PRECAUTIONS: Tell your doctor your medical history, including: allergies (especially to macrolide antibiotics such as erythromycin or clarithromycin), heart problems, kidney problems, kidney disease, liver disease. This medication contains sodium. Consult your doctor for more information if you are on a salt-restricted diet or if your condition could be worsened with an increase in salt intake (e.g., congestive heart failure). Use of this medication for prolonged or repeated periods may result in a secondary infection (e.g., mouth, bladder or vaginal yeast infection). Tell your doctor if you are pregnant before using this drug. It is not known whether this drug is excreted into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: digoxin, live vaccines, lovastatin, nelfinavir, warfarin. This medication may decrease the effectiveness of combination-type birth control pills. This can result in pregnancy. You may need to use an additional form of reliable birth control while using this medication. Consult your doctor or pharmacist for details. Other drugs besides azithromycin which may affect the heart rhythm (QTc prolongation in the EKG) include dofetilide, pimozide, procainamide, quinidine, sotalol, and sparfloxacin among others. QTc prolongation can infrequently result in serious, rarely fatal, irregular heartbeats. Consult your doctor or pharmacist for details. Ask for instructions about whether you need to stop any other QTc-prolonging drugs you may be using in order to minimize the risk of this effect. Do not start or stop any medicine without doctor or pharmacist approval.