Last Updated December 20th, 2021

Therapeutic Indications

Azithromycin is an antibiotic which specifically comes under the class of macrolide antibiotics. This medicine can effectively fight bacterial infections. This is why it is called an antibacterial. Anti-bacterials work by inhibiting the growth of bacteria or completely destroying them.

Azithromycin is available for oral intake and is manufactured as a tablet, extended-release suspension, and suspension. Eye drops of azithromycin are also available. The healthcare provider suggests a suitable form of medicine after evaluating the patient. This drug can also be administered intravenously, like an injection. It can also be used as a combination with other antibiotics.

Azithromycin is available in its generic form as well as brand name version, Zithromax. Oral tablets are available in both forms- generic and brand name. Azithromycin is not used to treat infections triggered by viruses.

Facts about Azithromycin

PLEURISY lungsAzithromycin works well to treat respiratory infections such as sinusitis, bronchitis, pneumonia as well as chronic obstructive pulmonary disease (COPD). It is also used to fight whooping cough (pertussis). It cannot fight viral infections such as flu and the common cold.

Azithromycin can also treat sexually transmitted infections, as well as ear and skin infections.

Azithromycin treats the following bacterial infections:

  • Severe Sinusitis caused by Moraxella Catarrhalis
  • Gonorrhea
  • Gonorrhea of the Cervix and urethra and rectum and throat
  • Skin Infection caused by Streptococcus Agalactiae Bacteria and Staphylococcus Aureus Bacteria
  • Pneumonia
  • AIDS with Toxoplasmosis
  • Whooping Cough
  • Chancroid
  • Chlamydia Trachomatis
  • Chronic bronchitis
  • Middle Ear infection caused by Influenzae Bacteria and Moraxella Catarrhalis and S. Pneumoniae Bacteria
  • Infection in pelvic region of women
  • Pneumonia triggered by Streptococcus pneumonia
  • Lyme disease
  • Strep Throat and Tonsillitis
  • Mycobacterium Avium Bacterial Infection
  • Intestinal Infection
  • Acute Bacterial Infection of the Sinuses
  • Offset risk of Traveller’s Diarrhea
  • Offset Bacterial Infection of Heart Valve

Do I need a prescription?

Azithromycin was earlier prescription only medicine. It was in 2008 that the Medicines and Healthcare products Regulatory Agency gave the nod to reclassify Azithromycin as an over the counter oral antibiotic. It is now available OTC to treat asymptomatic chlamydia infection and is the first ever antibiotic that changed from being a  prescription-only medicine to pharmacy medicine status.

As an OTC medicine azithromycin is available for people above 16 years with chlamydia. The drug is available OTC for the sexual partners too.


copd symptomsJust like most antibiotics, they begin to work soon after it is consumed. However, you may begin to feel a reduction in symptoms after two or three days. The effectiveness of the antibiotic like azithromycin depends on dosage, nature of infection and severity. The healthcare provider decides the number of days it should be taken as well as fixes the strength of the medication. Doctors usually prescribe antibiotics for 7 days and in some cases increase to 14 days.

Once you have started taking an antibiotic the antibiotic course has to be completed. Even though you might find relief from the symptoms, it is good to complete the course so that it is possible to eliminate the infection. Further, completing the entire regimen offsets the risk of antibiotic resistance. It is always good to consult with the healthcare provider before stopping the antibiotic abruptly.

Forms and strengths

Both the generic and brand name versions of azithromycin oral tablet are available in strengths of 250 mg, 500 mg, and 600 mg.

For community-acquired pneumonia

Adult dosage: 500 mg as a single dose on day 1. This is followed by 250 mg once per day for the next four days.

Child dosage (ages 6 months to 17 years): It is a five-day course split up as the following.

  • 10 mg per kg of body weight single dose for the first day.
  • Follow this by 5 mg/kg once a day for the next four days.

Children below 6 months of age are not administered this drug.

For skin infections

Adult dosage for the above infection is fixed at 500 mg to be consumed as a single dose on day 1. This could be followed up with a 250 mg dose once for the next 4 days.

For bronchitis, sinusitis

Drug is not recommended for children below 6 months. The dosage for children from 6 months to 17 years is 10 mg/kg of body weight once per day for three days.

 Adult dosage (ages 18 years and older)

The dosage is usually set at 500 mg to be consumed once per day for three days. Alternatively,the 500mg dosage on day 1 could be followed up with a 250 mg dose for the next four days.

For genital ulcer disease

Adult dosage for a genital ulcer is a single 1-gram dose.

For urethritis and cervicitis

The adult dosage for this infection not triggered by gonorrhea is a single 1-gram dose.  If the infection is caused by gonorrhea, a single 2-gram dose is prescribed.

Severe middle ear infection

Child dosage (ages 6 months to 17 years):30 mg/kg of body weight to be administered as a single dose. Alternatively, the specialist could also advise a five-day course of 10 mg/kg of body weight on day 1, followed by 5 mg/kg per day for the succeeding four days. Doctors do not prescribe this drug to children below the 6 months.

For Mycobacterium avium complex disease, the prophylactic treatment involves taking the drug at a typical dosage of 1200 mg per week.

For pharyngitis or tonsillitis

Adult dosage: 500 mg as a single dose on the first day of a five-day course. Next four days it is 250 mg once per day

Child dosage (ages 2 to 17 years): Five-day course with dosage fixed at 12 mg/kg of body weight once per day for five days.

This drug should not be administered for children below 2 years

Chemical composition

Azithromycin is a white crystalline powder. It’s brand name version, Zithromax in tablet form contains azithromycin dehydrate that is equal to 600 mg azithromycin.  The tablet also contains pregelatinized starch, dibasic calcium, sodium croscarmellose, phosphate anhydrous, sodium lauryl sulfate, magnesium stearate. The tablet has a film coat which contains lactose, triacetin, titanium dioxide, and hypromellose.

ZITHROMAX for oral suspension contains azithromycin dihydrate and also contains sodium phosphate tribasic, sodium phosphate tribasic and colloidal silicon dioxide.

Mechanism of action

Azithromycin being a macrolide antibiotic works well to impede bacterial protein synthesis, Azithromycin collects impressively in cells and more so in phagocytes. It targets the infected spots aggressively in higher concentrations. This drug is therefore used effectively to treat bacterial infections. The drug’s immunomodulatory influence, especially in acute inflammatory disorders, is worth a mention.


Azithromycin interactions with other medications cannot be ignored. It is to be noted that azithromycin may interact with other medications such as vitamins, herbs that you could be taking. Drug interactions reduce the effectiveness of the drug and sometimes even make the drug harmful, leading to side effects.

To understand the interactions, it is very important to disclose details of all the drugs you are consuming to your healthcare provider.

  • Azithromycin comes with many warnings about potential interactions with medicines as well as serious allergic reactions. Consumers need to remember that taking drug azithromycin along with other medications can increase the risk of side effects.
  • For instance, atients who are on drug warfarin need to watch out. Azithromycin, when taken along with warfarin, can exacerbate the risk of bleeding. It is important that such patients are monitored closely by healthcare specialists to offset grave drug interactions.
  • Those who are on Nelfinavir also need to exercise caution as azithromycin and nelfinavir combo can increase the risk of liver problems. It can also cause problems with hearing.
  • Azithromycin can cause allergic reaction in some people. If you experience breathing trouble or any inflammation of the tongue or throat, you should consult the medical specialist without delay. completely avoid taking this drug if you have suffered an allergic reaction with the drug at any point.
  • Victims of certain health conditions like irregular Heart rhythm and myasthenia gravis need to be careful while taking this drug as it can worsen the symptoms. Those with an abnormal heartrhythmneed to know that certain cases of azithromycin drug interaction can also prove fatal.
  • Azithromycin should be an SOS drug for pregnant women or lactatingmothers which means it should be taken only when absolutely necessary.  Animal studies have not pointed to any high risk to the fetus.  Of course in-depth research is need of the hour to establish its risks on the growing human fetus.
  • This drug may cause side effects to the child so breast feeding mothers need to be extra careful.

Side effects

Side effects of Azithromycin oral tablet are listed below. While some are relatively common side effects, the serious ones need extra care and precaution.

Some of the common side effects are:

  • Stomach pain
  • Nausea
  • Diarrhoea

Some of the rare side effects of the drug cold manifest  as

  • Stomach upset
  • Bloating/gas
  • Vomiting
  • Headache
  • Dizziness
  • Rashes
  • Infection in the private parts

The side effects usually disappearwithin a few days. If they persist, it is good to seek the opinion of your pharmacist or medical specialist.

Serious side effects

Some of the serious side effectswhich need immediate treatment include:

  • Discoloured and dark urine
  • Extreme fatigue and weakness
  • Skin turns apple and yellow
  • Whites of the eyes turn yellow
  • Loss of appetite
  • Upper stomach pain
  • Breathing problems
  • Hives
  • Swelling of throat, lip, tongue, face
  • Hives
  • Severe skin reactions for instance red skin

It is imperative to stop taking this drug if the side effects are severe. Any allergic reaction could get worse or even turn life threatening if the drug is continued . It is best to approach theclosest emergency room to avoid further damage.

What to do if you skip a dose

Azithromycin should be consumed as prescribed and obviously if does are skipped it may not have the desired effect.  Plus skipping doses comes with associated risks.

If doses are missed then the drug will not work efficiently. The infection may also worsen and the antibiotic may not work if drug resistance has set in. For this drug to work efficiently a certain requisite amount of the drug needs to be present in the body.

In case you skip a dose, you can take the dose the moment you remember. But if this is close to the next dose, consume only one dose. Taking doses at a time to make up for a skipped dose is not advisable as it can lead to overdose and associated side effects.


Handling azithromycin overdose is best if you seek emergency medical assistance as there could be alarming levels of azithromycin in the body. This could trigger irregular heart rhythm and liver damage.

Substitutes for the drug

Some of the substitutes for Azithromycin are listed below:

  • Augmentin (amoxicillin / clavulanate)
  • Amoxi
  • Cipro (ciprofloxacin)
  • Vibramycin
  • Keflex
  • Cleocin
  • Levaquin
  • Bactrim

Generic brand names of Azithromycin


Different Brands and Manufacturing Companies of the drug

Several companies manufacture generic and branded versions of Azithromycin. Some of the names of the brands are listed below

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