Always follow your doctor's instructions when taking this medicine.
Dosage
Dosage for adults
You'll usually take between 0.5mg and 10mg of dexamethasone a day. For some conditions the dose can go up to 16mg a day.
Dosage for children
Doses are usually lower for a child. The doctor will use your child's height and weight to work out the right dose for them.
For treating croup, your child will usually have a single one-off dose.
Changes to your dose
If you're taking dexamethasone for longer than a few weeks, your dose may change.
Your doctor may reduce your dose once your symptoms start to get better. If your symptoms get worse again, they may increase your dose.
Your doctor will probably reduce your dose gradually before you stop completely. This is to reduce the risk of withdrawal symptoms.
How to take it
You'll usually take dexamethasone once a day. Take it in the morning with or immediately after your breakfast. Do not take it on an empty stomach.
For soluble tablets, dissolve them in a glass of water then drink it all. For other tablets, swallow them whole with a drink of water.
If you're taking dexamethasone liquid, use the plastic syringe or spoon that comes with your medicine to measure out the right dose. 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.
Unless your doctor gives you different instructions, take your full dose in one go. For example, if your dose is 6mg, your doctor may tell you to take three 2mg tablets at the same time.
If your doctor prescribes dexamethasone 2 or 3 times a day, take your last dose before 6pm. It will be less likely to affect your sleep.
For some conditions you may not need to take dexamethasone every day. Your doctor might tell you to take it every other day instead.
How long to take it for
How long you will take dexamethasone for depends on why you need it. Your doctor will tell you how long to take it for.
When used to treat croup in children, your doctor will give a single one-off dose.
For some conditions you may only need to take dexamethasone for a few days or weeks.
However, for other conditions you may need to take it for longer, sometimes for several months.
If you forget to take it
If you take dexamethasone once a day and you miss a dose, take it as soon as you remember. If you do not remember until the following day, skip the missed dose and take the next dose at the usual time.
If you take it 2 or 3 times a day, take the missed dose as soon as you remember, unless it's almost time for your next dose. In this case, skip the missed dose and take the next dose at the usual time.
Never take 2 doses at the same time. Never have an extra dose to make up for a forgotten one.
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
If you take too much
Taking 1 or 2 extra dexamethasone tablets once is unlikely to harm you. If you're worried, talk to your doctor or pharmacist.
If you take too much dexamethasone for more than a few days, it could harm your health.
Urgent advice: Contact 111 for advice now if:
- you take more than your prescribed dose of dexamethasone and you have new symptoms, such as stomach pain or difficulty sleeping
Go to 111 online or call 111. Call 111 if you're asking about a child under the age of 5 years.
If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the dexamethasone packet, or the leaflet inside it, plus any remaining medicine with you.
Stopping dexamethasone
Do not stop taking dexamethasone suddenly, especially if you've been on a high dose for a long time.
Your health condition may flare up again.
You may also get extra side effects including:
- severe tiredness
- weakness
- body aches
- joint pain
Your doctor will probably want to reduce your dose gradually over several weeks to prevent these side effects.
Important
Do not stop taking dexamethasone without talking to your doctor. You'll need to reduce your dose gradually.