Fosamin 3 Gm

Indications

Fosfomycin is an antibiotic. Taken by mouth as granules (fosfomycin trometamol), it is mainly used as a single dose treatment for uncomplicated urinary tract infections (cystitis) in women and adolescent girls caused by sensitive bacteria such as E. coli. It may also be used to prevent infection before some urinary procedures. An injectable form is used in hospital for serious infections.

How It Works

Fosfomycin stops bacteria from making the first building blocks of their cell wall. Without a proper wall the bacteria burst and die. After a single oral dose it reaches high levels in urine for 1 to 2 days, which is enough to clear most bladder infections.

Dosage and Administration

For uncomplicated cystitis in adult women, the usual dose is one 3 g sachet taken once. Dissolve the granules in half a glass of water and drink straight away. It is best taken on an empty stomach, 2 to 3 hours before or after a meal, preferably at bedtime after emptying the bladder. Do not take another dose unless your doctor tells you to. Injectable Fosfomycin is given only in hospital by a doctor or nurse.

Interactions

• Metoclopramide and other medicines that speed up the stomach may reduce its absorption.
• Taking it with food lowers absorption; take it on an empty stomach.

Contraindications

• Allergy to Fosfomycin.
• Severe kidney impairment (oral single dose).
• Kidney infection (pyelonephritis) or fever with back pain, which needs other treatment.

Side Effects

Common side effects include diarrhoea, nausea, indigestion, headache, dizziness and vaginal itching or discharge (thrush). These are usually mild and short lived. Rarely, a serious bowel infection (C. difficile associated diarrhoea) can occur even weeks after an antibiotic.

Get urgent medical help if you have signs of a serious allergic reaction (swelling of the face, lips or throat, difficulty breathing, widespread rash), severe or bloody diarrhoea, or if you develop fever, chills, back or side pain, or blood in the urine, as the infection may have spread to the kidneys.

Pregnancy and Lactation

A single dose may be used in pregnancy if a doctor decides it is the right choice. Small amounts pass into breast milk; a single dose is generally considered acceptable, but discuss with your doctor.

Precautions and Warnings

• Symptoms usually improve within 2 to 3 days; if they do not, see your doctor.
• Men, children and people with complicated or recurrent infections need medical assessment.
• Some sachets contain sugar; tell your doctor if you have diabetes.
• Drink plenty of fluids.

Overdose

Overdose may cause dizziness, changes in taste, nausea and diarrhoea. Drink plenty of fluids and seek medical advice.

Therapeutic Class

Antibiotic; phosphonic acid derivative.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.