How effective is Azithromycin(Zithromax)in treating Chlamydia? Taken only once is really 100 effective as a cure for Chlamydia?
Azithromycin works very well for Chlamydia. As with all infections, there is always a chance that the drug may not work. Reasons may include that the person does not metabolize or absorb the drug, sometimes an organism is resistant to the drug or factors we may not completely understand. I do not know of any reports of azithromycin resistant Chlamydia. In the controlled trial comparing single dose azithromycin with 7 days of doxycycline, the cure rate for azithromycin was 95 % in men and 97% in women. So, it is pretty effective but not 100%.
The most common reason I see for not getting "cured" is due to re-infection. It is critical that your partner(s) be treated as well otherwise you will just get the infection back. Remember to use condoms all the time. Chlamydia is one of the most common sexually transmitted diseases and can result in serious infections leading to infertility.