Buy MacroBID 100mg tablets online to help stop cystitis fast

  • Antibiotic treatment for cystitis
  • Contains nitrofurantoin
  • Available from £19 + prescription fees and delivery costs

Our prices

Strength Quantity Price Stock
100mg6 capsules£19.00Out of Stock
Prices exclude a prescription fee. This treatment requires a quick online consultation,
which a doctor will review to determine if a prescription is appropriate.

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Dr Samantha Miller

Reviewed by Dr Samantha Miller MB ChB
(2017, University of Glasgow)
GMC number: 7561464

Information last reviewed 21/04/2021


What is MacroBID?

MacroBID is an antibiotic containing nitrofurantoin which is used to treat urinary tract infections (UTIs) and cystitis symptoms

How does MacroBID work?

When you take MacroBID, it is filtered through the body directly to the urine where it works by killing the bacteria causing infection. 

How long does it take for MacroBid to work?

MacroBID will typically start to relieve your symptoms within a few days. You'll usually take it for three days and it's important to finish the course of tablets even after you feel better to ensure that the infection is completely gone.

MacroBid MR summary


One capsule, twice a day

Type of Medicine Diaminopyrimidine antibiotic

Deactivates or alters bacterial proteins, preventing key processes such as reproduction and survival of the bacteria

Available Size

6 capsules

Available Strengths


Active Ingredient



From £3.17 per tablet

Side Effects

Can include discolouration of urine, nausea, vomiting, headache, diarrhoea, dizziness, drowsiness, skin rashes


Active ingredients

Nitrofurantoin 100mg modified release is the active ingredient in MacroBID. 

This modified release formulation can be taken less frequently than an immediate release formulation, but is just as effective at treating infection. 

Inactive ingredients

The inactive ingredients are talc, corn starch, lactose, carbopol, povidone, sugar and magnesium stearate. 


How to take MacroBID

MacroBID is usually taken twice a day for three days. You should leave 12 hours between your morning and evening dose. The tablets should be swallowed whole with a glass of water, and preferably with food. It is important to swallow the tablets whole, as crushing or dividing the tablets can cause them to be absorbed too quickly, which could be harmful.

MacroBID dosage

MacroBID is usually given as a 100mg dose taken twice a day. It’s typically prescribed as a three-day course to treat symptoms of urinary tract infection in women.

Can MacroBID be crushed/divided when taking?

MacroBID should be swallowed whole with the capsules intact. If they are crushed or split before taking them then this may prevent the medicine from being absorbed correctly by the body, lessening the effectiveness of the drug.

What should I do if I take too many MacroBID tablets?

If you take an overdose of MacroBID then speak to a doctor or pharmacist for advice.

Side Effects

MacroBID side effects

Like all medicines, MacroBID can cause side effects. Most of them are mild and disappear once you’ve finished the course. you stop taking MacroBID. 

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

Stop taking MacroBID immediately if you experience symptoms of allergic reaction such as difficulty breathing, wheezing, swelling of the face, eyes or lips, a rash affecting your whole body.

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 a treatment or very slowly, especially in elderly patients. This may produce fever, chills, cough and shortness of breath
  • Jaundice (yellowing of the skin or whites of the eyes)
  • Reduced blood cell count which can cause weakness, bruising or make infections more likely
  • Blue or purple colouration of the skin due to low oxygen levels. 
  • 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.

Other side effects are:

Rare (may affect up to 1 in 1,000 people)

  • Loss of consciousness (collapse).

Not known (frequency cannot be estimated from the available data)

  • Nausea or vomiting
  • Headache
  • Loose stools
  • Loss of appetite
  • Stomach pains
  • Diarrhoea
  • Dizziness or drowsiness 
  • Bruising
  • Sore throat
  • Fever
  • Weakness or tingling of the arms or legs
  • Skin rash
  • Short term hair loss
  • Liver inflammation
  • Kidney inflammation
  • Pancreatitis (can cause upper abdominal pain)

How to cope with MacroBID side effects

Drinking lots of water, in small frequent sips, will help to maintain your fluid intake if you experience vomiting or diarrhoea. Get plenty of rest and don't overexert yourself. Painkillers like paracetamol and ibuprofen can be taken alongside MacroBID for headaches. Keep eating small meals at your usual times if your appetite has disappeared and avoid rich, spicy food if you become nauseous. Avoid driving or operating machinery if you feel dizzy or drowsy after taking MacroBID.


You shouldn't take MacroBID if you: 

  • Are allergic to any of the ingredients 
  • Have kidney problems
  • Are at the end of your pregnancy 
  • Have a blood disorder called porphyria 
  • Have G6PD or are breastfeeding a baby with this disorder

Consult your doctor if: 

  • You have diabetes 
  • You have anaemia 
  • You have a condition that causes fatigue 
  • You have kidney problems 
  • Your body is lacking in the glucose-6-phosphate dehydrogenase enzyme 
  • You have a disease of the liver, lungs or nervous system

Drug interactions

The following medicines may interact with MacroBID: 

  • 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 that 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

MacroBID and alcohol

Drinking alcohol will not have an effect on MacroBID. However, it's advised that you avoid drinking alcohol if you have a urinary tract infection. It is important to stay hydrated if you have a UTI and alcohol can make a UTI worse. 

MacroBID and pregnancy

It's generally safe to take MacroBID during pregnancy but it should not be taken too close to childbirth as it may have an effect on the baby's blood. If you are pregnant or breastfeeding then check with your doctor before taking MacroBID.

Does MacroBID cause thrush?

MacroBID could cause thrush if it is used continuously, for example for repeated bouts of UTIs. If this happens then speak to your doctor or pharmacist for appropriate treatment.

Treatment Options

How to avoid UTIs

There are steps you can take to reduce your chances of getting a UTI. Drinking plenty of water flushes out the urethra and dilutes the urine, getting rid of bacteria. Clear, light yellow urine is a healthy sign that your body is adequately hydrated. After using the toilet, always wipe from front to back and pass urine as soon as possible after sexual intercourse. Avoid feminine hygiene products like deodorants, scented soaps and douches as they can cause irritation. If you use a diaphragm or a spermicide method of contraception then you may wish to consider an alternative.

MacroBID vs nitrofurantoin

Nitrofurantoin is the generic name for the antibiotic used to treat urinary tract infections. MacroBID is a brand of nitrofurantoin so it contains the same active ingredient. MacroBID is a modified-release version of nitrofurantoin meaning it only needs to be taken twice a day to have the same effect. 

Can cranberry juice help UTIs?

Cranberries contain a substance called A-type proanthocyanidins which are thought to prevent bacteria from attaching to the urethra. There are some studies which suggest that drinking cranberry juice regularly can help to manage UTIs but there’s not much conclusive evidence. Cranberry juice also has a high sugar content so it should be drunk in conjunction with a balanced diet.


Will my contraception stop working with MacroBID?

Nitrofurantoin does not stop your contraception from working. However, you’re advised to avoid sex until your symptoms have completely cleared up, to maximise the effectiveness of treatment.

What does modified release (MR) mean?

Modified release means that the drug is released into your body over a prolonged period of time. This is in contrast to an immediate-release drug such as trimethoprim. The modified release has the advantage of requiring to be taken less frequently than an immediate-release formulation while having the same effect.

Is MacroBID an antibiotic?

MacroBID is an antibiotic used to treat UTIs (urinary tract infections.) The generic name for this medicine is nitrofurantoin and it is filtered out of your blood into the urine so it can kill the bacteria in the urethra.

Does MacroBID treat kidney infections?

MacroBID can also be prescribed to treat a kidney infection however if you think you have a kidney infection you should seek medical advice, these infections can be serious and may require stronger antibiotics than MacroBID.

Can MacroBid be used for any other infections?

MacroBID is generally only used for urinary tract infections. Your doctor will prescribe you an appropriate antibiotic to treat your infection.

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Easy to use website. A straightforward online consultation with a quick response back. Choice of products for your condition , all with clear descriptions and prices. And an amazing super fast dispatch/delivery. I found treatment for a minor problem in 2 days, sure beats trying to get an bob urgent appointment with my local surgery! Thank you all.


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I moved 150 miles from my GP (to uni) and was unable to go home or visit a walk in for another 2 days due to being at work (12.5 hour shifts). I filled out a quick form - and 1.5 days later I had my antibiotics delivered to my door and I am on the mend. 10/10.