How much Zithromax you take and how often you take it depends on many factors, including the condition being treated and the age and weight of the patient. If you have any questions about the amount and/or frequency of Zithromax you are taking, talk with your health care provider. Carefully read the patient leaflet provided with Zithromax and reread it each time you get this prescription refilled. Take Zithromax exactly -as prescribed by your health care provider. Zithromax may be taken with or without food. Do not take antacids that contain magnesium or aluminum at the same time that you are taking Zithromax. Long-term or repeated use of Zithromax may cause a second infection. You may need to stop taking Zithromax and start another medication to treat the second infection. Contact your doctor if signs of a second infection occur. Take all of the prescribed medicine. Failure to take all of the Zithromax may prevent complete elimination of bacteria, allowing the infection to return. If severe diarrhea, stomach cramps/pain, or bloody stools occur, contact your health care provider at once. This could be a sign of a serious side effect requiring immediate medical attention. Do not treat diarrhea without talking to your doctor. Zithromax may cause dizziness or drowsiness. Use caution while driving or performing other tasks requiring alertness, coordination, or physical dexterity. Zithromax may cause sensitivity to sunlight. Avoid prolonged exposure to the sun and other ultraviolet light. Use sunscreens and wear protective clothing until tolerance is determined. Do not stop taking Zithromax without checking with your doctor. Patients with previous medical conditions should talk with their health care provider before using Zithromax. Do not take any othe over-the-counter or prescription medications without talking with your doctor. This includes any herbal preparations or dietary supplements. Do not take more Zithromax than prescribed unless advised to do so by your doctor or health care provider.