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Fosfomycin Tromethamine

Generic name: fosfomycin [ FOS-foe-MYE-sin ]
Brand name: Fosfomycin Tromethamine
Drug classes: Miscellaneous antibiotics, Urinary anti-infectives

Medically reviewed by on Dec 21, 2023. Written by Cerner Multum.

What is Fosfomycin Tromethamine?

Fosfomycin Tromethamine is an antibiotic that fights infection caused by bacteria.

Fosfomycin Tromethamine is used to treat bladder infections.

Fosfomycin Tromethamine may also be used for purposes not listed in this medication guide.

Fosfomycin Tromethamine side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Fosfomycin Tromethamine may cause serious side effects. Call your doctor at once if you have:

Common side effects of Fosfomycin Tromethamine may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Use only as directed. Tell your doctor if you use other medicines or have other medical conditions or allergies.

Before taking this medicine

You should not use Fosfomycin Tromethamine if you are allergic to it.

Tell your doctor if you are pregnant or breastfeeding.

Fosfomycin Tromethamine should not be given to a child younger than 12 years old.

Do not share Fosfomycin Tromethamine Tromethamine with another person, even if they have the same symptoms you have.

How should I take Fosfomycin Tromethamine?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Fosfomycin Tromethamine is usually given in only one dose. Do not take more than a single dose unless your doctor tells you to.

You may take Fosfomycin Tromethamine with or without food.

Fosfomycin Tromethamine is a powder medicine that must be mixed with water before using it. Do not take the dry powder without adding water.

Dissolve the powder in 3 to 4 ounces (1/2 cup) of cold water. Stir this mixture and drink all of it right away. To make sure you get the entire dose, add a little more water to the same glass, swirl gently and drink right away.

Do not mix Fosfomycin Tromethamine oral powder with hot water.

It may take 2 or 3 days before your symptoms improve.

Call your doctor if your symptoms do not improve within 3 days after treatment, or if you have any other new symptoms.

To be sure Fosfomycin Tromethamine is the right antibiotic for the type of infection you have, your urine may need to be tested before and after you take this medicine.

Store at room temperature away from moisture and heat. Keep the powder in its original package until you are ready to mix your dose.

What happens if I miss a dose?

Fosfomycin Tromethamine Tromethamine is used as a single dose and does not have a daily dosing schedule.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include hearing problems and altered sense of taste.

What should I avoid while taking Fosfomycin Tromethamine?

Antibiotic medicines can cause diarrhea. Tell your doctor if you have diarrhea that is watery or bloody.

What other drugs will affect Fosfomycin Tromethamine?

Tell your doctor about all your other medicines, especially metoclopramide.

Other drugs may affect Fosfomycin Tromethamine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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