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Cefalexin

Sounds like 'kef-a-lex-in'

Key points about cefalexin

Cefalexin is an antibiotic used to treat different infections caused by bacteria.
Cefalexin is also called Cefalexin (Sandoz®, Flynn®) and Cefalexin ABM®.
Find out how to take it safely and possible side effects.

HN 0891 mother and young son receiving counselling from pharmacist

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Cefalexin is an antibiotic belonging to the cephalosporin family. It's used to treat infections caused by bacteria, such as infections of the urinary tract, skin or chest. It can also be used for dental infections or ear infections.

It works by killing or stopping the growth of bacteria (bugs) which gets rid of the infection.

Cefalexin is sometimes used to prevent infections. It doesn't work against infections caused by viruses.

In Aotearoa New Zealand cefalexin is available as capsules (250 mg or 500 mg) and liquid (125 mg or 250 mg in 5 ml).

The dose of cefalexin will be different for different people depending on the type of infection and your age.
The usual adult dose is 500 mg, 3 or 4 times a day. Some people may need a larger dose.
The dose for children will depend on their body weight. It may be given 2, 3 or 4 times a day.
Your healthcare provider will advise you how long to take cefalexin for (usually 5 to 7 days).
Always take your cefalexin exactly as your healthcare provider has told you. The pharmacy label on your medicine will tell you how much cefalexin to take, how often to take it, and any special instructions.

Timing of your doses: You can take cefalexin with or without food. Try to space your doses evenly throughout the day.
- 2 times a day – this should be in the morning and in the evening.
- 3 times each day – this should be in the morning, early afternoon and at bedtime.
- 4 times each day – this should be about 4 hours apart, for example 7am, 11am, 3pm and 7pm.
Capsules: Swallow your capsule with a drink of water. Don't chew them.
Liquid cefalexin: Shake the bottle well and use an oral syringe or measuring spoon to measure each dose. For information on how to give cefalexin to children, see cefalexin information for parents and carers.(external link)
Missed dose: If you forget to take your dose at the correct time, take it as soon as you remember. Try to take the correct number of doses each day. Don't take 2 doses at the same time to make up for a forgotten dose.
Finish the course: It's best to take the whole course of antibiotics for the number of days your healthcare provider has told you to. Don't stop taking it, even if you feel your infection has cleared up.

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

Penicillin allergy: Let your healthcare provider know if you are allergic to penicillin or any other antibiotics. You may be more likely to have an allergic reaction to Cefalexin if you're allergic to any penicillins.
Cefalexin liquid: Store your cefalexin liquid in the fridge and discard any remaining liquid after your course is finished. You can return any unused medicine to your pharmacy.
Alcohol: Cefalexin doesn't directly interact with alcohol. This means that most people could have the occasional drink while taking it without any serious problems. However, if cefalexin makes you feel sick (nausea), don't drink alcohol as it will make you feel worse.
Driving: Cefalexin can make you feel dizzy. Be careful when driving or using tools until you know how this medicine affects you.
Pregnancy or breastfeeding: Talk to your healthcare provider if you're pregnant, planning a pregnancy or want to breastfeed.
Other medicines:
- cefalexin interacts with some medicines, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting cefalexin and before starting any new products.
- If you're taking the contraceptive pill, you don't need to use additional contraception if you're taking cefalexin. But if you have diarrhoea (runny poo) or vomiting (being sick) that lasts more than 24 hours, absorption of the contraceptive pill may be affected. If you have diarrhoea or vomiting, ask your healthcare provider for advice.

Like all medicines, cefalexin 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 being sick (vomiting) Dizziness, headache	Try taking cefalexin with food. Tell your doctor if these bother you. If you've been vomiting and you're taking the oral contraceptive pill, let your healthcare provider know.
Diarrhoea (runny poo)	This may settle after a few days. Drink more fluids and eat simple foods such as toast and pasta. Tell your doctor if your diarrhoea is severe or lasts more than a few days. If you have a lot of diarrhoea and you're taking the oral contraceptive pill, let your healthcare provider know.
Small white patches in your mouth or a white furry tongue (oral thrush) Vaginal itching, soreness or discharge (vaginal thrush)	Ask your healthcare provider for advice.
Signs of problems with your liver such as yellow skin and eyes, dark urine and 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	This is rare. Tell your doctor immediately or ring Healthline 0800 611 116.