Cystitis antibiotics - Medical information

About cystitis

Cystitis, also known as a water infection or urinary tract infection (UTI), can be uncomfortable and troublesome. Some women are prone to repeated episodes of cystitis. Men rarely suffer from cystitis, but when they do it tends to be more serious. The treatment offered here is NOT for men, only for women who are prone to repeated uncomplicated water infections.

Antibiotics for cystitis from us

We supplies only standby antibiotics, either trimethoprim or nitrofurantoin, to keep in reserve to take if an infection develops. Standby antibiotic treatment is only for those women who are prone to cystitis and have already been diagnosed with it in the past. You should only use this treatment if you are confident you can recognise the symptoms when you get them.

How to choose whether to order trimethoprim or nitrofurantoin is discussed below. A short questionnaire must be completed after choosing the required antibiotic. This ensures the treatment is correct for you and that you are aware of how to use it.

This postal service is not for the treatment of cystitis that has already started. If cystitis symptoms have already started contact your GP surgery, out-of-hours service, a local pharmacy, telephone 111 or visit NHS 111 online for advice. This will guarantee there is no delay in starting treatment.

Patients ordering antibiotics from we are required to provide their GP details. We will inform your surgery each time treatment is supplied. This allows GPs to monitor overall treatment.

Simple uncomplicated cystitis

Simple cystitis is the term used to describe an infection in the urine which is causing mild to moderate symptoms, where the infection has not spread to the kidneys, and is not causing severe generalised symptoms. Self-treatment with standby antibiotics is usually effective for simple cystitis. Symptoms should improve within 24 hours. Symptoms of simple cystitis include:

  • Burning and soreness when passing water (doctors call this dysuria).
  • A need to pass water frequently, sometimes many times in an hour.
  • A need to run to the toilet quickly and and not being able to hold urine for longer periods.
  • The urine may be brown or murky and may smell strong.
  • People with cystitis often feel uncomfortable and slightly unwell.

Severe or complicated cystitis

Women who have a severe urine infection, a past history of serious urinary infection, or worsening symptoms once they have started treatment, should consult their regular doctor straight away. They should not self-treat, even with antibiotics, unless they are under the supervision of their regular doctor. This also applies to women who are pregnant, or have kidney or bladder abnormalities, kidney stones, or reduced kidney function.

Severe symptoms arise when infection moves up from the bladder to the kidneys or when infection affects the whole body (sepsis). Infection of the kidneys is known as pyelonephritis and requires urgent medical attention and sometimes hospital treatment.

Any of the following symptoms may indicate serious pyelonephritis:

  • Back pain (indication of possible infection in the kidney).
  • Fever (high temperature, flushing, shivering, feeling hot and cold).
  • Nausea and sickness and loss of appetite.
  • Generalised aching and flu-like feeling.

In addition, symptoms of sepsis also include:

  • Rapid breathing.
  • Feeling dizzy or faint.
  • Confusion or disorientation.
  • Nausea, vomiting, diarrhoea.
  • Feeling cold and clammy.
  • Pale or mottled skin.
  • Not passing urine all day.

All the above symptoms suggest something more serious than a simple cystitis and the need to seek medical advice straight away - telephone NHS 111, visit NHS 111 online, or contact your regular GP or out-of-hours service, or in emergency telephone 999 in the UK.

Cystitis in older women

Resistance to antibiotics can be more common as women get older. We recommends sending a urine specimen to your GP for testing if you are over 65 years and have cystitis. Trimethoprim is not recommended if you are over 75 years - nitrofurantoin can still be used.

Prevention of cystitis

The frequency of cystitis infections can be reduced by several measures:

  • Wear underwear made from natural fibre rather than synthetics.
  • Avoid wearing tight underwear, tight jeans and trousers.
  • Drink plenty of water (1.6 litres, 3 pints, 6 glasses or mugs) each day.
  • Go to the toilet as soon as you feel the need to, and relax your pelvic floor to ensure complete bladder emptying.
  • Pass water before, and immediately after, intercourse.
  • Avoid douching (washing the vagina out internally).
  • Shower rather than bath and don't use perfumed soap, bubble bath, or talc around genitals.
  • Wipe from front to back after passing stools (poo).
  • Try not to get constipated.
  • Avoid spermicidal contraceptives (used with caps, diaphragms, and sometimes condoms).
  • Cranberry juice or cranberry tablets (2 daily) or D-mannose (1 gram twice daily) may help for some people.

Self treatment without antibiotics

Sometimes cystitis will go away by itself in a few days, without antibiotic treatment.

  • Increase the amount of water you are drinking each day (to 2-3 litres or 4-5 pints a day, or 10-12 glasses or mugs).
  • Avoid alcohol, caffeine, and fizzy drinks which can irritate the bladder.
  • Take paracetamol or ibuprofen for pain if necessary.

There is no evidence that cranberry or citrate or bicarbonate cystitis sachets will help, once symptoms have started. Sachets must not be taken at the same time as nitrofurantoin as they will prevent it working.

If symptoms are mild, self-treatment and 'wait-and-see' for a few days may be the best approach. If symptoms are severe or worsening antibiotics are usually preferred. Women who have repeated infections will usually know if their symptoms are likely to stop on their own.

Recurring infection

Doctors often cannot find out why a woman is getting repeated episodes of cystitis. When a woman first starts having these infections, tests are sometimes carried out. These tests are often normal. After the menopause, the natural defence to cystitis is reduced and sometimes doctors will prescribe oestrogen in the form of vaginal pessaries or cream which can reduce the number of episodes of cystitis. In some women cystitis is associated with recent intercourse, and a doctor may suggest taking one antibiotic tablet after intercourse to prevent cystitis. In others it can be associated with stress, which probably reduces natural immunity.

However, most water infections seem to start for no particular reason. If a woman has repeated episodes of cystitis, and the pattern of infection and symptoms are not changing, doctors will often just treat with antibiotics as each infection arises.

Choosing between trimethoprim or nitrofurantoin

Trimethoprim and nitrofurantoin are both antibiotics. They are both effective in treating cystitis, although there is increasing antibiotic resistance to trimethoprim. Nitrofurantoin is now (2023) the most widely prescribed first line treatment for cystitis. A first-line treatment is the one that is usually recommended and prescribed first by doctors. Up to 30% of bacteria which cause water infections are currently resistant to trimethoprim. The amount of bacterial resistance to particular antibiotics varies from one part of the country to another.

Antibiotics for cystitis are taken once every 12 hours for 3 days. Please note that the manufacturer's Patient Information Leaflet for nitrofurantoin states 7 days - a standard course of cystitis treatment has now been reduced to 3 days.

Women who get repeated water infections may well already know which antibiotic tends to work best for them. Nitrofurantoin is often a good first choice, because in general there is less bacterial resistance, but many infections still respond well to trimethoprim. Repeated use of either antibiotic may encourage antibiotic resistant infections. In particular using trimethoprim again within 3 months is more likely to lead to resistance.

Some women may find that one or other of nitrofurantoin or trimethoprim is not suitable for them or causes more side-effects.

Remember, if you already have an infection contact your GP surgery, NHS 111, a pharmacist, or out-of-hours service.

For more information about each antibiotic see the nitrofurantoin page and the trimethoprim page. There are also links below to the manufacturer's leaflets supplied with these medicines.

Other antibiotics which can be used to treat cystitis include pivmecillinam, fosfomycin, cefalexin, and co-amoxiclav (Augmentin). These antibiotics tend to be reserved for more serious infections or special situations and are not available from us.

Response to treatment

Simple cystitis should improve greatly within 24 hours of starting antibiotics. If symptoms are not improving in the first 24 hours, or have not gone completely at the end of 3 days, medical advice is needed. A urine sample may need to be sent for laboratory testing. If symptoms worsen rather than improve, medical advice is needed straightaway.

Antibiotic guardianship

To combat antibiotic resistance please:

  • Only use antibiotics when needed
  • Never share antibiotics
  • Always complete course as instructed
  • Take unused medicine to local pharmacy for disposal