CONTRAINDICATIONS

Serious allergic reactions, including angioedema, anaphylaxis, and dermatologic reactions
including Stevens Johnson Syndrome and toxic epidermal necrolysis have been reported rarely in patients on azithromycin therapy. Although rare, fatalities have been reported. Despite initially successful symptomatic treatment of the allergic symptoms, when symptomatic therapy was discontinued, the allergic symptoms recurred soon thereafter in some patients without further azithromycin exposure. These patients required prolonged periods of observation and symptomatic treatment. The relationship of these episodes to the long tissue half-life of azithromycin and subsequent prolonged exposure to antigen is unknown at present.
If an allergic reaction occurs, the drug should be discontinued and appropriate therapy should be nstituted. Physicians should be aware that reappearance of the allergic symptoms may occur when symptomatic therapy is discontinued. In the treatment of pneumonia, azithromycin has only been shown to be safe and  effective in the treatment of community-acquired pneumonia due to Chlamydia pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae or Streptococcus pneumoniae in patients
appropriate for oral therapy. Azithromycin should not be used in patients with pneumonia who are judged to be inappropriate for oral therapy because of moderate to severe illness or risk factors such as any of the following: patients with cystic fibrosis, patients with nosocomially acquired infections, patients with known or suspected bacteremia, patients requiring hospitalization, elderly or debilitated patients, or patients with significant
underlying health problems that may compromise their ability to respond to their illness (including immunodeficiency or functional asplenia).
Pseudomembranous colitis has been reported with nearly all antibacterial agents and may
range in severity from mild to life-threatening. Therefore, it is important to consider this
diagnosis in patients who present with diarrhea subsequent to the administration of
antibacterial agents.
Treatment with antibacterial agents alters the normal flora of the colon and may permit
overgrowth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is a
primary cause of “antibiotic-associated colitis.”
After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to discontinuation of the drug alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an antibacterial drug clinically effective against Clostridium difficile colitis.