Skip to main content


Generic name: Fosfomycin [ fos-foe-MYE-sin ]
Brand name: Monurol
Drug classes: Miscellaneous antibiotics, Urinary anti-infectives


  • This medicine has sodium in it. Your hydration and electrolytes will need to be watched closely while you take fosfomycin. You may need to follow a low-sodium diet while taking fosfomycin. Tell your doctor if you have any of these health problems: heart problems, high blood pressure, hyperaldosteronism, kidney or liver problems, high sodium levels, or fluid in the lungs. If you have questions, talk with your doctor.

Uses of Fosfomycin:

Powder packet:

  • It is used to treat a urinary tract infection (UTI).


  • It is used to treat bacterial infections.

What do I need to tell my doctor BEFORE I take Fosfomycin?

  • If you are allergic to fosfomycin; any part of fosfomycin; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take fosfomycin with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Fosfomycin?

All products:

  • Tell all of your health care providers that you take fosfomycin. This includes your doctors, nurses, pharmacists, and dentists.
  • Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.


  • Have blood work checked as you have been told by the doctor. Talk with the doctor.
  • Allergic reactions have happened with fosfomycin. Rarely, some reactions can be very bad or life-threatening. Talk with the doctor.

How is this medicine (Fosfomycin) best taken?

Use fosfomycin as ordered by your doctor. Read all information given to you. Follow all instructions closely.

Powder packet:

  • Take with or without food as you have been told by your doctor.
  • Do not take dry powder.
  • Mix with 1/2 cup of cold water and drink it right away.
  • Do not use hot water to mix fosfomycin.


  • It is given as an infusion into a vein over a period of time.

What do I do if I miss a dose?

Powder packet:

  • Only 1 dose of fosfomycin is needed. If you miss your dose, take it as soon as you think about it.


  • Call your doctor to find out what to do.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

All products:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Diarrhea is common with antibiotics. Rarely, a severe form called C diff–associated diarrhea (CDAD) may happen. Sometimes, this has led to a deadly bowel problem (colitis). CDAD may happen during or a few months after taking antibiotics. Call your doctor right away if you have stomach pain, cramps, or very loose, watery, or bloody stools. Check with your doctor before treating diarrhea.


  • Signs of electrolyte problems like mood changes, confusion, muscle pain or weakness, a heartbeat that does not feel normal, seizures, not hungry, or very bad upset stomach or throwing up.
  • Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
  • Sweating a lot.
  • Very upset stomach or throwing up.
  • Change in color of skin to a bluish color like on the lips, nail beds, fingers, or toes.

What are some other side effects of Fosfomycin?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

Powder packet:

  • Headache.
  • Vaginal itching or discharge.
  • Diarrhea.
  • Upset stomach.


  • Stomach pain.
  • Throwing up.
  • Irritation where the shot is given.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Fosfomycin?

Powder packet:

  • Store at room temperature in a dry place. Do not store in a bathroom.


  • If you need to store fosfomycin at home, talk with your doctor, nurse, or pharmacist about how to store it.

All products:

  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Consumer Information Use and Disclaimer

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about fosfomycin, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.