Fosfomycin — Uses, Dosage, Side Effects & Safety

Drug class: Antibiotic (Phosphonic acid derivative)

Overview

Fosfomycin is an antibiotic used to treat uncomplicated urinary tract infections (UTIs) caused by certain bacteria. It is especially useful for treating infections caused by bacteria that are resistant to other antibiotics. Fosfomycin works by stopping the growth of bacteria, helping your body fight off the infection. This medication is typically given as a single-dose oral treatment for women with uncomplicated UTIs, but it may also be used intravenously in hospitals for more serious infections. It is important to take fosfomycin exactly as prescribed and to complete the full course, even if you start to feel better. Key points: Fosfomycin is not effective against viral infections (such as colds or flu). Only use it for bacterial infections as directed by your healthcare provider. Let your doctor know if you have kidney problems or are pregnant before starting this medication.

Therapeutic uses

  • Uncomplicated urinary tract infections (UTIs) in women
  • Prophylaxis for transrectal prostate biopsy
  • Complicated urinary tract infections (off-label)
  • Bacterial cystitis

Common side effects

  • Diarrhea
  • Nausea
  • Headache
  • Vaginitis
  • Abdominal pain
  • Rash
  • Dizziness

Frequently Asked Questions about Fosfomycin

What is fosfomycin used for?

Fosfomycin is primarily used to treat uncomplicated urinary tract infections (UTIs) in women caused by susceptible bacteria. It may also be used in hospitals for more serious infections, such as complicated UTIs or infections caused by multidrug-resistant organisms.

How should I take fosfomycin oral granules?

Dissolve the contents of the packet in a glass of water (not hot), stir well, and drink immediately. Take on an empty stomach, at least 2–3 hours before or after a meal.

Can I take fosfomycin if I am pregnant or breastfeeding?

Fosfomycin should only be used during pregnancy or breastfeeding if clearly needed and prescribed by your doctor. Discuss the risks and benefits with your healthcare provider.

What should I do if I experience severe diarrhea while taking fosfomycin?

Contact your doctor immediately. Severe or persistent diarrhea may be a sign of a serious intestinal condition (Clostridioides difficile-associated diarrhea) and requires prompt medical attention.

Are there any foods or medicines I should avoid while taking fosfomycin?

Avoid taking fosfomycin with food, as it may reduce absorption. Also, avoid taking metoclopramide or mineral supplements close to the time of your dose.

Can fosfomycin be used in children?

Fosfomycin is not routinely recommended for uncomplicated UTIs in children. For other infections, dosing is determined by a healthcare provider based on weight and clinical need.

What are the signs of an allergic reaction to fosfomycin?

Signs include rash, itching, swelling (especially of the face/tongue/throat), severe dizziness, and difficulty breathing. Seek emergency medical help if these occur.

Educational information only. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.