Generic name: Azithromycin.

Zithromax is a macrolide antibiotic. It prevents bacteria from multiplying and growing.

Quick Facts About Zithromax


Used to treat a wide variety of bacterial infections, including skin infections; upper and lower respiratory tract infections such as strep throat, tonsillitis, and pneumonia; and sexually transmitted infections of the cervix or urinary tract.

Zithromax Dosage

Take on an empty stomach, at least 1 hour before or 2 hours after a meal. Do not take with food or antacids containing aluminum or magnesium, such as Di-Gel, Gelusil, Maalox, and others. Finish the entire prescription.

  • Usual adult dose: 500 milligrams in a single dose on day 1 of treatment, followed by 250 milligrams in a single dose each day for 4 days. Maximum amount taken should be 1.5 grams. For nongonococcal urethritis and cervitis due to chlamydia — a single gram (1,000 milligrams) taken one time only. Now comes in powder for reconstitution.
  • Usual child dose: for children 16 and over — prescribed adult dose. Not generally prescribed for children under 16 years.
  • Missed dose: take as soon as possible, unless it is the next day. In that case, do not take the missed dose; go back to regular schedule. Do not double doses.

Zithromax Side Effects

Overdose symptoms:

no specific information available. If you suspect an overdose, immediately seek medical attention.

More common side effects: abdominal pain, diarrhea or loose stools, nausea, vomiting.

Less common Zithromax side effects: blood in the stools, chest pain, dizziness, drowsiness, fatigue, gas, headache, heart palpitations, indigestion, jaundice (yellowing of the skin and whites of the eyes), kidney infection, light sensitivity, rash, severe allergic reaction including swelling (as in hives), sleepiness, vaginal inflammation, vertigo, yeast infection.


Important to check with your doctor before using antacids containing aluminum or magnesium, such as Maalox and Mylanta.

Inform your doctor before combining Zithromax with:

carbamazepine (Tegretol); certain antihistamines such as Hismanal and Seldane; cydosporine (Sandimmune); digoxin (Lanoxin or Lanoxicaps); ergot-containing drugs such as Cafergot or D.H.E.; hexobarbital; lovastatin (Mevacor); phenytoin (Dilantin); theophylline drugs such as Bronkodyl, Slo-Phyllin, and Theo-Dur; triazolam (Halcion); warfarin (Coumadin).

No known food/other substance interactions.

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Not known if Zithromax appears in breast milk.

No special precautions apply to seniors.

Not generally prescribed for children under 16 years. Follow doctor’s instructions carefully for children 16 and older.

  • Possibility of rare, serious reactions, including an-gioedema (swelling of face, lips, and neck that impedes speaking, swallowing, and breathing) and anaphylaxis (violent, even fatal allergic reaction).
  • May cause pseudomembranous colitis, a potentially life-threatening form of diarrhea.
  • If a liver problem is present, should be monitored closely.


HealthSurvey.org provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Zithromax side effects, please contact your healthcare provider