It is very important that your doctor check the progress of you or your child at regular visits to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects. If your or your child's symptoms do not improve within a few days, or if they become worse, check with your doctor.
Do not use this medicine if you or your child are also using astemizole (Hismanal®), cisapride (Propulsid®), pimozide (Orap®), or terfenadine (Seldane®). Using these medicines together may increase risk for more serious side effects.
Check with your doctor right away if you or your child have pain or tenderness in the upper stomach; pale stools; dark urine; loss of appetite; nausea; unusual tiredness or weakness; or yellow eyes or skin. These could be symptoms of a serious liver problem.
This medicine can cause changes in heart rhythms, such as a condition called QT prolongation. It may change the way your heart beats and cause fainting or serious side effects in some patients. Contact your doctor right away if you or your child have worsening symptoms of heart rhythm problems, such as fast, pounding, or uneven heartbeats.
Make sure your doctor knows if you are pregnant or may be pregnant before taking this medicine.
Erythromycin may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop using this medicine. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you have any questions about this or if mild diarrhea continues or gets worse, check with your doctor.
Before you have any medical tests, tell the medical doctor in charge that you or your child are using this medicine. The results of some tests may be affected by this medicine.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.