Sounds like 'nor-flox-a-sin'

Norfloxacin is an antibiotic that is used to treat infections of the urinary tract. Find out how to take it safely and possible side effects. Norfloxacin is also called Noroxin.

Type of medicine Also called
  • Antibiotic 
  • Quinolone antibiotic
  • Arrow-Norfloxacin®
  • Noroxin®

What is norfloxacin?

Norfloxacin is an antibiotic that is used to treat infections of the urinary tract such as bladder infection (cystitis) and infection of the prostate (prostatitis). It works by killing or stopping the growth of bacteria (bugs). Like all antibiotics, norfloxacin is not effective against infections caused by viruses.

In New Zealand, norfloxacin is available as tablets (400 mg).   


  • The usual dose of norfloxacin is 1 tablet (400 mg) twice a day.
  • Your doctor will advise you on how long to take norfloxacin for (usually 3 to 7 days). Some people may need to take it for longer.
  • Always take your norfloxacin exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much nitrofurantoin to take, how often to take it, and any special instructions. 
  • Note: norfloxacin is not usually given to children because it can affect growing joints.

How to take norfloxacin

  • Timing: Norfloxacin is best taken on an empty stomach, about 1 hour before food, or 2 hours after food. Take your norfloxacin dose at the same times each day about 10–12 hours apart, for example between 7–8 am, and between 7–8 pm. Swallow the tablets whole with a glass of water. Do not take with milk.
  • Missed dose: If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.

It is best to take the antibiotic for the number of days your doctor has told you to. Do not stop taking it, even if you feel your infection has cleared up. Talk to your doctor first.

Precautions – while taking norfloxacin

  • Do not drink milk or take indigestion remedies or medicines containing iron or zinc (such as multivitamin tablets) during the 2 hours before you take norfloxacin, or during the 2 hours after you have taken a dose. These interfere with the way norfloxacin is absorbed by your body, and stop it from working fully.
  • Norfloxacin can make your skin more sensitive to sunlight, so it is important to cover up and wear sunscreen if you spend time outside, especially in the summer months.
  • Avoid alcohol while taking norfloxacin.

Precautions before starting norfloxacin

  • Are you pregnant, planning a pregnancy orbreastfeedingg?
  • Do you have kidney problems?
  • Do you have epilepsy?
  • Do you have any problems with your heart?
  • Do you have myasthenia gravis (causes tired and weak muscles)?
  • Are taking any other medicines? This includes any medicines you are taking which you can buy without a prescription, as well as herbal and complementary medicines.

If so, it’s important that you tell your doctor or pharmacist before you start norfloxacin. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

What are the side effects of norfloxacin?

Like all medicines, norfloxacin can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Tendon problems

Norfloxacin can cause tendon problems such as tendinitis or tendon rupture. The Achilles tendon is most frequently involved but other sites can also be affected. You are at higher risk if you are over 60 years of age, taking steroid therapy (such as prednisone), have chronic kidney disease or have had a kidney, heart or lung transplant. Let your doctor know immediately if you get pain and swelling in your joints. This can happen as early as the first few hours after the first dose and as late as six months after treatment.

Other problems

Side effects What should I do?
  • Feeling sick, nausea, stomach pains
  • Mild diarrhoea (runny poos)
  • Headache
  • Tinnitus or ringing in the ears
  • Problems sleeping
  • Sore muscles
  • This is quite common when you first start taking norfloxacin and usually goes way with time
  • Tell your doctor if this continues
  • Dizziness
  • Sleepiness
  • Confusion or anxiety
  • Be careful when driving or using tools until you know how this medicine affects you
  • Avoid alcohol
  • Problems with your heart rate
  • Seizures
  • Tell your doctor immediately or ring HealthLine 0800 611 116 
  • Signs of problems with your liver such as yellowing of the skin or eyes, dark urine, pain in the abdomen
  • Tell your doctor immediately or ring HealthLine 0800 611 116
  • Allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing such as chest tightness, or wheezing.
  • Tell your doctor immediately or ring HealthLine 0800 611 116 
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product


Norfloxacin may interact with a few important medications or herbal supplements, so check with your doctor or pharmacist.

Also, check with a pharmacist before taking over-the-counter medicines such as antacids or multivitamins. These should be taken at least 4 hours before or 2 hours after taking each dose of norfloxacin.

Learn more

Arrow-Norfloxacin Medsafe Consumer Information Sheet 
Norfloxacin New Zealand Formulary Patient Information


  1. Quinolones - a tendoncy to rupture Medsafe, 2012
  2. Norfloxacin New Zealand Formulary

Additional resources for healthcare professionals

Upfront – antimicrobial resistance in New Zealand – what is my role in primary care? BPAC, NZ, 2013
Antibiotics guide BPAC, NZ, 2013
Quinolone antibiotics – limit use BPAC, NZ, 2011

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 25 Feb 2019