Fosfomycin 3Gm Sachet an antibiotic used to treat urinary tract infections (UTIs), can cause side effects such as diarrhea, nausea, vomiting, and abdominal pain. Less common side effects may include headaches, dizziness, skin rash, and allergic reactions like itching or swelling. Serious side effects like liver problems or severe allergic reactions are rare but possible. It's important to inform a healthcare provider of any unusual symptoms while taking fosfomycin for appropriate monitoring and management. Follow the prescribed dosage and duration of treatment to minimize the risk of side effects and ensure effective UTI treatment.