Azithromycin (Oral)

Azithromycin is an oral route, macrolide antibiotic drug prescribed for the treatment of several types of bacterial infections in adults and children.


Azithromycin is a generic antibiotic medication used in the treatment of certain conditions caused by infectious bacteria. The 'œbroad-spectrum' nature of this antibiotic makes it a preferred medication for treating a wide range of bacterial infections. Respiratory, skin, and ear infections, and some sexually transmitted diseases (STD's) are among those commonly treated.

The drug is available in the US by doctor's prescription only and is sold under the brands Zithromax, Zma, Zithromax Tri-Pak, and Zithromax Z-Pak. It comes in the form of a tablet and powder for oral and extended-release suspension. The medicine works by killing and preventing the growth and spread of the infection-causing bacteria.
Patients must complete the full course of the antibiotic even if they feel better before finishing. Otherwise, the infection may return or spread and become worse.

The use of Azithromycin is prohibited in certain children and should be used with caution in elderly adults and pregnant or breastfeeding women. Patients with medical problems that could increase the risk of serious adverse interaction should not use this drug. The drug is not recommended for patients with heart problems due to the risk of serious cardiovascular complications, and even death.

This medicine is a suitable alternative for people with bacterial infections who are allergic to the antibiotic, penicillin. It may also be used for treating other conditions not discussed in this article. But patients with viral infections, e.g., colds and flu, cannot be treated with this medicine.

Common infections treated

Some common bacterial infections treated are:

Before using Azithromycin

Before starting treatment with this antibiotic, it is important for you to have a thorough discussion with your doctor, so you can understand how this medicine works and how it can affect you. Disclose the use of all prescription and over-the-counter (OTC) medicines you are taking or plan to take during treatment.

If you are allergic to certain foods, preservatives, animals or dyes make sure you mention this. This information will help your doctor to determine if this medicine is safe for use. In discussing your medical history, make sure you tell your doctor if you are pregnant or breastfeeding or have or had the following conditions. They may be affected by your use of the medication:

  • a heart rhythm disorder
  • a heart failure
  • low levels of potassium or magnesium in your blood
  • diabetes or fructose intolerance
  • kidney disease
  • Myasthenia Gravis (a muscle disorder)
  • long QT syndrome (in you or a family member)
  • liver disease

Azithromycin should not be used to treat the following people:

  • Patients allergic to the medicine
  • Those allergic to macrolide or ketolide antibiotics, such as erythromycin, telithromycin, or clarithromycin
  • Patients who developed jaundice or liver problems from taking Azithromycin
  • Children under 6 months of age

Pediatrics: The safety and efficacy of using the medicine in children have not been established as it relates to the treatment of pneumonia or sinusitis in children younger than 6 months. The oral suspension and tablet forms of the drug may not be safe for use in treating tonsillitis or pharyngitis in children under the age of 2.

Geriatrics: Azithromycin should be used with caution in elderly patients because they are more likely to develop heart problems.

Pregnant and breastfeeding women: There are no conclusive findings of possible harm to an unborn baby. There is minimal risk to a breastfeeding infant exposed to the medicine through breast milk. Therefore, the use of the drug in
pregnant or breastfeeding women should be determined by a doctor.

Conditions Treated

  • Bacterial infections

Type of Medicine

  • Macrolide Antibiotic

Side Effects

With most medicines, side effects are expected as the medicine performs its function in the body. Some side effects may occur that may or may not need medical attention. Stop using Azithromycin and call your doctor right away if you experience any of the following side effects, as they may be serious:

Commonly occur

Less commonly occur

  • drying, cracking, crusting or scaling of the skin
  • itching, irritation, reddening or blistering of the skin
  • swelling
  • fever

Rarely occur

  • chest pain
  • dark urine
  • dizziness
  • chills
  • pain in the stomach or abdomen
  • sense of discomfort in the stomach
  • indigestion
  • drowsiness
  • earache
  • loss of appetite
  • trouble sleeping
  • runny nose
  • yellow eyes or skin
  • burning sensation while urinating
  • irregular or slow heartbeat
  • vomiting blood
  • change in the color of the stool (light, bloody, black or tarry)
  • dry or sore throat
  • headache
  • body aches or pain
  • trouble breathing
  • gas or flatulence that is excessive
  • coughing (dry or with mucus)
  • stuffy nose
  • difficulty swallowing
  • peeling of the skin
  • blistering sensation on the skin
  • difficult or painful urination
  • fast, irregular or unusual heart rhythm
  • redness or swelling in the ear
  • wheezing
  • nausea or vomiting
  • rash
  • general feeling of sickness, tiredness or weakness
  • joint or muscle pain
  • swelling of the sex organ
  • swelling of the face, ankles, hands, feet or lower legs
  • hive-like swelling of the face, lips, tongue, eyelids, throat, hands, legs or feet
  • bad breath
  • change in tone of voice
  • red, irritated eyes
  • shortness of breath
  • shivers
  • ulcers, sores or white lesions on the lips or in the mouth
  • feeling of discomfort in the stomach
  • swelling or tenderness of the glands in the neck
  • itching about the body
  • vaginal itching or discharge
  • unusual bleeding or bruising
  • congestion
  • problems hearing or a ringing in the ear
  • change in the sense of taste or smell

The following are some of the possible side effects that may occur, but may not need medical attention:

Rarely occur

  • unable to sleep
  • white patches in the mouth, tongue or throat
  • feeling as if you are spinning
  • feeling full
  • upset stomach
  • dry mouth
  • unusual crying
  • belching
  • acidic or sour stomach
  • heartburn
  • changes in the color of the tongue
  • mood swings
  • unusual anger or aggressiveness
  • mental depression
  • dysphoria
  • hyperventilation
  • pain during intercourse
  • sore mouth or tongue
  • paranoia
  • restlessness
  • shakiness
  • euphoria
  • nervousness
  • muscle weakness or loss of strength
  • vaginal discharge with or without odor
  • rash with flat or raised lesions on the skin
  • tingling or sense of prickling ('œpins and needles') of the skin
  • sensation of numbness, itching, burning, or crawling of the skin

Incidence unknown

  • blurry vision
  • clay-colored stools
  • confusion
  • unusual noise or sense of buzzing or ringing in the ear
  • reduced amount of urine
  • bloating
  • hearing loss
  • unable to hear clearly
  • cramps or tenderness in the abdominal or stomach
  • depression
  • severe diarrhea that may be watery or blood stained
  • bleeding gums
  • lightheadedness, dizziness or faintness when getting up suddenly from a sitting or lying position
  • fainting
  • constipation
  • blood stained urine or stool
  • hives
  • excessive thirst
  • lethargy
  • decreased frequency in urination
  • pain in the side or lower back
  • rapid weight gain
  • twitching of the muscles
  • hostility
  • pains in the abdomen, stomach or sides that feel as if it is radiating to the back
  • irritability
  • tiny red spots on the skin
  • swelling or puffiness of the eyelids, face, lips or tongue or around the eyes
  • seizures
  • stupor
  • pale skin
  • unusual weight loss

This is not an all-inclusive list of possible side effects. Also, some of them that occur may not require medical attention. They generally go away on their own as the body adjusts to the treatment.

If they become worse or bothersome, speak with your healthcare professional or doctor. You may also ask for a complete list of all possible side effects and ways to prevent or reduce them. Side effects may be reported to the FDA at 1-800-FDA-1088.


Adults and children can be treated with Azithromycin. Dosage depends on age, the condition being treated, how severe the condition is, the patient's reaction to the first dose, and the duration of treatment. The presence of any other medical condition is another factor considered in setting the dosage.

Do not start or stop using or change the dose of the medicine without approval from your healthcare professional. The following is an average recommended dosage guide. Your dose and how often you take it will be given to you by the pharmacist. Follow those instructions and any other given to you by your doctor and the prescription label.

Tablets or oral suspension:

Suspensions (including extended-release) are Azithromycin powder mixed with water.

For treatment of infections

Adults: Take a single dose of 500 to 2000 milligrams (mg). Additional doses of 250 to 500mg, once a day for several days may be prescribed depending on the type of infection being treated.

Children and Infants (age 6 months and older): Dose is determined by a doctor based on age and body weight.

Infants (age 6 months and younger): This medication is not recommended for children under 6 months of age. In exceptional cases, and if the benefits outweigh the risks, dose may be determined by a doctor.

For treatment of pharyngitis or tonsillitis:

Adults: Day 1: take 500 milligrams (mg) at once, taken as a single dose. Follow up with a 250mg dose on Day 2 through Day 5.

Children (Age 2 years and older): Dose is determined by a doctor based on age and body weight.

Children (Age 2 years and younger): Use and dose must be determined by your doctor.

Extended-release suspension:

For treatment of pneumonia

Adults: Take 2 grams (g) at once as a single dose.

Children (weighing 75 pounds (34 kg) or more): Take 2 g once as a single dose.

Children and infants (age 6 months and older weighing less than 75 pounds (34 kg): Dose must be determined by a doctor.

For treatment of sinusitis

Adults: Take 2 grams (g) at once as a single dose.

Children: Use and dose must be determined by your doctor.

Additional dosage information

  • The Azithromycin dosage for any other type of bacterial infection may be determined by your doctor.
  • The medicine may be taken with or without food depending on if it is being taken as a tablet, oral liquid suspension or extended-release suspension.
  • Always shake the suspension well just before you are ready to take a dose. Use a special dose-measuring spoon or medicine cup to measure the liquid. A regular eating spoon may not measure the dose accurately. Ask your pharmacist for one if it is not included in the medicine packet.
  • The oral suspension medicine should be taken within 12 hours after it was mixed with water.
  • It is recommended that the extended-release suspension be taken on an empty stomach or at least 1 hour before or 2 hours after a meal.
  • Throw away any remaining medicine prescribed for your child after you give the dose.
  • If within one hour of taking the extended-release suspension you or your child vomits, do not repeat the dose. Call your doctor right away to find out what to do next.

Missed Dose

If you miss a dose of Azithromycin, take it as soon as possible. If it is too close to the time for your next scheduled dose, wait and take the next dose on time. Do not take an extra dose to make up for the missed dose.


There is reportedly no data on Azithromycin overdose. If an overdose does occur, call 911 or the Poison Control Center at 800-222-1222 and get urgent medical care.


Other medications (prescription, non-prescription), vitamins, nutritional supplements, and herbal products may interact with Azithromycin. Medical problems (or history of), foods and other agents, such as alcohol or tobacco, may also cause interactions. When interaction occurs, it may adversely affect the body or increase the risk for serious side effects.

Tell your doctor of all your medicines. Ensure you also tell any other healthcare provider who will be treating you or performing surgeries while you are taking this antibiotic.

In exceptional cases, medicines that may interact with Azithromycin may still be prescribed for you because it is best for your health. Your doctor may change other medicines you take or adjust your dose to accommodate them in such cases.

The medicines on the following list are not recommended to be used while using this antibiotic. There are other medicines that may interact, but these were chosen based on their potential to cause a significant interaction. Your doctor may still decide to treat you while taking necessary precautions.

  • Ergonovine
  • Sparfloxacin
  • Bepridil
  • Ergoloid Mesylates
  • Amifamipridine
  • Ergotamine
  • Methylergonovine
  • Thioridazine
  • Cisapride
  • Piperaquine
  • Saquinavir
  • Dihydroergotamine
  • Amisulpride
  • Terfenadine
  • Methysergide
  • Ziprasidone
  • Dronedarone
  • Pimozide

Here is a list of medicines that are not usually recommended for use during any treatment with Azithromycin. However, their use may be required and prescribed in some cases. To ensure the co-combination treatment works effectively, your doctor may change the dose or how often you use any of the medicines.

  • Vincristine
  • Afatinib
  • Lumefantrine
  • Digoxin
  • Fluconazole
  • Amiodarone
  • Promethazine
  • Clozapine
  • Anagrelide
  • Buserelin
  • Chlorpromazine
  • Histrelin
  • Clomipramine
  • Dabrafenib
  • Lopinavir
  • Bretylium
  • Dasatinib
  • Ondansetron
  • Desipramine
  • Pazopanib
  • Domperidone
  • Alfuzosin
  • Acecainide
  • Doxorubicin
  • Efavirenz
  • Degarelix
  • Erythromycin
  • Ciprofloxacin
  • Escitalopram
  • Fingolimod
  • Chloroquine
  • Tedisamil
  • Flecainide
  • Gemifloxacin
  • Amitriptyline
  • Prochlorperazine
  • Goserelin
  • Imipramine
  • Asenapine
  • Doxorubicin Hydrochloride Liposome
  • Aripiprazole
  • Lapatinib
  • Granisetron
  • Apomorphine
  • Sodium Phosphate, Monobasic
  • Droperidol
  • Haloperidol
  • Ibutilide
  • Fluoxetine
  • Iloperidone
  • Clarithromycin
  • Sodium Phosphate, Dibasic
  • Donepezil
  • Amoxapine
  • Ivabradine
  • Ketoconazole
  • Delamanid
  • Leuprolide
  • Voriconazole
  • Halofantrine
  • Methadone
  • Levofloxacin
  • Citalopram
  • Topotecan
  • Norfloxacin
  • Azimilide
  • Sematilide
  • Octreotide
  • Toremifene
  • Mefloquine
  • Cholera Vaccine, Live
  • Paliperidone
  • Moxifloxacin
  • Nortriptyline
  • Ofloxacin
  • Trifluoperazine
  • Panobinostat
  • Simvastatin
  • Hydroxychloroquine
  • Gonadorelin
  • Morphine
  • Pasireotide
  • Hydroxyzine
  • Morphine Sulfate Liposome
  • Pentamidine
  • Dolasetron
  • Nafarelin
  • Pimavanserin
  • Metronidazole
  • Astemizole
  • Disopyramide
  • Gatifloxacin
  • Tetrabenazine
  • Dofetilide
  • Quinine
  • Pitolisant
  • Crizotinib
  • Procainamide
  • Mifepristone
  • Propafenone
  • Solifenacin
  • Protriptyline
  • Quetiapine
  • Nilotinib
  • Trimipramine
  • Arsenic Trioxide
  • Quinidine
  • Ranolazine
  • Salmeterol
  • Pixantrone
  • Sevoflurane
  • Vincristine Sulfate Liposome
  • Deslorelin
  • Sodium Phosphate
  • Vemurafenib
  • Sulpiride
  • Perflutren Lipid Microsphere
  • Sunitinib
  • Tacrolimus
  • Vardenafil
  • Telithromycin
  • Zuclopenthixol
  • Sotalol
  • Triptorelin
  • Vandetanib
  • Warfarin
  • Posaconazole
  • Vinflunine
  • Trazodone
  • Sorafenib

Even though it may be the best treatment for you, using any of the following drugs with Azithromycin may increase the risk of certain side effects. If you must use any of them, your doctor may change the dose or how often you use it during treatment with this antibiotic.

  • Rifabutin
  • Theophylline
  • Nelfinavir
  • Atorvastatin
  • Lovastatin

Other Interactions

Food, alcohol and tobacco: Ask your doctor what foods you should avoid while taking the treatment as certain foods may cause an interaction. Similarly, the use of alcohol or tobacco during treatment may adversely interact with the drug.

Allergies: Patients allergic to any macrolide or ketolide antibiotic such as erythromycin should not be treated with Azithromycin. Tell your doctor about any of these allergies.

Other medical problems

Azithromycin is not recommended for use in the patients with these medical problems:

  • liver disease triggered by prior use of azithromycin
  • low potassium in the blood' uncorrected (a condition known as Hypokalemia)
  • low magnesium in the blood' uncorrected (a condition known as Hypomagnesemia)
  • slow heartbeat (a condition known as Bradycardia)

Use with caution in patients with the following conditions, as it may make the conditions worse:

  • heart disease
  • ongestive heart failure
  • heart rhythm problems, such as prolonged QT interval, or history of
  • Myasthenia Gravis (muscle weakness disorder)
  • diarrhea

Use with caution in patients with the following conditions, as the side effects may be increased because of slower removal of the medicine from the body:

  • liver disease
  • kidney disease (severe)

Azithromycin (Zithromax) is not recommended to treat pneumonia in patients with these conditions:

  • a weak immune system
  • any pre-existing infections, including an infection of the blood (Bacteremia)
  • Cystic Fibrosis
  • a weakened physical condition
  • infections, nosocomial or hospital-acquired


  • Use Azithromycin only when prescribed by a doctor specially for you.
  • Carefully follow all directions given by the doctor, pharmacist, prescription label and patient information leaflet provided with the medicine.
  • Do not use this medicine if it was prescribed for someone else, and do not share with anyone else even if you both have similar symptoms.
  • Do not take other medicine to treat symptoms of side effects without first talking with your doctor. They may be unsafe to use together with Azithromycin or increase the risk of serious side effects.
  • Do not take antacids that contain aluminium or magnesium within 2 hours before or after you take this antibiotic. Examples of such antacids are Mylanta, Pepcid, Rolaids and Milk of Magnesia. They can interfere with the body's absorption of the medicine.
  • Take your dosage exactly as prescribed. Measure your dose accurately, as directed, and do not take less or more of the medication.
  • Take all your doses and take them on time until the treatment cycle comes to an end.
  • Avoid skipping doses or stopping the treatment prematurely, even if you feel better. Doing so may cause the infection to spread, expose you to the risk of further infections, or make your body resistant to antibiotics, including this drug.
  • Do not keep or use expired medicine. Throw away unused medicine as soon as you complete the course of treatment. For suspensions, discard remaining medicine after the last day indicated on the prescription label (usually after 5 days for oral suspension).
  • Discard unused extended-release suspension at least 12 hours after water has been added to the powder.
  • Discard all medications, tablets and suspensions in a manner that is safe, as directed by your healthcare professional or doctor or the patient information leaflet. You may also ask your local waste disposal company about safe disposal of your medicine and containers.
  • Patients using Azithromycin may get sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) during exposure to sunlight. Avoid tanning beds.

If you still feel unwell after fully completing your treatment with the antibiotic, call your doctor and make another appointment to follow up.


Keep Azithromycin stored safely and out of the reach of children and pets. Keep the medicine in a closed container and store at room temperature or refrigerate as directed. Avoid exposing it to heat, moisture, and direct light.

You may store the oral suspension at room temperature or in the refrigerator. Keep from freezing. Do not refrigerate or freeze the extended-release suspension.


Azithromycin tablet, oral liquid, and extended-release suspension are safe to use. They generally produce the desired results when used strictly according to the directions given.

This 'œbroad-spectrum' drug is known to effectively treat a wide range of bacterial infections in adults and children. They include serious infections such as pneumonia and sinusitis. It is also suitable for patients who are allergic to other antibiotics, particularly penicillin.

The safety and efficacy of the medicine are well established for patients who are generally healthy, with minimal restrictions for pregnant and breastfeeding women. Children 6 months of age and older may be safely treated with the drug, as determined by a doctor. Patients should use this medicine only if the benefits outweigh the risks.

There is, of course, a non-exhaustive list of side effects caused by the medicine. Most of them are rare or fall into the class of side effects with incidence unknown. Many of the effects are gastrointestinal in nature and include nausea, vomiting, and abdominal discomfort. Some side effects are considered serious and usually require medical attention.

Azithromycin interacts with co-existing medical problems which can affect the way the medicine is intended to work. Interactions can also increase the risk for serious side effects or risk of cardiovascular death in heart patients. Certain medications can be used while taking Azithromycin even though they may interact, while some others should not be used.

The use of antacids is also not recommended while taking this drug because they tend to interfere with its absorption in the body.

To get the best out of the treatment with Azithromycin, it is critical that patients take their doses regularly and on time. Patients are also required to complete the treatment cycle before discontinuing use of the medicine, even if they feel better before the treatment ends.

Failing to strictly follow the directions to take and complete the course of the antibiotic may cause the infection to spread or become worse. Furthermore, the bacterial infection may become resistant to Azithromycin treatment or treatment with other antibiotics.