Reviewed on 5/8/2023

Generic Name: Fosfomycin

Brand Name:  Monurol

Drug Class: Antibiotics, Other

What Is Fosfomycin and How Does It Work?

Fosfomycin is a prescription medication used to treat the symptoms of bacterial infections such as urinary tract infection

  • Fosfomycin is available under the following different brand names: Monurol.

What Are Dosages of Fosfomycin?

Adult dosage

Powder for reconstitution

  • 3g/packet 

Urinary Tract Infection (Acute Cystitis)

Adult Dosages

  • Acute cystitis caused by E. coli, E. faecalis
  • Acute uncomplicated cystitis: 3g orally once
  • Multi-drug resistant UTI: 2-3 g orally every 2-3 days for 3 doses

Pediatric Dosage

  • Safety and efficacy not established. 

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."

What Are Side Effects Associated with Using Fosfomycin?

Common side effects of Fosfomycin include:

Serious side effects of Fosfomycin include:

  • hives, 
  • difficulty breathing, 
  • swelling of the face, lips, tongue, or throat, 
  • clay-colored stools, 
  • diarrhea that is watery or bloody, 
  • burning or painful urination, and
  • new or worsening bladder symptoms 

Rare side effects of Fosfomycin include:

  • none 

This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Fosfomycin?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first

This information does not contain all possible interactions or adverse effects.  Visit the RxList Drug Interaction Checker for any drugs interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use.  Keep a list of all your medications with you, and share this information with your doctor and pharmacist.  Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.


What Are Warnings and Precautions for Fosfomycin?


  • Hypersensitivity 

Effects of drug abuse

  • None

Short-Term Effects

  • See “What are Side Effects Associated with Using Fosfomycin?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Fosfomycin?”


  • Hepatic injury, including hepatitis and steatosis reported; monitor liver function; effect is reversible upon discontinuation of drug
  • Prolonged use may result in bacterial or fungal superinfections, which may appear up to two months post-antibiotic treatment
  • Hypersensitivity reactions, including anaphylactic shock reported; discontinue use at first signs of hypersensitivity reactions and institute supportive measures

Pregnancy and Lactation

  • Use may be acceptable during pregnancy.  
  • Excreted in breast milk; not recommended.

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