Fosfomycin (By injection)

Fosfomycin (fos-foe-MYE-sin)

Treats complicated urinary tract infections (cUTI).

Brand Name(s):

Contepo

When This Medicine Should Not Be Used:

How to Use This Medicine:

Injectable

• Your doctor will prescribe your dose and schedule. This medicine is given through a needle placed in a vein. This medicine must be given slowly, so the IV will have to stay in place for at least 1 hour.
• A nurse or other health provider will give you this medicine.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how fosfomycin works. Tell your doctor if you are using medicine for heart rhythm problems, medicine to treat depression (including TCAs), medicine to treat mental problems, or other medicine to treat an infection (including macrolides).

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant, or if you have kidney disease, liver disease, electrolyte problems, heart problems, heart rhythm problems, high blood pressure, or lung or breathing problems.
• Do not breastfeed during treatment and for 24 hours after the last dose.
• This medicine may cause the following problems:
  • Electrolyte problems, including hypokalemia (low potassium in the blood) and hypocalcemia (low calcium levels in the blood)
  • Heart rhythm problems, including QT prolongation and torsade de pointes
• This medicine may make you bleed, bruise, or get infections more easily. Take precautions to prevent illness and injury. Wash your hands often.
• This medicine can cause diarrhea. Call your doctor if the diarrhea becomes severe, does not stop, or is bloody. Do not take any medicine to stop diarrhea until you have talked to your doctor. Diarrhea can occur 2 months or more after you stop taking this medicine.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Confusion, mood or mental changes, seizures, trouble breathing
• Dry mouth, increased thirst, muscle cramps, nausea or vomiting
• Fainting, dizziness, lightheadedness
• Fast, pounding, or uneven heartbeat
• Fever, chills, cough, sore throat, body aches
• Headache
• Muscle twitching, weakness
• Rapid weight gain, swelling in your hands, ankles, or feet
• Stomach cramps, pain, or tenderness, watery or bloody diarrhea

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 12/4/2025