Fosfomycin (Oral)


What is Fosfomycin?

Fosfomycin is an antibiotic drug that is effective against many types of bacteria. Not only is Fosfomycin effective against gram-positive bacteria, like staphylococci, it is also used in the treatment of gram-negative bacteria as well.

Discovered in 1969, Fosfomycin has been in use world-wide for a variety of purposes, but it is considered a targeted antibiotic with regard to infections of the bladder or the urinary tract. Fosfomycin is also sold under the trade names of Monurol and Monuril.

How does Fosfomycin work?

Fosfomycin goes to work in the body by deactivating an enzyme known as MurA, which helps bacteria cells divide and grow. It does this through chemical intervention by becoming an alkaline type of substance, which does not allow bacteria to thrive.

It is especially effective against Escherichia coli and Enterococcus faecalis, two bacteria strains that commonly cause an infection in the urinary tract or bladder in female patients. Fosfomycin concentrates itself in the kidneys and in the bladder, which enables it to be most effective to infections found in those areas.

What is an infection of the bladder or urinary tract?

The urinary tract ranges from the kidneys down to the bladder and urethra. An infection in this area is known as a UTI or, if concentrated in the bladder, a bladder infection or cystitis. Kidney infection is known as pyelonephritis.

Symptoms include painful or frequent urination, sometimes both, and a sensation that you have to urinate when your bladder is actually empty. Occasionally, patients may see blood when they urinate and some experience elevated body temperature and other body pain.

Typically caused by a bacteria named Escherichia coli that is introduced to the urinary tract during sexual intercourse or other means, the bacteria that causes this infection is targeted by the active ingredients found in Fosfomycin.

Type Of Medicine

  • Antibiotic, broad spectrum

Conditions Treated

  • Uncomplicated enterococcal infection of the urinary tract
  • Complicated infection of the urinary tract
  • Uncomplicated escherichia infection of the urinary tract

Side Effects

Fosfomycin attacks bacteria found in the body, with specially concentrated use in the kidneys and bladder due to the mechanism of its formulation. While doing so, it may also cause adverse effects on the health of some patients. If you experience symptoms including the following, contact your doctor immediately:

  • Signs of blood in urine
  • Burning sensation during urination
  • Urinating is painful or difficult
  • Chills
  • Fever
  • Pain in side or lower back
  • Tender, painful abdomen or stomach
  • Stools show signs of blood or are black in color and tar like
  • Bloated abdomen
  • Pain in chest
  • Stools are color of clay or are light in color
  • Constipated
  • Urine is dark
  • Diarrhea
  • Swallowing is difficult
  • Dizzy
  • Rapid heart rhythm
  • Headache
  • Itchy skin with or without hives
  • Swollen patches on eyes, face, sex organs, tongue, lips, hands, throat, legs or feet
  • Little to no appetite
  • Vomiting
  • Nauseated feeling
  • Swollen, puffy eyes or face, tongue or lips
  • Skin rash
  • Cramps or pain in stomach or abdomen
  • Difficulty breathing
  • White, ulcerated sores in the mouth or on lips
  • Painful, swollen glands
  • Chest feels tight
  • Halitosis
  • Bruising or bleeding that is unexpected or unusual
  • Fatigue
  • Weak muscles
  • Vomit with signs of blood
  • Diarrhea that is severe, watery or bloody
  • Wheezing
  • Increase of asthma symptoms
  • Skin or eyes appear yellow

Other health effects are not an emergency, but still should be brought to the attention of your physician. If these symptoms do not go away as you get used to the medication, let your physician know that you have:

  • Itching genital or vaginal area
  • Painful sex
  • White discharge, with or without odor, from vagina
  • Acid reflux
  • Pain in back
  • Gas
  • Pain or aches
  • Congested nasal passages, sneezing, stuffed or running nose
  • Throat soreness or dryness
  • Bleeding that is excessive
  • Heartburn, indigestion
  • Weakness
  • Menstruation pain
  • Rash on skin
  • Throat soreness
  • Upset stomach
  • Neck glands are swollen or tender
  • Difficulty swallowing
  • Changes in voice
  • Stools are abnormal in color
  • Skipping a menstrual period or irregularity
  • Loss of vision
  • Color blindness with yellow or blue
  • Vision changes or diminishes
  • Tingling, crawling, burning, itchy, numb feeling
  • Moving is difficult
  • Mouth is dry
  • Pain in eyes
  • Stomach feels full
  • Throbbing headache that is severe in nature
  • Pain in joints
  • Little to no appetite
  • Cramped, achy muscles
  • Stiff, painful muscles
  • Nervous demeanor
  • Fatigue
  • Insomnia
  • Halt of menstrual periods
  • Joints are swollen
  • Lymph glands in armpit or neck are painful, tender or swollen
  • Loss of weight
  • Loss of hearing

You may also have other health changes than those that are listed here. If you experience any symptoms after taking Fosfomycin, report these to your doctor who may be able to assist you with ways to avoid or eliminate these effects.


Fosfomycin should be taken exactly as your prescription is written by your physician, without taking higher amounts, taking more frequent doses or prolonging the dosage period. If you alter your prescribed amount, you may diminish the effectiveness or cause adverse health effects.

Fosfomycin works in one dose to fight a bladder or urinary tract infection, continuing long after you take it to fight the bacteria in your system. Mix the flavored powder with three to four ounces of water only and do not take it dry. Stir until the powder dissolves and consume the drink immediately. You are encouraged to consume extra fluids at this time, preferably those that are clear, in order to flush your system and prevent problems in your bladder.

Adult patients will typically receive a prescription of three grams which is contained in one package of the medication for dissolving in water for a single dose. Pediatric patients and teenagers will have their dosage determined by their physician based on their health condition and body mass.

You may take Fosfomycin with or without food, as indicated by your doctor's instructions found with your prescription information.


Fosfomycin oral medication has certain risk factors that your health care provider will go over with you in detail. You will also be given a patient leaflet that you should read completely and ask questions about if you don't understand the information clearly.

Hypersensitivity to other medications, certain foods, animals, artificial additives and dyes should be communicated to your health care provider to avoid any unwanted reactions to Fosfomycin. Bring a list of your current medications with you on your next doctor visit and include any non-prescription, herbal, holistic or vitamin supplements that you're taking.

Some medications are able to be used together without harm or reduced effectiveness of either drug. Combination therapies are a way to combat symptoms and make the patient more able to live a normal life. However, there are some drugs that should not be combined. The following drug should never be used with Fosfomycin:

Consult with your physician on whether to take Fosfomycin with food or whether certain foods should be eliminated from your diet altogether. You should also inform your doctor if you are a regular user of tobacco products or alcoholic beverages, as these could affect the way Fosfomycin works for you.

Your full medical history should be communicated to your physician in case you have diseases that would be dangerously affected by use of a statin drug, such as Fosfomycin. Specifically, the following health conditions have been known to become worse or limit the effectiveness of this medication:

  • Kidney diseases
  • Diarrhea


Be sure to maintain your scheduled visits to your doctor's office while on this medication so that the effectiveness and safety of Fosfomycin can be confirmed. Follow all instructions given to you by your doctor exactly and contact them if you have any questions or if anything is unclear. Report any worsening of your symptoms to your health care provider, along with any conditions that do not improve within three days of taking Fosfomycin.

Fosfomycin should not be used in children, as there have not been any studies to determine if it is safe.

Geriatric patients should be prescribed Fosfomycin with the caution that, due to age-related liver and kidney functions that may be slower than other adults; as such, their dosage may need to be adjusted. Similar caution should be taken with geriatric patients who have coronary diseases.

This medication does travel through the blood stream and should be avoided by women who are pregnant as it could be harmful to their unborn children. Breastfeeding women should also avoid Fosfomycin for this reason. Check with your physician for further advice on the use of this medication if you are pregnant or breastfeeding.

Unless you have cleared it with your doctor, do not take other medications while you are taking Fosfomycin. Other drugs, even those sold over the counter, could heighten health risks or diminish the effectiveness of this medication.

Fosfomycin may give some patients diarrhea that, in some cases, could be severe. This condition can happen up to 60 days post treatment, so notify your physician if you have diarrhea during this time before you take any medications to treat it yourself.

Avoid drugs that speed up the digestive tract while you are taking Fosfomycin. Do not take this medication if you are suffering from diarrhea, as it will worsen this condition and possibly cause health effects that are severe in nature.

Patients with slow function of their kidneys or diseases of the kidneys should avoid treatment with Fosfomycin, as the medication could remain in their systems too long and cause adverse health effects.


If you aren't taking Fosfomycin immediately, retain the original packaging that your prescription comes in and use it to store this medication properly. Keep this medicine at room temperature, away from exposure to excessive light, heat or moisture. Do not allow Fosfomycin to freeze and do not use it if it has become frozen. This medication, as well as others, should be kept out of sight and reach of children and pets.

Expired or unused Fosfomycin dosages should be disposed of properly according to your physician's instructions for safety. If this is not provided to you by your physician, consult with your pharmacist on safe disposal practices.


Fosfomycin is an anti-bacterial powdered medication that is mixed with clear water and taken as a drink. This medication is effective with one dose in fighting urinary tract or bladder infections in female patients. These infections are caused by the Escherichia coli bacteria and are not viral in nature. In uncomplicated cases, treatment with Fosfomycin is typically an effective treatment with improvements to the infection within three days after taking it.

Complications, including diarrhea, are known to happen with a dose of Fosfomycin. If this becomes severe or shows signs of blood, report it to your physician before using any medications to treat it yourself. Get word to your physician if your condition hasn't improved or has become worse after taking Fosfomycin, which should work immediately on your infection to clear up your symptoms.

Pediatric patients and those who are pregnant or nursing infants should not be prescribed Fosfomycin unless their health requirements exceed the increased risk of this group. Geriatric patients who have liver, kidney or heart problems should use caution before taking Fosfomycin. Use caution when considering treatment with Fosfomycin and discuss any risks with your physician.

Do not take other medicines, including those that can be purchased without a prescription, unless your doctor has specifically approved them for your use. This includes any vitamins and any holistic or herbal supplements. Patients being treated with medications to adjust the speed of their digestive tract should avoid treatment with Fosfomycin, as it could cause adverse affects on their health.