check in with you about side effects regularly throughout treatment. Make sure to tell your provider about all of the medications you're taking before and during treatment with clarithromycin.
Both clarithromycin and azithromycin (Zithromax) are macrolide antibiotics that work well and can treat similar infections. But only clarithromycin can be used for Helicobacter pylori (H. pylori) infection and only azithromycin (Zithromax) can be used to treat certain types of sexually transmitted infections. Additionally, the length of treatment depends on the type of infection, but in general, it's 7 to 14 days with clarithromycin, whereas with azithromycin (Zithromax), it can range from a single dose to up to 5 days.
If you have healthy kidneys, clarithromycin can stay in your body for about 1.5 days after your last dose. But if you have kidney problems, it can take much longer for your body to clear this medication. So if you're having side effects from clarithromycin, it's possible they could potentially last up until the medication has been cleared from your body. Keep in mind that these time frames are estimated based on the half-life of clarithromycin, which can differ slightly from person to person.
Clarithromycin isn't generally recommended in pregnant females due to the potential risk for problems (e.g., heart problems, cleft palate) seen in animal studies. The risk of harm to human babies isn't completely clear. A 2021 human study found that babies born to pregnant females taking clarithromycin weren't harmed. If you're pregnant, your provider might only prescribe clarithromycin for you if there aren't any safer options and if the benefits of taking this medication is greater than its risk of harm. Let your provider know if you're pregnant before taking clarithromycin.
It's generally considered safe to breastfeed while taking clarithromycin because the levels of the medication are low in breastmilk and unlikely to cause side effects to your baby. But to be safe, tell your provider if you're breastfeeding before starting clarithromycin.
Clarithromycin can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Severe allergic reactions to clarithromycin are possible, including life-threatening reactions like facial swelling and anaphylaxis (e.g., closing of the throat). Let your provider know if you have an allergy to antibiotics. If you notice hives, rash, red skin, swelling of the lips or tongue, or difficulty breathing after taking clarithromycin, get medical attention right away.
Additionally, although rare, clarithromycin can cause serious skin reactions, such as Stevens-Johnson syndrome (SJS) and Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). If you notice changes in your skin, such as rash, blisters, skin reddening, or skin peeling, stop using clarithromycin and get medical attention right away.
Though rare, some people who took clarithromycin reported serious liver problems, including liver failure. Get medical attention right away if you notice swelling of your stomach, stomach pain, yellowing of your skin or the whites of your eyes, stool changes (clay-colored stools), nausea, vomiting, confusion, or dark or brown urine. You might need to stop using the medication to prevent further liver damage.
Taking clarithromycin with certain medications can give you serious side effects. Make sure to tell your provider about all of the medications you're taking, especially if you take colchicine (Colcrys, Mitigare), Juxtapid (lomitapide), a statin, certain diabetes medications (e.g., insulin, sulfonylureas, meglitinides), quetiapine (Seroquel), oral blood thinners, or benzodiazepines (e.g., alprazolam (Xanax). Don't start any new medications while taking clarithromycin without asking your provider or pharmacist first to make sure the combination is safe to take.
Clarithromycin can affect your heart rhythm, which can be serious and life-threatening. One example includes lengthening the time period from when the heart pumps and then relaxes. This is known as QT prolongation. Your risk for QT prolongation is higher if you have certain factors, including abnormal electrolyte levels, heart rhythm problems, or are taking other medications that cause heart rhythm problems, such as amiodarone (Pacerone), among others. If you feel your chest pounding, have trouble breathing, have chest pain, or feel faint or lightheaded while taking clarithromycin, call 911 right away.
Though very rare, some studies have reported that people with blood vessel-related heart disease who take clarithromycin are at a higher risk of death from heart problems compared to people who take other antibiotics. While the connection is unclear, your provider will weigh the risks and benefits of this medication for you, especially if you have heart problems. Speak to your provider if you have any concerns.
Although rare, clarithromycin can raise your risk of getting infected with a bacteria called Clostridioides difficile (C. diff), which can cause severe diarrhea. Antibiotics change the amount of normal bacteria in your stomach and intestines. This can cause C. diff to overgrow in your gut and lead to an infection. It's important to recognize the difference between diarrhea as a side effect of clarithromycin and this type of infectious diarrhea. C. diff-related diarrhea can cause rapid heart rate, foul-smelling diarrhea, fever, nausea, frequent bowel movements (even up to 15 times per day) and is an emergency. If you have any of these symptoms, get medical attention right away so you can get tested for C. diff infection and receive treatment.
If you have myasthenia gravis, taking clarithromycin can worsen symptoms like muscle weakness and difficulty breathing. Ask your provider about safer antibiotics if you have myasthenia gravis.
Your provider will prescribe a dose based on the type of infection you have, how severe it is, if you have kidney problems, and if you're taking a medication that interacts with clarithromycin.
Clarithromycin immediate-release tablet and clarithromycin suspension:
Clarithromycin extended-release tablet:
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Clarithromycin will not be safe for you to take.
Adults
Azithromycin (Zithromax) can treat certain types of:
Children
Azithromycin (Zithromax) can treat certain types of: