Sounds like 'nor-flox-a-sin'

Easy-to-read medicine information about norfloxacin – what it is, how to take norfloxacin safely and possible side effects.

Type of medicine

Also called

  • Antibiotic (used to treat infections of the urinary tract)
  • Arrow-Norfloxacin®

What is norfloxacin?

  • Norfloxacin is an antibiotic that is used to treat infections such as bladder infections.
  • It works by killing or stopping the growth of the bugs that cause the infection.
  • It is part of the quinolone group of antibiotics.


  • 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.
  • 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.

How to take norfloxacin

  • Swallow the tablets whole with a glass of water. Do not take with milk.
  • Norfloxacin is best taken on an empty stomach, about 1 hour before food, OR 2 hours after food.
  • Take norfloxacin at the same times each day.
  • Limit or avoid drinking alcohol while taking norfloxacin.
  • Keep taking norfloxacin until you finish all the tablets, for as long as your doctor or pharmacist tells you to.
  • Do not stop taking norfloxacin, even if you feel better after a few days, unless your doctor tells you to.
  • If you forget to take norfloxacin, 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.

Possible side effects

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

Side effects What should I do?
  • Feeling sick, nausea, stomach pains
  • Mild diarrhoea (runny poos)
  • Headache
  • Feeling dizzy
  • This is quite common when you first start taking norfloxacin and usually goes way with time.
  • Tell your doctor if this continues.
  • Dizziness
  • Sleepiness
  • Be careful when driving or using tools until you know how this medicine affects you
  • 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.


  • 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:
    • theophylline (eg, Neulin)
    • antacids (eg, Mylanta) or multivitamins. These should be taken at least 4 hours before or 2 hours after taking each dose of norfloxacin.

 Learn more

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr J Bycroft. Health Navigator NZ Last reviewed: 01 Apr 2015