Dosage
Clarithromycin tablets come in 250mg or 500mg strengths. The granules come in 125mg or 250mg sachets. The liquid comes in strengths of 125mg in 5ml or 250mg in 5ml.
The usual dose of clarithromycin is 250mg to 500mg twice a day, although the dose may be lower for children or if you have kidney problems.
If your doctor prescribes slow-release tablets, the usual dose is 500mg once a day. Sometimes the dose is higher for more severe infections. These tablets release the medicine slowly, which means that 1 dose a day is enough.
Try to take your medicine at the same time every day.
How to take it
Clarithromycin comes in different forms and strengths, and there are different ways to take it:
How to take tablets
Swallow the tablets whole with a drink of water. Do not chew or break them.
You can take them with or without food.
How to take granules
Open the pack (or packets) and mix the granules with a small amount of water to drink.
The granules can be used for children or people who find it difficult to swallow tablets.
How to take liquid
The liquid can be used for children or people who find it difficult to swallow tablets.
If you or your child are taking clarithromycin liquid, your pharmacist will usually make it up for you.
The medicine will come with a plastic syringe or spoon to help you take the right amount. If you do not have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.
How long to take it for
For skin problems such as cellulitis, you may have to take the medicine for about 7 days before you see any improvement.
If you have a Helicobacter pylori infection, even if the bacteria are no longer in your stomach, it can take some time before you feel better.
Your doctor will usually give you a medicine to reduce stomach acid, such as omeprazole or lansoprazole, while the ulcer heals. You should start feeling better when you finish the treatment to reduce your stomach acid.
Important
Carry on taking this medicine until the course is finished, even if you feel better. If you stop your treatment early, your infection could come back.
If you forget to take it
If you forget to take a dose, take it as soon as you remember, unless it's nearly time for your next dose. If this happens, just leave out the missed dose and take your next dose at the usual time.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to remember to take your medicine.
If you take too much
Taking an extra dose of clarithromycin is unlikely to harm you or your child. However, it may give you temporary side effects, like stomach pain, feeling and being sick (nausea and vomiting), and diarrhoea.
Talk to your pharmacist or doctor if you're worried or get severe side effects, or if you or your child take more than 1 extra dose.