Dexamethasone

Sounds like 'dex-a-meth-ah-sone'

Key points about dexamethasone

Dexamethasone is a steroid used to treat and prevent some conditions that cause inflammation.
Dexamethasone works by calming or suppressing your body's immune system.
Find out how to take it safely and possible side effects.

HN 0796 two pharmacists in discussion in dispensary of community pharmacy 950x690

Dexamethasone is used to treat a number of different conditions and symptoms, including:

illnesses associated with inflammation, eg, autoimmune and allergic conditions and some types of cancer
to prevent or reduce nausea (feeling sick) and vomiting (being sick) caused by medicines used for cancer
to prevent allergic reactions caused by some medicines
to treat severe COVID-19 disease
to treat palliative care symptoms (eg, nausea and vomiting, poor appetite, headaches and breathing problems)
to diagnose Cushing's disease (an adrenal gland disorder)
to treat congenital adrenal hyperplasia.

Dexamethasone belongs to a group of medicines known as corticosteroids, which are similar to the steroid hormones your body makes naturally.

In Aotearoa New Zealand dexamethasone is available as tablets in 2 different strengths (0.5 mg and 4 mg) and as a liquid syrup. Dexamethasone also comes as an injection that can be given into the vein (intravenously) or under the skin, using a syringe driver.

The dose of dexamethasone is different for different people, depending on what it's being used for.
Some people only need a single dose or a short course of dexamethasone for a few days, while others may need to take it for longer (weeks to months).
Dexamethasone tablets come in different strengths. Check the strength of your tablets and the dose you're prescribed. You may need to take more than 1 tablet. If you're not sure about your dose, ask your pharmacist.
Always take your dexamethasone exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions.

Timing: Take your dexamethasone tablets with food and with a full glass of water. It's usually taken once a day, straight after breakfast. It's best not to take your dose too close to bedtime because it may keep you awake.
Note: If you're taking dexamethasone for congenital adrenal hyperplasia (CAH) or as a test for Cushing's syndrome, your dose will be taken at bedtime.
Stopping dexamethasone: If you've been taking dexamethasone for more than 3 weeks, stopping it suddenly can cause withdrawal symptoms which can be serious or even life-threatening. Your doctor will reduce your dose gradually. Read more about a steroid withdrawal plan.

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

Other medicines: Dexamethasone interacts with some other medicines, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting dexamethasone and before starting any new products.
Tell all your healthcare providers: It's important to tell all your healthcare providers that you are taking dexamethasone.
Increased risk of infections: Taking dexamethasone for a long time can increase your risk of infections. Tell your doctor if you come into contact with someone who has a contagious illness (eg, chickenpox or measles) or if you feel unwell.
Vaccines: It's safe to have most vaccines, including the flu vaccine, while you're taking dexamethasone. Protecting yourself against infection is important because dexamethasone suppresses your immune system. However, ‘live vaccines’, including MMR (measles, mumps, rubella) or shingles vaccine, should be avoided. Ask your doctor for advice before you have any vaccines while you're taking dexamethasone.

Like all medicines, dexamethasone can cause side effects, although not everyone gets them. Most side effects depend on the dose you're taking and how long you are taking dexamethasone for. Read more about taking steroids long term.

Changes in behaviour and mood

Dexamethasone, in high doses, can cause changes in personality, behaviour and mood for some people, for example:

irritability, agitation and restlessness
sleep problems (insomnia) and nightmares
mood swings and aggression
low mood, depression and even suicidal thoughts.

These symptoms usually start within a few days of starting dexamethasone, but they can happen at any time, even after stopping treatment.

While these symptoms often go away when your dose is reduced or dexamethasone is stopped, stopping dexamethasone must be done slowly as directed. Stopping too quickly can make these symptoms worse. You are at higher risk of mood and behaviour changes if you have had similar reactions to other steroids, or if you have a personal or family history of psychiatric illness.

If you have changes in mood and behaviour, especially depression and suicidal thoughts, tell your doctor immediately or phone Healthline 0800 611 116.

Other side effects

Side effects	What should I do?
Difficulty sleeping	Take dexamethasone in the morning.
Headache Muscle weakness, feeling tired	These are quite common when you first start taking dexamethasone and usually go away with time. Tell your doctor if these bother you.
Increased appetite	Dexamethasone increases your appetite. Follow a healthy, balanced diet. Have an eating plan.
Fluid retention causing swollen ankles and feet	If possible, sit with your feet raised. Avoid salty foods. Tell your doctor if this happens.
Raised blood glucose	Dexamethasone can cause an increase in blood glucose. If you have diabetes, you may need to increase the dose of your diabetes medicine to control your blood glucose. Talk to your doctor about this. Dexamethasone can also cause diabetes in people who are at risk. Your doctor will check your blood glucose levels regularly.
Eye pain and changes to your vision	Tell your doctor immediately or phone Healthline 0800 611 116.
Problems with your stomach, eg, pain, blood in your stool (poo) or dark coloured stool (poo)	Tell your doctor immediately or phone Healthline 0800 611 116.