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.
Call your doctor at once if you have:
diarrhea that is watery or bloody; or
new or worsening bladder symptoms (burning, painful urination).
Common side effects may include:
nausea, upset stomach, mild diarrhea;
headache, dizziness;
weakness;
sore throat, runny nose;
back pain; or
vaginal itching or discharge.
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.
 Fosfomycin side effects (more detail)
