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  • Macrobid 100mg Prolonged-release - 6 Capsules (Nitrofurantoin)

Macrobid 100mg Prolonged-release - 6 Capsules (Nitrofurantoin)

From £17.99

Medication features

  • Used as a treatment in bacterial infections of the urinary tract
  • Prevent and treat infections of the bladder, kidney
  • One capsule twice a day 
  • 1 week treatment
  • The generic version: Nitrofurantoin


Cystitis Doctor Service

Nitrofurantoin (the active substance in Macrobid) is an antibiotic. It is used to prevent and treat infections of the bladder, kidney and other parts of the urinary tract. Nitrofurantoin works by killing bacteria. It does this by slowing folate synthesis which is required by the bacteria for replication.

You can order Macrobid online from our UK registered online pharmacy and doctor service. To see if you are suitable for this treatment, complete the online assessment and checkout. Our UK registered doctors will review the order and after approval pass the prescription to the Pharmacy team. We will then dispense and dispatch your order to your chosen address.


Cystitis is a urinary tract infection (UTI) that affects the bladder. It's common, particularly in women. It often gets better by itself, but may sometimes be treated with antibiotics.

Some people get cystitis frequently and may need regular or long-term treatment.

Symptoms Of Cystitis Include:

  • pain, burning or stinging when you pee
  • needing to pee more often and urgently than usual
  • pee that's dark, cloudy or strong smelling
  • pain low down in your tummy

Symptoms In Young Children May Also Include:

  • a high temperature – they feel hotter than usual if you touch their neck, back or tummy
  • wetting themselves
  • reduced appetite and being sick
  • weakness and irritability

A good self care guide and information for cystitis is available on the NHS website.

NHS - Cystitis


What Is Cystitis?

Cystitis literally means inflammation of the bladder, however is commonly understood to be an infection of the urine, affecting the bladder.

What Are The Symptoms Of Cystitis?
The most common symptoms of cystitis are:

  • Burning sensations / pain upon urination
  • Frequent urination, or feeling like you need to urinate frequently
  • Cloudy and / or foul-smelling urine
  • Pain just above the pubic bone

Is Cystitis A Common Infection?
Yes, especially women, who are almost 10 times more likely to get cystitis than men. Women are more likely to suffer from cystitis because their urethra is smaller and it is in closer proximity to the anus compared to men.

How Can I Prevent Cystitis?
Bladder infections are mostly contracted through the germs from bowel movements transferring from the anus to the urethra. Some types of bacteria rapidly grow in urine and make the infection much worse. This normally occurs in people who don’t go to the toilet enough which leads to infection due to the bacteria in the bladder system. Cystitis can also be caused by prostate problems and kidney stones in men. Dehydration and not drinking enough liquid can concentrate the urine and lead to infection.

Can Cystitis Cause Any Complications?
Cystitis in men is usually an indication of a more serious problem and requires medical help from your GP. It can also be caused by STIs which can have other complications Men should see their GP if they suffer from cystitis. Women can use treatment without face to face referral but if it doesn’t clear up, medical advice is needed. This is because if left untreated after it hasn’t cleared up, it can lead to a serious kidney infection.

What Treatments Are There For Cystitis?
For milder cases of Cystitis, treatment with potassium citrate sachets may be sufficient. For more stubborn infections, a course of antibiotics such as Trimethoprim, may be required.

What Is The Best Antibiotic For Cystitis?
This depends on what bacteria is causing your infection. The most common type of bacteria which causes uncomplicated UTIs is E coli. The antibiotics which are given to treat this bacteria are Trimethoprim or Nitrofurantoin. If your symptoms do not improve after completing a course of these antibiotics, it is important to see your GP to have your urine tested in case it is a different bacteria which needs a different antibiotic.

What Causes Cystitis?
Cystitis is inflammation of the bladder, usually caused by a bladder infection.

It's not always clear how this happens, but it can be caused by:

  • Having sex
  • Wiping your bottom after going to the toilet – particularly if you wipe from back to front
  • Inserting a tampon or urinary catheter (a thin tube inserted into the urethra to drain the bladder)
  • Using a diaphragm for contraception

Women may get cystitis more often than men because their anus (back passage) is closer to their urethra, and their urethra is much shorter, which means bacteria may be able to get into the bladder more easily.

Can You Buy Over The Counter Treatment For Cystitis?
Sodium bicarbonate or potassium citrate can be purchased over the counter to help alleviate the symptoms of cystitis. These products reduce the acidity of their urine but there's a lack of evidence to suggest they're effective.

Side Effects

Like all medicines, this medicine can cause side effects, although not everybody gets them. Most of them are mild and disappear when you stop taking Macrobid. If you experience any of the side effects detailed below or any other side effects, stop taking Macrobid and consult your doctor.

All medicines can cause allergic reactions although serious allergic reactions are rare. If you notice any sudden wheezing, difficulty in breathing, swelling of the eyelids, face or lips, rash or itching (especially affecting your whole body) STOP taking your medicine and go to a doctor immediately.

If you notice any of the following side effects consult your doctor immediately:

  • Your lungs may react to Macrobid. This may develop quickly, within a week of starting treatment or very slowly, especially in elderly patients. This may produce fever, chills, cough and shortness of breath.
  • Macrobid may cause the liver to become inflamed, producing jaundice (yellowing of the skin or whites of the eyes).
  • Severe reduction in blood cells which can cause weakness, bruising or make infections more likely.
  • Blue or purple coloration of the skin due to low oxygen levels. A condition known as cyanosis.
  • Symptoms of fever, flu, abdominal pain, diarrhoea, blood in your stool and weakness. These could be signs of a condition known as cutaneous vasculitis.
  • Symptoms of fatigue, abdominal pain, joint pain and swelling. These could be signs of a condition known as hepatitis.

Please note that while taking Macrobid your urine may become coloured dark yellow or brown.This is quite normal and not a reason to stop taking the medicine.

For a full list of side effects, please read the patient information leaflet.

If you get any side effects, talk to your doctor, our Rightdose pharmacists or nurse. This includes any possible side effects not listed in this leaflet. You can help to make medicines safer by reporting any side-effects to the Yellow Card Scheme at www.mhra.gov.uk/yellowcard.




Info Leaflet

Before taking any medication, it is important to read the Patient Information Leaflet. You can find information leaflets for your medicines by typing them into the search bar at medicines.org, or by contacting us.

Patient Information Leaflet Macrobid 100mg Prolonged-release Capsules

Other medicines and Macrobid:
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines, including medicines obtained without a prescription. If they are taken with Macrobid their effect or the effect of Macrobid may be changed.

In particular, tell your doctor or pharmacist if you are taking any of the following medicines:

  • Antacids for indigestion (e.g. magnesium trisilicate)
  • Medicines for gout (e.g. probenecid or sulfinpyrazone)
  • Medicines for raised pressure in the eye (glaucoma), such as carbonic anhydrase inhibitors (e.g. acetazolamide)
  • Medicines which make the urine less acidic (e.g. potassium citrate mixture)
  • Medicines for infections, known as quinolones
  • Typhoid vaccine, which is given for the prevention of typhoid.

If you are in doubt about any of these medicines ask your doctor or pharmacist.

Macrobid with food and drink:

Macrobid capsules should be taken at meal times with food or milk. This will help to avoid stomach upset and also to help the absorption.

Pregnancy and breastfeeding:
If you are pregnant or breastfeeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine. As far as it is known Macrobid may be used in pregnancy. However it should not be used during labour or delivery because there is a possibility that use at this stage may affect the baby. If you want to breastfeed, please consult with your doctor first.

Driving and using machines:
Macrobid may cause dizziness and drowsiness. You should not drive or operate machinery if you are affected this way until such symptoms go away.

Macrobid contains lactose:
This medicine contains lactose and sucrose (sugars). If you have been told by your doctor that you are intolerant to some sugars and have to avoid them, contact your doctor before taking this medicine.

  • Do not store above 25˚C.
  • Do not open the container until you are ready to begin taking the course of treatment.
  • Do not use this medicine after the expiry date which is stated on the bottle/label after ‘Exp (MM/YY)’. The expiry date refers to the last day of that month. Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use.
  • These measures will help protect the environment.

Keep this medicine out of the sight and reach of children.


Always take this medicine exactly as your doctor or pharmacist has told you. You should check with your doctor or pharmacist if you are not sure.

Adults and children over 12 years old:

The normal dosage depends on the type of infection you have and instructions should be written on the label provided by the pharmacist. Consult your pharmacist or doctor if these instructions are not clear.

The usual doses are:

For treatment of bladder infections:

  • One capsule twice a day for seven days.
  • Macrobid should be taken with food or milk.

For prevention of bladder infections during surgery:

  • One capsule twice a day on the day of the operation and three days thereafter.

Use in children

  • Macrobid is not recommended for children under 12 years of age.

Medical Checks

Your doctor will watch carefully for any effects on the liver, lungs, blood or nervous system. Nitrofurantoin Tablets may interfere with the results of some tests for glucose in the urine. 


  • Tablets should be swallowed whole. The score line is not intended for breaking the tablet.
  • Macrobid tablets should always be taken with food or milk. Taking this medicine with food or milk makes it work more effectively.

If you take more Macrobid than you should:
Consult your doctor or pharmacist immediately or go to the emergency department of the nearest hospital. Always take any leftover capsules with you, as well as the container and label, so that the medical staff know what you have taken.

If you forget to take Macrobid:
Do not worry. If you remember later on that day, take that day’s dose as usual. If you miss a whole day’s dose take the normal dose on the next day. Do not take a double dose to make up for a forgotten capsule. If you are not sure, ask your doctor or pharmacist.

If you stop taking Macrobid:
Your doctor will tell you how long to take the treatment. Do not stop earlier than you are told, even if you feel better. If you have any further questions on the use of this medicine, ask your doctor, pharmacist or nurse.


Do not take Macrobid Tablets if:

  • you are allergic to Nitrofurantoin, other medicines containing nitrofurantoin or any of the other ingredients
  • you have a disease of the kidneys which is severely affecting the way they work (ask your doctor if you are not sure)
  • you are in the final stages of pregnancy (labour or delivery) as there is a risk that it might affect the baby
  • you have porphyria (blood disorder)
  • you are a patient with G6PD (glucose-6-phosphate dehydrogenase) deficiency
  • your child is under three months of age
  • you are breastfeeding a baby with suspected or known deficiency in an enzyme called G6PD (glucose-6-phosphate-dehydrogenase).

Tell your doctor if you are not sure about any of the above.

Warnings and precautions:

Talk to your doctor or pharmacist before taking Macrobid tablets if:

  • you have diabetes
  • you are suffering from any illness causing severe weakness
  • you have anaemia (a decrease in red blood cells causing pale skin, weakness and breathlessness) or a lack of vitamin B or abnormal levels of salts in your blood (your doctor will be able to advise you)
  • you have a history of allergic reactions
  • if you have any problems with your kidneys.

The above conditions may increase the chance of developing a side effect which results in damage to the nerves, causing altered sense of feeling like pins and needles.

  • you lack an enzyme (body chemical) called glucose-6-phosphate dehydrogenase which causes your red blood cells to be more easily damaged (this is more common in black people and people of Mediterranean, Middle Eastern or Asian origin. Your doctor will know)
  • you have any disease of the lungs, liver or nervous system. If you need to take Nitrofurantoin Tablets for a number of months, your doctor may want to regularly check how your lungs and liver are working
  • you have false positive results on testing your urine for glucose
  • your urine is dark yellow or brown coloured.

Talk to your doctor if you experience fatigue, yellowing of the skin or eyes, itching skin rashes, joint pain, abdominal discomfort, nausea, vomiting, loss of appetite, dark urine and pale or grey coloured stools. It may be symptoms of liver disorder.


What Macrobid contains:

The active substance is 100mg nitrofurantoin in each capsule.

The other ingredients are talc, corn starch, lactose, carbopol, povidone, sugar and magnesium stearate. The capsule shell contains gelatin, quinoline yellow (E104), titanium dioxide (E171) and FD&C Blue No.2 (E132). The printing ink contains shellac, propylene glycol (E1520), titanium dioxide (E171) black iron oxide (E172), ammonium hydroxide (E527) and simethicone.

What Macrobid looks like and contents of the pack:

MacroBID 100mg capsule has an opaque blue cap and opaque yellow body and bears the monogram “GS 100”.

The capsules are available in blister strips of 14.

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