Azithromycin (Zithromax)

Azithromycin (Zithromax) is an antibiotic that belongs to the macrolide class of drugs. It is licensed for treating respiratory tract infections, infections of the middle ear, skin and soft tissue infections, and chlamydia. It is manufactured by Pfizer.

Azithromycin is an effective treatment for Mycobacterium avium intracellulare (MAI), cryptosporidiosis, bacillary angiomatosis and toxoplasmosis.1 2 3 Azithromycin is also effective in preventing MAI in people with advanced HIV infection who are unresponsive to anti-HIV therapy with a CD4 cell count below 100 cells/mm3 at a dose of 1200mg once a week.4 5 6

Some doctors also use azithromycin to treat syphilis with a single dose of 2000mg.7 However, an azithromycin-resistant strain of syphilis has recently been found in HIV-positive gay men in the United States and Ireland.8 A single case report has also shown that a 1000mg dose of azithromycin can cure early Lymphogranuloma venereum (LGV).9

Nausea is a frequent side effect of azithromycin at the dose of 600mg once a day used to treat MAI. Other side-effects include diarrhoea, abdominal pain and loose stools. The tablets contain lactose, to which some people are allergic. There is an increased risk of side-effects if it is taken at the same time as some anti-histamines and the anti-mycobacterial rifabutin (Mycobutin).

Azithromycin is best taken on an empty stomach to maximise absorption, and should be taken at least two hours apart from antacids or ddI (didanosine, Videx / VidexEC), which will interfere with absorption. There are no known interactions between azithromycin and any currently available protease inhibitors or non-nucleoside reverse transcriptase inhibitors (NNRTIs).


  1. Dunne MW et al. A randomized, double-blind trial comparing azithromycin and clarithromycin in the treatment of disseminated Mycobacterium avium infection in patients with human immunodeficiency virus. Clin Infect Dis 31: 1245-1252, 2000
  2. Araujo FG et al. Azithromycin, a macrolide antibiotic with potent activity against Toxoplasma gondii. Antimicrob Agents Chemother 32: 755-757, 1988
  3. Dionisio D et al. Chronic cryptosporidiosis in patients with AIDS: stable remission and possible eradication after long-term, low dose azithromycin. J Clin Pathol 51: 138-142, 1998
  4. Phillips P et al. Azithromycin prophylaxis for Mycobacterium avium complex during the era of highly active antiretroviral therapy: evaluation of a provincial program. Clin Infect Dis 34: 371-378, 2002
  5. Moyle GJ et al. Once weekly azithromycin as prophylaxis against recurrence of non-tuberculous mycobacterial infections in HIV-1-positive individuals. AIDS 12: 1555-1557, 1998
  6. Oldfield EC et al. Once weekly azithromycin therapy for prevention of Mycobacterium avium complex infection in patients with AIDS: a randomized, double-blind, placebo-controlled multicenter trial. Clin Infect Dis 26: 611-619, 1998
  7. Riedner G et al. Single-dose azithromycin versus penicillin G benzathine for the treatment of early syphilis. N Engl J Med 353: 1236-1244, 2005
  8. Lukehart SA et al. Macrolide resistance in Treponema pallidum in the United States and Ireland. N Engl J Med 351: 154-158, 2004
  9. Nieuwenhuis RF et al. Unusual presentation of early lymphogranuloma venereum in an HIV-1 infected patient: effective treatment with 1 g azithromycin. Sex Transm Infect 79: 453-455, 2003

Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.