Antibiotics for chlamydia


Generic Name Brand Name
amoxicillin Amoxil, Trimox
azithromycin Zithromax
doxycycline Doryx, Vibramycin, Vibra-Tabs
erythromycin E-Base, Erythrocin
erythromycin ethylsuccinate E.E.S. 400, EryPed
levofloxacin Levaquin
ofloxacin Floxin

How It Works

Antibiotics kill the chlamydia bacteria.

Why It Is Used

Antibiotics are given to:

  • People who have positive chlamydia tests.
  • Sex partners within the last 60 days of people diagnosed with chlamydia—even if they do not have symptoms.
  • Newborns of women who have chlamydia at the time of delivery.

All of these medicines are prescribed for men and for women who are not pregnant. Pregnant women can take only erythromycin, amoxicillin, and azithromycin. Only erythromycin is given to babies.

How Well It Works

Antibiotic treatment, if taken exactly as directed, normally cures chlamydia infections. If antibiotics are not taken properly, the infection will not be cured.

The number of days you take antibiotics depends on your illness and the type of antibiotic medicine. Azithromycin and doxycycline cure chlamydia in up to 95 out of 100 cases. Some people may not be able to take these medicines but are able to take a different one.1

Side Effects

The most common side effects of these medicines are nausea and vomiting. Taking azithromycin after eating may reduce nausea.

Doxycycline causes less nausea and vomiting but may cause yeast infections in women.

Erythromycin treatments may cause more side effects (such as nausea) than other treatments.1

If side effects occur and cannot be controlled, tell your doctor. Other antibiotics may be prescribed that cause fewer side effects.

A large study indicates that people who take erythromycin along with certain common medicines may increase their risk of sudden cardiac death.2 The study showed that the risk of sudden cardiac death is greater when erythromycin is taken with some medicines that inhibit certain liver enzymes—such as certain calcium channel blockers, certain antifungal medicines, and some antidepressants—than when these medicines are not taken together.

Levofloxacin and ofloxacin increase the risk of a tendon rupture or other tendon damage. If you have sudden pain or swelling around your ankle, shoulder, elbow, or hand while taking one of these medicines, tell your doctor. Do not exercise until your doctor says it is okay.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

To be effective, antibiotics need to be taken as directed. If doses are missed or treatment is not completed, the chlamydia infection may not be cured.

The advantage of azithromycin is that it is taken in one dose. Because it is easy to take as prescribed, this medicine may help reduce the risk of spreading chlamydia.

Do not have sex while you are being treated for an STD. People taking a single dose of azithromycin should not have sex for 7 days after treatment.

Call your doctor if symptoms continue or if new symptoms develop 3 to 4 weeks after treatment.

Repeated chlamydia infections increase the risk of pelvic inflammatory disease (PID). Some doctors may recommend retesting 3 to 12 months after treatment to reduce the risk of complications from reinfection.3

For pregnant women, testing is recommended 3 weeks after treatment. This is done to prevent complications from an infection that has not been cured.3

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  1. Horner P (2008). Chlamydia (uncomplicated, genital), search date January 2007. Online version of BMJ Clinical Evidence:
  2. Ray WA, et al. (2004). Oral erythromycin and the risk of sudden death from cardiac causes. New England Journal of Medicine, 351(11): 1089–1096.
  3. Centers for Disease Control and Prevention (2006). Sexually transmitted diseases treatment guidelines 2006. MMWR, 55(RR-11): 38–42.

Last Updated: January 9, 2009

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