Sounds like 'CEF-a-klor'

Key points about cefaclor

  • Cefaclor is an antibiotic used to treat different infections caused by bacteria.
  • Cefaclor is also called Ranbaxy-Cefaclor®
  • Find out how to take it safely and possible side effects.
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Cefaclor is an antibiotic used to treat infections caused by bacteria, such as infections of the urinary tract, skin or chest. It can also be used for ear and sinus infections. It works by killing or stopping the growth of bacteria (bugs) and gets rid of the infection. Cefaclor does not work against infections caused by viruses. In New Zealand, cefaclor is available as capsules and liquid.

  • The dose of cefaclor will be different for different people depending on the type of infection and your age. 
  • The usual adult dose is 250 mg three times a day.
  • The dose for children will depend on their body weight; it is usually given three times a day.
  • Your doctor will advise you how long to take cefaclor for (usually 5 to 7 days, but can be up to 10 days).
  • Always take your cefaclor exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much cefaclor to take, how often to take it, and any special instructions.

  • Timing of your doses: Cefaclor is usually given 3 times a day. Try to space the doses evenly throughout the day such as the first thing in the morning, early afternoon and at bedtime. You can take cefaclor with or without food. Swallow your capsule with a glass of water. Do not chew them.
  • Missed dose: If you forget to take your dose at the correct time, take one as soon as you remember. Try to take the correct number of doses each day, leaving at least 4 hours between doses. Do not take two doses at the same time to make up for a forgotten dose.
  • Finish the course. It is best to take the whole course of antibiotics 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. 

Here are some things to know when you're taking cefaclor. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Cefaclor does not have direct interaction with alcohol. This means that most people could have the occasional drink while taking it without any serious problems. However, if cefaclor makes you feel sick (nausea), do not drink alcohol as it will make you feel worse.
  • If you are taking the contraceptive pill, you do not usually need to use additional contraception if you're taking cefaclor. But if the antibiotic or the illness they're treating cause diarrhoea or vomiting, lasting more than 24 hours, absorption of the contraceptive pill may be affected. If this happens, ask your doctor or pharmacist for advice about contraception over the following few days.  

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

Side effects What should I do?
  • Feeling sick (nausea) or vomiting
  • Dizziness, headache
  • Try taking cefaclor with food.
  • Tell your doctor if troublesome.
  • If you have been vomiting and are also taking the oral contraceptive pill, let your doctor or pharmacist know.
  • Diarrhoea (runny poos)
  • This may settle after a few days.
  • Tell your doctor if troublesome.
  • If you have diarrhoea and are also taking the oral contraceptive pill, let your doctor or pharmacist know.
  • Vaginal itching, soreness or discharge (thrush)
  • Ask your doctor or pharmacist for advice.
  • Joint pain
  • Tell your doctor immediately or ring HealthLine 0800 611 116
  • Signs of problems with your liver such as yellow eyes and skin, dark urine, stomach pain. 
  • Tell your doctor immediately or ring HealthLine 0800 611 116
  • Signs of allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing
  • 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(external link)

Cefaclor(external link) New Zealand Formulary Patient Information



5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ, 2019 English(external link), te reo Māori(external link)


Cefaclor paediatric dose calculator


  1. Cefaclor(external link) New Zealand Formulary
  2. Antibiotics: choices for common infections(external link) BPAC, 2017

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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