Azithromycin

( Zithromax, Zithromax Z-Pak, Zithromax Tri-Pak )

Medically Reviewed by HaVy Ngo, Pharm.D.

Last Reviewed: Jun 10, 2022

Warnings

Azithromycin can cause serious health issues that are even higher risk for certain groups. Talk to your doctor or pharmacist about other options if you have any worries or concerns.

What are the risks of taking azithromycin?

Allergic reactions: Severe allergic reactions such as Stevens-Johnson syndrome (SJS) or anaphylaxis can happen. SJS presents with painful blisters all over the body, hives, and rash. Anaphylactic allergic reaction causes swelling of the face, throat, lips or tongue, and difficulty breathing. Call 911 or seek emergency medical care if this happens. Risk factors: existing allergy to other macrolide antibiotics such as erythromycin and clarithromycin.
Liver injury: This is a rare but life-threatening adverse reaction. Liver injury is presented with stomach pain, nausea, vomiting, jaundice, dark urine, and pale stools. Risk factors: ongoing liver problems or a history of liver disease.
QT prolongation: This is a rare but serious, life-threatening side effect of azithromycin. Other medications can also cause or worsen QT prolongation when taken in combination with azithromycin. Let your doctor know if you have any heart problems, and provide them with the list of all the medications you are taking, including prescription drugs, over-the-counter products, herbal supplements, and vitamins prior to initiation of azithromycin therapy. Risk factors: age of 65 or older; history of QT prolongation or arrhythmia; taking other medications that can cause QT prolongation.
Severe diarrhea: In some rare cases, a bacteria called Clostridioides difficile (commonly known as C. diff) causes severe diarrhea because azithromycin (like all other antibiotics) gets rid of the good bacteria in your gastrointestinal tract. C. diff diarrhea can be life-threatening and very contagious. Thorough handwashing with soap and water for at least 20 seconds is vital to stop the spread of C.Diff infection. If possible, use a different bathroom until you are better if you live with other people. Risk factors: age of 65 or older; previous C. Diff infection; recent hospitalization; weakened immune system; using multiple antibiotics; long-term use of antibiotics.
Worsening of myasthenia gravis: Taking azithromycin can worsen myasthenia gravis symptoms such as muscle weakness and difficulty breathing. Alternative treatment is recommended due to this problem. Your healthcare provider shall constitute medical advice that is most beneficial for your health. Risk factor: history of myasthenia gravis.
Syphilis: Syphilis can cause urethra and cervix infections, just like gonorrhea. It is important to know that azithromycin is not effective against syphilis. If you are being treated for a sexually transmitted infection, make sure that you are tested for syphilis too.

Speak to your doctor or pharmacist about other treatment options if you are at high risk for the above complications.

What should I tell my doctor before starting taking azithromycin?

You should let your doctor know:

If you are allergic to azithromycin or any of the ingredients in azithromycin tablets or oral suspension. You can ask your pharmacist for a list of the ingredients.
If you are allergic to other drugs in the same drug class such as clarithromycin, erythromycin, or telithromycin; or
If you ever had jaundice or liver problems from taking azithromycin in the past.

You should not take azithromycin if any of these above conditions is applicable to you.

Symptoms of an allergic reaction include difficulty breathing, hives, swelling of your lips, tongue, face, and throat. This is a medical emergency - Call 911 and seek medical care at the nearest hospital.

Tell you doctor if you have any of these conditions:

Liver disease
Myasthenia gravis
Kidney disease
Arrhythmia - heart rhythm disorder causing abnormal heartbeat
Hypokalemia - low level of potassium in blood; hypomagnesemia - low level of magnesium in blood. These electrolyte abnormalities increase your risk of QT prolongation
QT prolongation - long QT interval of the heart, in you or a family member

Even though azithromycin is not known to harm an unborn baby, it is best to tell your doctor if you are pregnant or have plans to get pregnant. Azithromycin passes into breast milk, so tell your doctor or your child’s pediatrician prior to taking azithromycin if you are breast-feeding.

Before starting azithromycin or any new medication, it is important to inform your doctor if you have any changes in your medication list or health history. Best practice is to print out your most updated medication list and bring it to every doctor appointment. Your doctor should be informed about all of the medications you are taking, including prescription drugs, over-the-counter products, herbal supplements, and vitamins. It is important to let your doctor know if you are taking any of the following medications:

Anticoagulants (blood thinner) such as warfarin (Coumadin)
Cyclosporine (Nioral)
Colchicine (Colcrys)
Digoxin (Lanoxin)
Arrhythmia medications such as amiodarone (Cordarone), dofetilide (Tikosyn), procainamide (Procanbid), quinidine, sotalol (Betapace), nelfinavir (Viracept), phenytoin (Dilantin).

Dose adjustment may be necessary, and your doctor will monitor you for the above side effects, and any other side effects that may occur.

Also, let your doctor know if you are taking antacids that contain aluminum hydroxide such as Mylanta, Maalox, and Tums. The extended-release formulation can be taken any time with antacids. For the immediate-release formulation, antacids should not be taken within 2 hours before or 2 hours after the administration of immediate-release azithromycin.

What proper medical care should I take while on azithromycin?

Be vigilant about monitoring for any side effects discussed previously, or any unusual changes in your body. Contact your healthcare provider if your symptoms persist or worsen.
Before surgery, let your doctor or dentist know if you are taking azithromycin or any other medications.
Azithromycin may cause live bacterial vaccines (typhoid vaccine) to be less effective. Unless directed by your doctor, refrain from getting any vaccinations while taking azithromycin.
Azithromycin makes you sunburn more easily. Avoid prolonged sun exposure or tanning beds. Use sunscreen with SPF 30 or higher and wear protective clothing when you are outdoors.
Keep all doctor and lab appointments. A blood test may be ordered by your doctor to see if the infection is cured.
Similar to other antibiotics, azithromycin is usually not refillable. Let your doctor know if you still have signs and symptoms of an infection.

What drugs can interact with azithromycin?

Anticoagulant (blood thinner) such as warfarin
Antacids
Digoxin
Clarithromycin
Drugs that can cause QT prolongation such as amiodarone, chloroquine, dofetilide, procainamide, quinidine.

This is not a complete list. Other drugs, including prescriptions, over-the-counter products, herbal supplements, and vitamins, may interact with azithromycin. Not all potential drug interactions are listed in this guide. It is highly recommended to keep a list of all the drug products you are using (prescriptions, over-the-counter products, herbal supplements, natural products, and vitamins), and share it with your doctor and pharmacist.

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