Azithromycin treatment for pneumonia is effective in some people and not significantly in others. Azithromycin belongs to the macrolide class of drugs and is effective against mycoplasma, chlamydia, and gram-positive bacteria. If the lung inflammation is caused by mycoplasma and chlamydia infection, azithromycin is very effective in treating it. If it is caused by other bacteria, the rate of drug resistance is higher and none of them are very effective. So when treating pneumonia, if it is considered to be caused by mycoplasma and chlamydia you can consider using azithromycin. If it is considered to be caused by other bacteria not as the first choice of drugs, consider the use of other antibiotics for treatment.