Azithromycin

Azithromycin (Zithromax) is a macrolide antibiotic. It's used to treat many types of infections in children and adults, including strep throat, sinus infection, and pneumonia. Azithromycin (Zithromax) is taken by mouth once daily. Typically, the length of treatment ranges from 3 to 5 days, depending on the type of infection you have. For convenience, azithromycin (Zithromax) also comes pre-packaged as Z-Pak. Some of the more common side effects of azithromycin (Zithromax) include diarrhea, stomach pain, and nausea.

What is Azithromycin (Zithromax) used for?

Adults

Azithromycin (Zithromax) can treat certain types of:

• Sudden worsening of chronic obstructive pulmonary disease (COPD) from a bacterial infection
• Bronchitis
• Sinus infections
• Pneumonia
• Strep throat
• Tonsil infections
• Skin infections (e.g., cellulitis)
• Urethra or cervix infections
• Genital ulcer disease (chancroid)

Children

Azithromycin (Zithromax) can treat certain types of:

• Ear infections (ages 6 months and older)
• Pneumonia (ages 6 months and older)
• Strep throat (ages 2 years and older)
• Tonsil infections (ages 2 years and older)

How Azithromycin (Zithromax) works

Azithromycin (Zithromax) is a macrolide antibiotic. It works by stopping bacteria from making certain proteins inside their cells. As a result, the bacteria aren't able to grow and spread. And sometimes, the bacteria also aren't able to survive.

When does Azithromycin (Zithromax) start working?

Time passed since treatment started:

• You can take azithromycin (Zithromax) with or without food. If it's upsetting your stomach, try taking it with food to help.
• Take azithromycin (Zithromax) exactly as prescribed. Make sure to finish your treatment course, even if you're feeling better. Stopping the medication earlier than prescribed can make your infection come back and become harder to treat.
• If you start to have fever and watery or bloody diarrhea anytime during treatment or after stopping azithromycin (Zithromax), get medical help right away. These might be signs of C. difficile-related diarrhea, which needs medical attention right away.
• If you experience diarrhea from taking azithromycin (Zithromax), let your HCP know. If they think the diarrhea isn't too serious, they might recommend that you take a probiotic to help lessen this side effect.
• If your HCP recommends a probiotic with azithromycin (Zithromax), make sure to separate the two medications by at least 2 hours to prevent azithromycin (Zithromax) from killing the "good" bacteria in the probiotic.
• Though rare, azithromycin (Zithromax) might cause ringing in the ears or hearing loss. Let your HCP know right away if you experience this side effect. They can let you know if you should continue azithromycin (Zithromax) treatment or whether you need more medical attention.
• If you're prescribed azithromycin (Zithromax) for a sexually transmitted infection, make sure your sexual partner(s) also get treated. If they don't, they could reinfect you or others. Most states allow you to ask your healthcare professional for a prescription for your partner(s) without them present. This is called expedited partner therapy. Ask your prescriber if this is an option where you live.

More tips for the oral suspension (liquid)

• The azithromycin (Zithromax) suspension is available as 100 mg/5 mL and 200 mg/5 mL strengths. Make sure you know which strength of the suspension you have to ensure you're taking the correct dose.
• Shake the bottle well before measuring out the azithromycin (Zithromax) suspension. Make sure to only use a medication dose cup or syringe from the pharmacy to measure out your dose. Don't use household spoons because they aren't accurate and might cause you to take the wrong dose.
• You can store azithromycin (Zithromax) suspension at room temperature or in the fridge (but not below 41 degrees F). Storing it in the fridge might help make it taste better.
• The azithromycin (Zithromax) suspension can be stored for up to 10 days after you receive it from the pharmacy. After 10 days, throw away the bottle, even if it still has medication in it.

What are the risks and warnings for Azithromycin (Zithromax)?

Azithromycin (Zithromax) 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 and skin reactions

Severe allergic reactions to azithromycin (Zithromax) are possible, including life-threatening reactions like facial swelling and anaphylaxis (e.g., closing of the throat). Let your HCP 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 azithromycin (Zithromax), get medical attention right away. Additionally, although rare, azithromycin (Zithromax) 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 azithromycin (Zithromax) and get medical attention right away.

Liver damage

• Risk factors: History of liver problems

Azithromycin (Zithromax) can cause serious liver problems that can lead to 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.

Heart rhythm problems (QT prolongation)

• Risk factors: Older adults | Low blood potassium or magnesium levels | Kidney problems | Heart rate or heart rhythms problems | Taking other medications that can cause QT prolongation

Azithromycin (Zithromax) 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 shortness of breath, have chest pain, or feel faint or lightheaded while taking azithromycin (Zithromax), call 911 right away.

Possible higher risk of death from heart problems

Though very rare, some studies have reported that people who take azithromycin (Zithromax) are at a higher risk of death from heart problems compared to people who take other antibiotics. This risk appears to be short term, and is highest during the first five days of taking azithromycin (Zithromax). While the connection is unclear, your prescriber will weigh the risks and benefits of this medication for you. Speak to your HCP if you have any concerns.

Diarrhea from Clostridioides difficile infection

Although rare, azithromycin (Zithromax) 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 azithromycin (Zithromax) 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.

Worsening of certain muscle problems (myasthenia gravis)

If you have myasthenia gravis, taking azithromycin (Zithromax) can worsen symptoms like muscle weakness and difficulty breathing. Ask your HCP about safer antibiotics if you have myasthenia gravis.

Doesn't treat syphilis

Infections of the urethra and cervix that aren't caused by gonorrhea can sometimes be caused by syphilis in its early stages. Azithromycin (Zithromax) doesn't treat syphilis, and taking it can make it harder to tell if you have a current syphilis infection. If you're taking azithromycin (Zithromax) for a sexually transmitted infection (STI) and your symptoms don't improve, contact your HCP because you might need to be tested for syphilis too.

Bottle of oral suspension

• 15ml of 100mg/5ml
• 15ml of 200mg/5ml
• 22.5ml of 200mg/5ml
• 30ml of 200mg/5ml

Packet

• 1g | 1 packet

Tablet

• 250mg 
• 500mg
• 600mg

Tri-pak

• 3 tablets of 500mg | 1 tri-pak

Z-pak

• 6 tablets of 250mg

The dosing is the same for the tablets and suspension.

Adults

• Pneumonia, COPD, strep throat, tonsil infections, and skin infections: The typical dose is 500 mg by mouth on Day 1, then 250 mg daily on Days 2 through 5.
• Sinus infections and COPD: The typical dose is 500 mg by mouth once daily for 3 days
• Chancroid, and infections of the urethra and cervix: The typical dose is 1 gram to 2 grams (depending on the infection) by mouth as a single dose.

Children

Your child's pediatrician will calculate their dose based on their body weight.

• Ear infection: The typical dose can range from (1) 30 mg/kg by mouth for a single dose; to (2) 10 mg/kg by mouth once daily for 3 days; to (3) 10 mg/kg by mouth on Day 1, then 5 mg/kg once daily on Days 2 through 5.
• Sinus infections: The typical dose is 10 mg/kg by mouth once daily for 3 days.
• Pneumonia: The typical dose is 10 mg/kg by mouth on Day 1, then 5 mg/kg once daily on Days 2 through 5.
• Strep throat and tonsillitis: The typical dose is 12 mg/kg by mouth once daily for 5 days.

Azithromycin (Zithromax) may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or supplements (including prescribed and over-the-counter medications, vitamins, and dietary or herbal supplements) that you are currently taking. The list below does not include all possible drug interactions with Azithromycin (Zithromax). Please note that only the generic name of each medication is listed below.

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. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

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.

Common Side Effects

Adults

• Diarrhea (4-5%)
• Nausea (3%)
• Stomach pain (2-3%)

Children

• Diarrhea (2-6%)
• Vomiting (1-6%)
• Stomach pain (1-3%)

Other Side Effects

• Gas
• Nausea
• Dizziness
• Headache
• Rash

Serious Side Effects

Contact your healthcare provider immediately if you experience any of the following.

• Serious allergic reaction: hives, rash, blisters, fever, swelling of the lips or tongue, difficulty breathing
• Worsening liver problems or liver failure: swelling of your stomach, yellowing of your skin or the whites of your eyes, confusion, dark or brown urine
• Abnormal heart rhythm (QT prolongation): chest pounding, trouble breathing, chest pain, feeling faint or lightheaded
• Infectious (C. difficile-related) diarrhea: rapid heart rate, foul-smelling diarrhea, fever, nausea, frequent bowel movements (even up to 15 times per day)

When do Azithromycin (Zithromax) possible side effects begin and end?

Time passed since treatment started:

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:

Less common

• Burning, redness, stinging, or other eye irritation

Rare

• Blistering, burning, crusting, dryness, or flaking of the skin
• Blurred vision
• Cough
• Decreased vision
• Discharge from the eye
• Fever
• Headache
• Hives or welts
• Itching, scaling, severe redness, soreness, or swelling of the skin
• Pain or tenderness around the eyes and cheekbones
• Painful irritation of the clear front part of the eye
• Shortness of breath or troubled breathing
• Skin rash
• Stuffy or runny nose
• Swelling of the face
• Swelling or puffiness of the eyes
• Tightness of the chest or wheezing

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:

Rare

• Change in taste
• Dry eyes
• Loss of taste

Pros and cons of Azithromycin (Zithromax)