Zithromax medicine: Uses, dosage & usage


What is Zithromax?

Zithromax medicine containing Azithromycin content is indicated for use in cases of infections caused by susceptible bacteria of upper respiratory tract infections such as sinusitis, pharyngitis and tonsillitis, bronchitis , pneumonia , skin infections and soft tissue, otitis media, sexually transmitted infections.

The antibiotic Zithromax may also be used for purposes not listed in the medication guide.

Zithromax drug information

  • Drug Name: Zithromax.
  • Registration Number: VN-21930-19.
  • Active ingredient – ​​Concentration/content: Azithromycin – 200 mg/5ml.
  • Dosage form: Powder for oral suspension.
  • Packing: Box of 1 bottle of 600mg/15ml.
  • Expiry date: 24 months.

How does Zithromax work?

Zithromax is a macrolide antibiotic of the azalide group. The molecule is constructed by adding a nitrogen atom to the lactone ring of erythromycin A. The chemical name of azithromycin is 9-deoxy-9a-aza-9a-methyl-9a-homoerythromycin A.

The molecular mass is 749.0. The mechanism of action of azithromycin is based on inhibition of bacterial protein synthesis by binding to the 50S ribosomal subunit and inhibiting peptide translocation.

Indications for the use of Zithromax

The subjects that can use Zithromax drug include:

  • Patients infected with organisms that are still susceptible to Azithromycin and other macrolide antibiotics.
  • Indications Zithromax medicine for patients with respiratory infections such as pneumonia, acute bronchitis caused by bacteria such as Haemophilus influenzae, Pneumococcal Pneumococcus, Streptococcus bacteria, …
  • Patients with nasopharyngitis, otitis media, sinusitis, tonsillitis…
  • Patients with infections of the genital tract and urinary tract caused by bacteria that are not resistant to Macrolide antibiotics (including Erythromycin, Clarythromycin).

Contraindications to the use of Zithromax

Contraindicated in patients with hypersensitivity to azithromycin, erythromycin, to any antibiotic of the macrolide or ketolide family.

Dosage of Zithromax medicine

Dosage of Zithromax for adults

Zithromax is used to treat sexually transmitted diseases caused by Chlamydia trachomatis and Haemophilus ducreyi.

For susceptible strains of Neisseria gonorrhoeae, the recommended dose of Zithromax is a single dose of 1,000 mg or 2,000 mg of azithromycin in combination with 250 mg or 500 mg of ceftriaxone, depending on clinical guidelines.

For individuals allergic to penicillins or cephalosporins, the prescribing physician should refer to local treatment guidelines.

To prevent MAC infection in HIV patients, use Zithromax at a dose of 1,200 mg/time/week. According to the treatment guidelines, the drug should be continued until cellular immunity is restored (total CD4 count is maintained continuously more than 100 cells/microL).

For the treatment of DMAC in patients with advanced HIV, the recommended dose is 600 mg once daily. Co-administration of azithromycin with other antimycobacterial agents with in vitro MAC activity, such as ethambutol, is recommended at approved doses. The course of treatment should be continued until the symptoms are relieved and the bacteria are gone.

For other indications that can be taken orally, the total dose of Zithromax is 1,500mg for 3 days, 500mg per day. The same total dose can be substituted, but for 5 days, 500 mg on the first day and then 250 mg/day from day 2 to day 5.

For the elderly, use the same dose as adults. Elderly patients may be more susceptible to torsades de pointes than younger patients, who are at increased risk of cardiac arrest.

For patients with mild to moderate renal impairment (glomerular filtration rate – GFR 10 – 80 ml/min), no dose adjustment is required. Caution should be exercised when administering azithromycin to patients with severe renal impairment (GFR less than 10 ml/min).

Patients with mild to moderate hepatic impairment receive the same dose as for patients with normal liver function.

Dosage of Zithromax for children

The maximum recommended total dose of Zithromax for any treatment in children is 1,500 mg. In general, the total dose in children is 30 mg/kg, except for strep throat, which needs to be determined differently.

The total dose of 30 mg/kg should be administered as a single dose of 10 mg/kg daily for 3 days, or for 5 days as a single dose of 10 mg/kg on the first day, then 5 mg/kg daily from the first day. 2nd to 5th day.

If the treatment of children with acute otitis media can be replaced with a single dose of 30mg/kg. For streptococcal pharyngitis in children, azithromycin as a single dose of 10 mg/kg or 20 mg/kg for 3 days has been shown to be effective, but a dose of 500 mg/day should not be exceeded.

Zithromax Tablets 500mg are not suitable for children weighing less than 45kg. Safety and effectiveness in the prevention or treatment of MAC in children have not been established. Based on pharmacokinetic data in children, a dose of 20 mg/kg would be similar to an adult dose of 1,200 mg but with a higher peak Cmax.

How to take Zithromax?

Shake before use, powder for oral suspension: For 600 mg vials, add 9 ml of water; 900 mg vial, add 12 ml water, 1200 mg vial add 15 ml water.

For children weighing more than 15 kg, Zithromax should be carefully measured using an oral dosimeter and spoon suitable for children weighing 15 kg or more.

Tablets: Zithromax tablets should be swallowed whole. Before using the medicine, you should carefully read the instructions for use attached to the package or consult and use exactly as directed by your doctor. Absolutely do not arbitrarily stop taking the medicine or increase or decrease the dose without the consent of the doctor.

Many cases of abrupt discontinuation of the drug before the end of the course of treatment may lead to re-infection.

Taking many drugs at the same time will cause the effect of zithromax or low-dose drugs to be lost , or more dangerous, it will cause unwanted effects that are harmful to the user’s health.

Tell your doctor if you are taking any medicine and your condition does not improve or worsens for other more effective treatments.

Zithromax side effects

Get emergency medical help if you have signs of an allergic reaction to Zithromax: (rash, trouble breathing, swelling in your face or throat) or a serious skin reaction (fever, sore throat, burning sensation) in the eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, flu-like symptoms, muscle aches, severe weakness, unusual bruising or yellowing of your skin or eyes. This reaction may occur several weeks after you start using azithromycin.

Call your doctor right away if you have:

  • severe stomach pain, watery or bloody diarrhea;
  • fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out); or
  • liver problems–nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
  • Call your doctor at once if a baby taking Zithromax becomes irritable or vomits while eating or nursing.
  • Older adults may have more heart rhythm side effects, including life-threatening tachycardia.

Common side effects of Zithromax may include:

  • Diarrhea;
  • Nausea, vomiting, stomach pain;
  • Headache.

This is not a complete list of side effects and other possible side effects. Call your doctor for medical advice about side effects.

Zithromax drug interactions

Some drugs can affect the therapeutic effect of Azithromycin (Zithromax) and vice versa. Tell your doctor if you are taking medications such as:

  • Digoxin (medicine to treat heart failure).
  • Clarithromycin, Erythromycin (antibiotic of the same class).
  • Warfarin, Coumarin (drug to treat blood clots).
  • Antacids that contain magnesium or aluminum.

Do not use antacids containing magnesium or aluminum within 2 hours before or after using Azithromycin (Zithromax) such as: Gaviscon, Maalox, Phospholugel … These drugs may make Azithromycin (Zithromax) ineffective.

Kidneys while using Zithromax


As with erythromycin and other macrolides, rarely serious allergic reactions, including angioedema and anaphylaxis (rarely fatal), and skin reactions including Stevens Johnson syndrome and toxic epidermal necrolysis (rarely fatal).

Some reactions to Zithromax have caused recurrent symptoms and require longer monitoring and treatment. If an allergic reaction occurs, the drug should be discontinued immediately and appropriate therapy instituted.

Liver toxicity

Since the liver is the major route of elimination for azithromycin, Zithromax should be used with caution in patients with liver disease.

Abnormal liver function, hepatitis, obstructive jaundice, hepatic necrosis and liver failure have been reported, some of which have been fatal. When these signs and symptoms are observed, Zithromax should be discontinued immediately.

Use of drugs derived from ergot (Ergot)

In patients taking drugs of the ergot origin, ergot toxicity is increased when used in combination with macrolide antibiotics. There are no data on the potential for an interaction between ergot and azithromycin.

However, because ergotin toxicity is theoretically possible, the combination of ergot derivatives with Zithromax is not recommended.


As with any antibiotic, it is important to monitor for signs of superinfection with non-susceptible organisms, including fungi.

Clostridium difficile-associated diarrhea

Clostridium difficile-associated diarrhea (CDAD) has been reported with use with most antibacterial agents, including azithromycin, and the severity can range from mild diarrhea to colitis leading to dead.

Treatment with antibacterial agents alters the natural microbial population of the gut leading to overgrowth of c. difficile.

Clostridium difficile produces toxins A and B that contribute to the development of CDAC. Toxic strains of C.difficile are responsible for increased morbidity and mortality, as these infections can be difficult to treat with antibiotic therapy and may require colectomy.

CDAD should be considered in all patients who develop diarrhea following antibiotic therapy. A careful history should be taken because CDAD has been reported more than 2 months after antibiotic therapy.


In patients with severe renal impairment (glomerular filtration rate <10 ml/min) a 33% increase in Zithromax plasma concentrations was observed.


Precautions for diabetics: 5ml of the reconstituted suspension contains 3.87g of sucrose. Because the drug contains sucrose (3.87g/5ml of the reconstituted suspension), do not use the drug for patients with fructose intolerance (intolerance, hereditary fructose), glucose-galactose malabsorption or enzyme deficiency. sacharase-isomaltase.

Prolong QT interval

Prolongation of cardiac repolarization and prolongation of the QT interval, which increases the risk of arrhythmias and torsades de pointes, have been observed with the use of macrolides, including azithromycin.

Prescribers should consider the risk of potentially fatal QT prolongation when weighing the risks and benefits of Zithromax for high-risk groups including:

  • Patients with congenital or acquired QT prolongation
  • The patient is currently taking drugs that prolong the QT interval, such as class IA and class III antiarrhythmics: antipsychotics, antidepressants, and duroquinolone.
  • Patients with electrolyte disturbances, especially in cases of hypokalaemia and magnesium in the blood.
  • Patients with bradycardia, arrhythmia or heart failure.
  • Elderly: The elderly may be more sensitive to concomitant effects on the QT interval.


Exacerbations of systemic myasthenia gravis and onset of myasthenic syndrome have been reported in patients treated with azithromycin.

For pregnant & lactating women

  • Not recommended for pregnant women unless absolutely necessary.
  • The drug passes into breast milk, so it should not be used by nursing women unless absolutely necessary.

How much does Zithromax cost?

Price of antibiotic Zithromax 200mg/5ml bottle 15ml: 128,000VND/bottle.

How to store Zithromax?

  • You should store the medicine at room temperature, in a cool, dry place, away from direct sunlight.
  • You should not store the medicine in the refrigerator.
  • Keep the medicine out of the reach of children.
  • Do not throw medicine down the toilet or plumbing.

Disclaimer: Index-China goal is to provide readers with relevant and up-to-date information. However, because drugs interact differently from person to person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always talk to your doctor or healthcare provider about possible interactions with all prescription medications, vitamins, herbs, and supplements, and over-the-counter medications you’re taking.


See also: https://index-china.com/zithromax-medicine/

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