Cefalexin for infection

About cefalexin

What is cefalexin used for?

Cefalexin is a type of antibiotic used to treat bacterial infections such as urinary tract infections, skin infections, chest and throat infections, ear infections and dental infections.

It is suitable for adults and children and can be taken during pregnancy.

Some people who are allergic to penicillin antibiotics may not be able to take cefalexin, so make sure your doctor knows if you have ever had an allergic reaction to any other antibiotic.

Cefalexin treats an infection by killing the bacteria that are causing it.

Side effects of cefalexin

Common side effects of cefalexin are:

• Diarrhoea.

• Feeling sick (nausea).

• Indigestion.

• Stomach ache.

• Thrush.

You will find a full list in the manufacturer's information leaflet supplied with the medicine.

The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

How to manage cefalexin side effects

If you experience any other symptoms which you think may be due to the antibiotic, please speak with your doctor or pharmacist for further advice.

Who should not take cefalexin?

Some medicines are not suitable for people with certain conditions. Before starting cefalexin it is important that your doctor knows:

• If you have ever had an allergic reaction to a medicine. It is particularly important that you tell your doctor if you have had a bad reaction to a penicillin or cephalosporin antibiotic.

• If you have any problems with the way your kidneys work.

• If you are pregnant, trying for a baby or breastfeeding. Although cefalexin is not known to be harmful to babies, it is still important that you tell your doctor if you are expecting or breastfeeding a baby.

• If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

How to take cefalexin

• Read the leaflet inside the pack before starting cefalexin. It explains how the antibiotic works and lists possible side effects.

• Take cefalexin 2-4 times a day, as directed by your doctor. Check the label for your exact dose and timing.

• For children: if using liquid cefalexin, carefully measure each dose as instructed.

• Treatment usually lasts 5-7 days, but your doctor may adjust this. Always follow their advice.

• For UTI prevention: you may take one dose daily, usually in the evening.

• You can take cefalexin before or after food, but it may work a bit faster before meals.

• Space doses evenly through the day and complete the full course, even if you feel better.

• If you miss a dose, take it as soon as you remember. Do not take twice to make up for a missed one.

Getting the most from your treatment

• Tell your doctor or healthcare provider if you’re taking cefalexin before any operation or medical test, as it can affect some test results.

• Antibiotics can sometimes cause thrush (oral or vaginal). If this happens, speak to your doctor or pharmacist.

• If you take the contraceptive pill and have vomiting or diarrhoea for more than 24 hours while on antibiotics, the pill may be less effective. Ask your doctor or pharmacist about extra contraception. No extra precautions are needed if symptoms last less than 24 hours.

• Cefalexin can stop the oral typhoid vaccine from working properly. Tell the person giving you any vaccines that you’re taking this antibiotic.

How to store cefalexin

• Keep all medicines out of the reach and sight of children.

• Store tablets and capsules in a cool, dry place, away from direct heat and light.

• If you have been given liquid medicine, store it in a refrigerator. It will have been made up freshly by the pharmacy and lasts for 14 days, so please remember to check the expiry date, and do not use it after this date.

Important information about all medicines

Frequently asked questions

How quickly does cefalexin work?

Cefalexin usually starts to work within an hour after taking the first dose. Most people notice improvement in symptoms, such as reduced pain, fever, or redness, within the first 1-2 days of treatment.

Is cefalexin safe to use during pregnancy?

Yes, cefalexin is considered safe to use during pregnancy as there is no evidence that it causes harm to the baby. However, always let your doctor or midwife know you are pregnant before taking cefalexin.

Does cefalexin contain penicillin?

No, cefalexin does not contain penicillin. However it is a cephalosporin antibiotic, which is chemically related to penicillin. People who are allergic to penicillin may also be allergic to cefalexin, so it is important to inform your doctor if you have a penicillin allergy before taking cefalexin.

Can you drink alcohol with cefalexin?

Yes, you can drink alcohol with cefalexin. However, it is advised to only drink in moderation as alcohol may increase side effects such as stomach upset, dizziness, or drowsiness.

Can cefalexin cause a rash?

Yes, cefalexin can cause a rash as a side effect and is usually a sign of an allergic reaction. If you develop a mild rash, contact your doctor for advice. If you have trouble breathing or swelling of the face, lips, tongue, or throat, seek medical help immediately.