Fosfomycin

Fosfomycin is an antibiotic medication that is used to treat urinary tract infections (UTIs) and cystitis (a bladder infection). It can be used in women who are otherwise healthy and not pregnant. Fosfomycin is a generic version of the branded medication Monuril.

Fosfomycin works by killing bacteria, such as Escherichia coli. It does this by interfering with the bacterial cell wall, so that they are unable to survive and grow. It also prevents the bacteria from growing again and the infection from returning.

UTIs and cystitis are usually caused by bacteria from the bowels or skin entering the urethra and causing pain when you pee. You can also get cystitis from irritation or rubbing during sex or having a catheter fitted.

How long does fosfomycin take to work?

You should start to see improvements in your symptoms after 2 to 3 days of taking fosfomycin.

How effective is fosfomycin?

Fosfomycin is an effective treatment for UTIs, with 68.8% of participants with multidrug-resistant UTIs seeing improvements.

Fosfomycin works best when:

• taken on an empty stomach, or at least 2 to 3 hours after eating
• your bladder is empty

A fosfomycin sachet is usually taken as a single 3g dose treatment. You should follow your doctor’s instructions and only take additional doses if they tell you to. To take fosfomycin, you should:

1. Choose a suitable time to take fosfomycin. It’s most effective to take it when your bladder is empty and on an empty stomach, so a good time may be just before going to bed.
2. Pour the whole sachet of powder into a glass of 50 to 75ml of water that’s either cold or room temperature.
3. Stir until the powder dissolves.
4. Swallow this straight away.

Do not consume the powder on its own. You can take fosfomycin with food if you need to.

Fosfomycin can cause some side effects which should go away on their own. Not everyone will experience side effects.

Common side effects of fosfomycin include:

• headaches
• dizziness
• indigestion
• feeling sick (nausea)
• diarrhoea
• pain in the abdomen

Less common side effects include:

• being sick
• a rash
• itching
• tiredness

In rare cases, fosfomycin can lead to:

• allergic reaction
• vision issues
• dry mouth

Fosfomycin can sometimes cause serious side effects. You should speak with your doctor right away or call 999 in an emergency if you experience:

• an allergic reaction, causing swelling of the mouth, throat, and tongue, shortness of breath, and difficulty breathing (this is a medical emergency and you should call 999)
• fever or chills
• rapid heartbeat
• blood in your pee or poo
• lower back or side pain

How long do fosfomycin side effects last

Usually, side effects from fosfomycin should only last a few days. If they do not improve or start to worsen after 2 to 3 days, you should speak with your doctor.

What to do if you get fosfomycin side effects

Most side effects will be mild and should clear up quickly. You can treat:

• headaches and dizziness by staying well hydrated, getting enough rest, and taking over-the-counter medications like ibuprofen or paracetamol
• feeling sick (nausea), indigestion and diarrhoea by eating small, bland meals, staying hydrated, and getting fresh air

If you experience side effects that are severe or get worse, speak with your doctor.

Fosfomycin may not be suitable for everyone. If you have a medical condition or take certain medications, fosfomycin may be less effective or potentially unsafe. You should speak to your doctor before taking fosfomycin if you are pregnant or have an intolerance to any sugars.

Fosfomycin should not be taken if you:

• are allergic to any of its ingredients
• have ever had diarrhoea after taking antibiotics

Fosfomycin and other medical conditions

You should speak to your doctor before taking fosfomycin if you:

• have persistent infections of the bladder
• have kidney problems
• are undergoing a process to clean and filter your blood (hemodialysis)

Fosfomycin and other medications

Certain medications can interact with fosfomycin and may affect how well the medication works. You should talk to your doctor before taking fosfomycin if you take:

• the anti-sickness medication metoclopramide
• any hormonal contraception
• medications used to prevent blood clots (anticoagulants)

Fosfomycin 3g sachets can be bought online from a trusted pharmacy or online doctor service, or from the NHS.

Can I buy fosfomycin online?

Yes, you can request fosfomycin online from Asda Online Doctor using our quick and discreet service. You will need to:

1. Complete a short online health assessment for one of our doctors to review.
2. Place your order.
3. If approved, your order will be dispatched to your home address in discreet packaging, or you can choose to collect it from your local Asda Pharmacy 4 hours after a doctor’s approval.
4. If your order is not approved, one of our doctors will contact you via your account with alternative treatment options.

Our service allows you to get prescribed and approved cystitis treatment quickly and easily, without needing to wait for a GP appointment.

Can I buy fosfomycin over the counter?

No, you cannot buy fosfomycin over the counter at pharmacies, as it requires a prescription from a doctor.

Can I get fosfomycin on the NHS?

Yes, you may be able to get fosfomycin on the NHS. You will need to make an appointment with your doctor, who will help determine if it’s the right treatment option for you.

Asda Online Doctor offers nitrofurantoin as an alternative to fosfomycin. Nitrofurantoin is a branded antibiotic that contains the active ingredient nitrofurantoin. It’s usually taken twice a day for 3 days by swallowing a capsule whole with a glass of water. Each capsule contains 100mg of nitrofurantoin.