Dexamethasone: a steroid medicine

Dr Roger Henderson
·15-min read
Photo credit: gilaxia
Photo credit: gilaxia

From Netdoctor

What is dexamethasone?

Dexamethasone is a type of medicine known as a corticosteroid. These medicines are man-made versions of the corticosteroid hormones, cortisol and aldosterone, produced naturally by the adrenal glands.

They are often referred to as steroids. Dexamethasone is a generic medicine, available as tablets, liquid, eye drops and injection.

What is dexamethasone used for?

Dexamethasone tablets and liquid are used mainly for the following reasons:

  • Returning hormone levels to normal in a disorder of the adrenal glands called congenital adrenal hyperplasia.

  • Diagnosing the cause of Cushing's syndrome (called a dexamethasone suppression test).

  • Reducing swelling in the brain or raised pressure inside the skull associated with brain tumours.

  • Preventing sickness and vomiting associated with chemotherapy for cancer.

  • Helping with symptoms in palliative care of people with cancer, for example loss of appetite, pain caused by tumours that press on a nerve, breathing problems or swallowing difficulties.

Dexamethasone can now also be used in treating people who are severely ill with COVID-19.

Dexamethasone suppresses part of your immune system and reduces inflammation and swelling and so may also be used for many different diseases and conditions, including those below:

Dexamethasone may be given by injection if you can't take it by mouth.

Dexamethasone can also be given by injection directly into a joint, or the soft tissue around a joint, to reduce inflammation, for example in rheumatoid arthritis, tennis elbow, golfer's elbow or bursitis.

Dexamethasone eye drops are used for reducing local inflammation in the eyes.

How does dexamethasone work?

Dexamethasone is a type of medicine known as a corticosteroid. These medicines are man-made versions of the corticosteroid hormones, cortisol and aldosterone, produced naturally by the adrenal glands.

Corticosteroids have many important functions on every organ system. If the body's natural level of steroid hormones is too low because the adrenal glands are not producing enough hormones, this must be treated with replacement therapy to allow the body to function normally. Dexamethasone is used specifically to treat a disorder of the adrenal glands called congenital adrenal hyperplasia. People with this condition lack an enzyme needed by the adrenal glands to produce cortisol and aldosterone, and without these hormones the adrenal glands produce too many male sex hormones (androgens). This causes early (or inappropriate) appearance of male characteristics. Taking dexamethasone daily helps return the hormone levels to normal.

Corticosteroid hormones are also involved in controlling inflammatory responses in the body. Dexamethasone reduces inflammation by stopping cells from releasing chemicals that normally help produce immune and allergic responses. This can help control a wide number of disease states that involve excessive inflammation, including severe allergic reactions and inflammation of the joints in arthritis.

Dexamethasone also decreases the numbers of white blood cells circulating in the blood and both actions make it useful for treating autoimmune diseases caused by the immune system attacking the body's own tissues, such as many of those listed above. It is also useful for treating certain types of blood cancer where there is excessive production of certain white blood cells.

Dexamethasone risk factors

Who should be careful using dexamethasone? Your doctor will only prescribe dexamethasone if the benefits of taking it outweigh the risks of not treating your condition, but in these situations a lower dexamethasone dose may be needed, or your doctor might want you to have regular check-ups or extra monitoring. Dexamethasone should be used with caution in the following:

  • Elderly people, children and adolescents. Steroid side effects are more likely in the very young and very old. Long-term use of dexamethasone also has the potential to slow growth in children, so if your child needs to take this steroid for a long time your doctor will want to keep an eye on their height and weight.

  • People with diabetes, or a family history of diabetes. Dexamethasone can raise blood sugar levels and long-term use can sometimes cause diabetes or make diabetes more difficult to control.

  • People with a stomach ulcer. Dexamethasone can sometimes cause or worsen peptic ulcers so you may need to take an extra medicine to help protect your gut.

  • People with a personal or family history of psychiatric illness, including depression, bipolar disorder or schizophrenia. Dexamethasone can sometimes cause or aggravate mental health problems like these when you first start treatment, or more rarely when stopping treatment. It's important to talk to your doctor straight away if you experience any change in your mood or behaviour, for example feeling confused, irritable, anxious or depressed, or if you have hallucinations or suicidal thoughts.

  • People with or at risk of osteoporosis, including women who have passed the menopause. Steroids like dexamethasone can sometimes cause weakening or thinning of the bones.

  • People with kidney or liver problems.

  • People with heart failure or who have recently had a heart attack.

  • People with high blood pressure (hypertension).

  • People with cataracts, glaucoma, or a family history of glaucoma. Dexamethasone can cause or worsen these eye conditions.

  • People with an infection, particularly people with herpes simplex virus infection of the eye or who have had tuberculosis (TB) in the past.

  • People with inflammatory bowel disease such as ulcerative colitis or diverticulitis.

  • People at risk of getting a blood clot in a blood vessel (thromboembolism, eg DVT).

  • People with an underactive thyroid gland (hypothyroidism).

  • People who suffer from epilepsy.

  • People who have previously experienced muscle disorders (myopathy) caused by steroids, or who have myasthenia gravis or Duchenne's muscular dystrophy.

  • People with a low level of potassium in their blood (hypokalaemia). Dexamethasone can make this level drop lower.

Key points to know about dexamethasone

✔️ Reduce treatment gradually

It's important that you don't stop taking dexamethasone suddenly if you've been taking it every day for more than three weeks (sometimes less - your doctor will advise). Long-term use of dexamethasone can stop your adrenal glands producing natural corticosteroids (this is called adrenal suppression), which means that your body becomes temporarily reliant on the medicine. This can also happen after repeated joint injections. When it's time to stop treatment your dose should be reduced gradually, to allow your adrenal glands to start producing enough natural steroids again. Always follow the instructions given by your doctor or pharmacist.

✔️ Show your blue steroid card

If you need to take dexamethasone for more than three weeks you will be given a blue steroid card that contains details about your treatment. Read it and carry it with you at all times. Show it to anyone who treats you for example doctor, nurse, pharmacist or dentist because the effects that corticosteroids have on the body may affect other medical treatment you may be given. If you have an accident the card contains information that could save your life. You should also show your steroid card to anyone who treats you for at least a year after you stop treatment with steroids.

✔️ See your doctor if you feel unwell

Long courses of dexamethasone may increase your susceptibility to infections and can also mask the symptoms of infections, making you think they are less serious than they are. So it's important to see your doctor if you get any signs of infection while you're taking dexamethasone.

✔️ Dexamethasone and chickenpox, shingles and measles warning

If you've never had chickenpox you should avoid contact with people who have chickenpox or shingles while you're taking dexamethasone. You should also avoid contact with people who have measles. If you're exposed to these diseases either during treatment, or in the three months after stopping treatment, you should consult your doctor urgently. This is very important as these diseases can be life-threatening in people taking long courses of corticosteroids.

✔️ Dexamethasone and mental health

Corticosteroid treatment, especially with high doses, can sometimes cause changes in your mood and behaviour when you first start treatment and some people may experience confusion, irritability, nightmares, difficulty sleeping, mood changes or depression, or suffer from delusions and suicidal thoughts. In a few cases these problems have happened when stopping treatment. It's important to let your doctor know if you notice any change in your mood or behaviour, particularly if you begin to feel depressed, or have any disturbing thoughts or feelings. Most of these problems go away if the dose is lowered or the medicine is stopped. However if problems do happen they might need treatment.

✔️ Alcohol and dexamethasone

It's usually fine to drink alcohol in moderation during treatment with dexamethasone.

✔️ Dexamethasone and driving

Taking dexamethasone is unlikely to affect your ability to drive, but if you do feel dizzy or sleepy after taking it then wait for this to wear off before driving.

How should dexamethasone be taken?

The dexamethasone dose prescribed by your doctor depends on the condition being treated and will vary from person to person. It's important that you always follow the instructions given by your doctor or pharmacist and ask them for advice if you're not sure about anything.

You may be asked to take dexamethasone as a single dose, as a short course (for example every day for a few days) or on a regular basis for longer periods of time.

If you're prescribed a course of treatment you usually take dexamethasone by mouth once a day, in the morning after breakfast, but always follow your doctor's instructions. Sometimes your doctor might want you to take a dose more frequently than this.

If you're having an overnight dexamethasone suppression test for Cushing's, you usually take a single dose the night before your test, but always follow your doctor's instructions.

Dexamethasone should preferably be taken with food or just after eating. This helps avoid the medicine irritating your stomach.

Missed dose: If you forget to take a dose at your usual time, take it with food as soon as you remember. Take your next dose as usual. If you don't remember a missed dose until your next dose is due, leave out the missed dose. Don't take a double dose to make up for a missed dose. If you miss more than one dose you should contact your doctor for advice.

When do I stop taking dexamethasone?

Make sure you keep taking dexamethasone until your doctor has told you to stop. Remember that if you've been taking dexamethasone for longer than three weeks you shouldn't stop suddenly - your dose needs to be gradually reduced.

Your doctor may also want you to stop treatment gradually if:

  • you've taken a high dose for more than a week

  • you've taken a short course within a year of stopping prolonged steroid treatment

  • you've recently taken repeated courses of steroids

  • you have been repeatedly taking doses in the evening

  • you had problems with your adrenal glands before treatment was started.

Is dexamethasone safe to use during pregnancy?

The benefits of using dexamethasone during pregnancy will usually outweigh any risks.

If taken for long periods or repeatedly during pregnancy, corticosteroids have the potential to slow growth in the developing baby. Short-term use is not associated with this. Steroid medicines taken by the mother may also cause the baby to make less of its own steroid hormones after birth, though this usually resolves on its own and rarely causes any problems. If your doctor thinks you need to take dexamethasone during your pregnancy, it's because any risks associated with taking the medicine are lower than the risks of not treating your condition. If you're worried then you should discuss this with your doctor, midwife or pharmacist.

If you think you could be pregnant while you're taking dexamethasone you should ask your doctor for advice. It's important that you don't suddenly stop taking it unless your doctor tells you to.

Is dexamethasone safe to use during breastfeeding?

The benefits of using dexamethasone while breastfeeding will usually outweigh any risks.

Dexamethasone does pass into breast milk, but low doses taken by the mother are unlikely to significantly affect a nursing baby. If you're taking a high dose for long periods of time your doctor might want to monitor your baby, because the medicine could potentially cause the baby to make less of its own steroid hormones. Ask your doctor for advice.

Can I take other medicines with dexamethasone?

You should check with your pharmacist before taking any new medicines while you are taking dexamethasone, to make sure that the combination is safe.

Dexamethasone with painkillers

It is safe to take paracetamol, co-codamol and codeine with dexamethasone.

Taking of anti-inflammatory painkillers (NSAIDs) like aspirin, ibuprofen or naproxen painkiller with dexamethasone may increase the risk of side effects on the gut, such as stomach ulceration and bleeding. Avoid taking these painkillers if you're taking dexamethasone, unless they've been prescribed by your doctor.

Dexamethasone with antacids

Avoid taking antacids within two hours of taking dexamethasone because they could reduce its absorption from the gut and so make it less effective.

Dexamethasone with medicines for diabetes

Dexamethasone may increase blood sugar levels and so may oppose the blood sugar lowering effects of antidiabetic medicines. People with diabetes may need an increase in their dose of insulin or antidiabetic tablets.

Dexamethasone with anticoagulants

Dexamethasone may enhance the anti-blood-clotting effect of anticoagulant medicines such as warfarin. If you're taking warfarin with dexamethasone your blood clotting time (INR) should be regularly monitored, particularly after starting or stopping treatment with dexamethasone and after any dose changes.

Dexamethasone with medicines that lower potassium levels

The level of potassium in your blood is more likely to fall too low if you take dexamethasone with other medicines that can lower the amount of potassium in your blood, such as:

  • acetazolamide

  • aminophylline

  • amphotericin

  • beta 2 agonists, such as salbutamol or terbutaline

  • corticosteroids, such as hydrocortisone or prednisolone

  • Diuretics, such as bendroflumethazide or furosemide

  • reboxetine

  • stimulant laxatives such as senna

  • theophylline.

Other medicine interactions with dexamethasone

Dexamethasone may make the following medicines less effective:

  • axitinib

  • cabozantinib

  • caspofungin

  • daclatasvir

  • indinavir

  • isoniazid

  • lopinavir

  • praziquantel

  • rilpivirine

  • telaprevir

  • saquinavir

  • simeprevir.

You are more likely to have problems with your liver if you take dexamethasone with high-dose methotrexate.

The following medicines may increase the removal of dexamethasone from the body, thus reducing its effects. You may need a larger dose of dexamethasone if you are also taking any of these medicines:

  • barbituates, such as amobarbital, phenobarbital

  • carbamazepine

  • fosphenytoin

  • phenytoin

  • primidone

  • rifabutin

  • rifampicin.

The following medicines may reduce the removal of dexamethasone from the body and so may increase the risk of its side effects:

  • aprepitant

  • ciclosporin (dexamethasone may also increase the blood level and risk of side effects of ciclosporin)

  • fosaprepitant

  • itraconazole

  • ketoconazole

  • macrolide-type antibiotics, such as erythromycin

  • protease inhibitors for example ritonavir.

Can I be given vaccines while taking dexamethasone?

Dexamethasone may weaken your immune system, which means that vaccines may be less effective if given during treatment, because your body won't produce sufficient antibodies in response to the vaccine.

Live vaccines shouldn't be given to people taking dexamethasone because they may cause serious infections. Live vaccines include: measles, mumps, rubella (MMR), BCG, chickenpox, oral typhoid, yellow fever and the nasal spray flu vaccine for children. You shouldn't be given a live vaccine until at least three months after finishing a course of dexamethasone.

Dexamethasone and COVID-19

A recent study called the RECOVERY trial has shown that using dexamethasone in patients with SARS-CoV-2 infection (usually called COVID-19) significantly reduced death rates from all causes. This has led to it now becoming commonly used in patients hospitalised with COVID-19 who are severely or critically ill.

For patients who were on oxygen, but not mechanical ventilation at the start of the study, on average for every 100 patients who were given dexamethasone, 3 did not die because they were given it, 74 did not die whether they had it or not, and 23 died even though they had been given it.

For patients who were on a ventilator at the start of the study, on average for every 100 patients who were given dexamethasone, 12 did not die because they were given it, 59 did not die whether they had it or not, and 29 died even though they had been given it.

For patients who did not need oxygen or ventilation at the start of the study, dexamethasone was not shown to reduce the risk of dying.

The current guidance is therefore that it should be offered to people with COVID-19 and any of the following;

  • Acute respiratory distress syndrome (ARDS)

  • Sepsis or septic shock

  • Other conditions that would normally need life-sustaining treatment such as mechanical ventilation

  • Severe respiratory distress

  • An oxygen saturation of less than 90% on room air

  • A breathing rate of more than 30 breaths/minute in adults and children over the age of 5.

Dexamethasone should not normally be used in people with COVID-19 that is not severe or critical, because of the possibility of harm to such people. It is given by mouth or intravenously for 7-10 days, but treatment should stop if the person is discharged from hospital before the 10 day course is completed.

Last updated: 04.11.2020

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