Skip to Content

The originating document has been archived. We cannot confirm the completeness, accuracy and currency of the content.


Generic Name: erythromycin/sulfisoxazole (e-RITH-roe-MYE-sin/SUL-fi-SOX-a-zole)
Brand Name: E.S.P.

E.S.P. is used for:

Treating ear infections caused by certain bacteria. It may also be used for other conditions as determined by your doctor.

E.S.P. is a macrolide and sulfonamide antibiotic combination. It works by slowing the growth of and killing sensitive bacteria.

Do NOT use E.S.P. if:

  • you are allergic to any ingredient in E.S.P. or to any other sulfonamide medicine (eg, sulfamethoxazole)
  • you are pregnant and at term (38 to 42 weeks)
  • you are breast-feeding a child younger than 2 months old
  • the patient is a child younger than 2 months old
  • you have severe kidney problems, bladder blockage, or anemia caused by folic acid deficiency
  • you have a very slow heartbeat or a certain type of irregular heartbeat (QT prolongation, long QT syndrome)
  • you have low blood potassium or magnesium levels
  • you are taking certain antiarrhythmics (eg, amiodarone, dofetilide, dronedarone, procainamide, propafenone, quinidine, sotalol), asenapine, astemizole, cisapride, diltiazem, eletriptan, an ergot alkaloid (eg, dihydroergotamine, ergotamine), an HIV protease inhibitor (eg, ritonavir), certain imidazole antifungals (eg, itraconazole, ketoconazole, voriconazole), nilotinib, pimozide, a streptogramin (eg, quinupristin/dalfopristin), terfenadine, tetrabenazine, tolvaptan, or verapamil

Contact your doctor or health care provider right away if any of these apply to you.

Before using E.S.P.:

Some medical conditions may interact with E.S.P.. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have diarrhea or throat inflammation
  • if you have a history of asthma, blood problems, a glucose-6-phosphate dehydrogenase (G6PD) deficiency, kidney or liver problems, heart problems (eg, fast, slow, or irregular heartbeat), low blood potassium or magnesium levels, myasthenia gravis, or the blood disease porphyria
  • if you take any medicine that may increase the risk of a certain type of irregular heartbeat (prolonged QT interval). Check with your doctor or pharmacist if you are unsure if any of your medicines may increase the risk of this type of irregular heartbeat

Some MEDICINES MAY INTERACT with E.S.P.. Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Many prescription and nonprescription medicines (eg, used for aches and pains, allergies, blood thinning, breathing problems, cancer, diabetes, erection problems, gout, hepatitis C infection, high blood calcium levels, high blood pressure, high cholesterol, HIV infection, inflammation, infections, irregular heartbeat or other heart problems, low blood sodium levels, migraine, mood or mental problems, nausea and vomiting, overactive bladder, Parkinson disease, prevention of organ transplant rejection, seizures, stomach problems, trouble sleeping), multivitamin products, and herbal or dietary supplements (eg, herbal teas, coenzyme Q10, garlic, ginseng, ginkgo, St. John's wort) may also interact with E.S.P.. Ask your doctor or pharmacist if you are unsure if any of your medicines might interfere with E.S.P.

This may not be a complete list of all interactions that may occur. Ask your health care provider if E.S.P. may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use E.S.P.:

Use E.S.P. as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • Take E.S.P. by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation.
  • Drinking extra fluids while you are taking E.S.P. is recommended. Check with your doctor for instructions.
  • Do not eat grapefruit or drink grapefruit juice while you use E.S.P..
  • E.S.P. works best if it is taken at the same time(s) each day.
  • To clear up your infection completely, take E.S.P. for the full course of treatment. Keep taking it even if you feel better in a few days.
  • If you miss a dose of E.S.P., take it as soon as possible. If it is almost time for the next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use E.S.P..

Important safety information:

  • E.S.P. may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use E.S.P. with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Mild diarrhea is common with antibiotic use. However, a more serious form of diarrhea (pseudomembranous colitis) may rarely occur. This may develop while you use the antibiotic or within several months after you stop using it. Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
  • E.S.P. only works against bacteria; it does not treat viral infections (eg, the common cold).
  • Be sure to use E.S.P. for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
  • Long-term or repeated use of E.S.P. may cause a second infection. Tell your doctor if signs of a second infection occur. Your medicine may need to be changed to treat this.
  • Infrequently, a serious stomach problem called infantile hypertrophic pyloric stenosis (IHPS) has been reported in infants taking erythromycin. Contact your child's doctor right away if severe vomiting or irritability with feeding occurs.
  • Tell your doctor or dentist that you take E.S.P. before you receive any medical or dental care, emergency care, or surgery.
  • Rarely, patients taking E.S.P. have developed reversible hearing loss. This risk is greater if you have kidney problems or you take high doses of E.S.P.. Contact your doctor if you develop decreased hearing or hearing loss.
  • E.S.P. may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to E.S.P.. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.
  • E.S.P. may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking E.S.P..
  • Lab tests, including liver function, kidney function, complete blood counts, and urinalysis, may be performed while you use E.S.P.. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
  • E.S.P. should not be used in CHILDREN younger than 2 months old; safety and effectiveness in these children have not been confirmed.
  • Use E.S.P. with caution in the ELDERLY; they may be more sensitive to its effects, especially irregular heartbeat (prolonged QT interval).
  • PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using E.S.P. while you are pregnant. Do not take E.S.P. if you are pregnant and at term (38 to 42 weeks). E.S.P. is found in breast milk. Do not breast-feed while taking E.S.P..

Possible side effects of E.S.P.:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Dizziness; headache; loss of appetite; mild diarrhea; nausea; stomach pain; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); bloody or dark urine; bloody stools; change in the amount of urine produced; decreased hearing or hearing loss; fainting; fast or irregular heartbeat; fever, chills, or sore throat; mood or mental changes; numbness or tingling of the hands or feet; pale skin; red, swollen, blistered, or peeling skin; ringing in the ear; seizures; severe or persistent diarrhea, dizziness, or headache; severe stomach pain; shortness of breath; sore mouth or tongue; stomach cramps; symptoms of liver problems (eg, yellowing of skin or eyes; pale stools; severe or persistent nausea, vomiting, or loss of appetite; dark urine); unusual bruising or bleeding; unusual weakness or fatigue; vision changes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include blood in the urine; high fever; loss of consciousness; severe nausea, dizziness, drowsiness, headache, or vomiting; severe or persistent loss of appetite.

Proper storage of E.S.P.:

Store E.S.P. in the refrigerator, between 36 and 46 degrees F (2 and 8 degrees C). Do not freeze. Throw away any unused medicine after 14 days. Store away from heat, moisture, and light. Do not store in the bathroom. Keep tightly closed. Keep E.S.P. out of the reach of children and away from pets.

General information:

  • If you have any questions about E.S.P., please talk with your doctor, pharmacist, or other health care provider.
  • E.S.P. is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.
  • Check with your pharmacist about how to dispose of unused medicine.

This information should not be used to decide whether or not to take E.S.P. or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about E.S.P.. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to E.S.P.. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using E.S.P..

Issue Date: June 3, 2015