© gilaxiaDexamethasone used for diseases of the adrenal glands, croup. given as an injection for rheumatoid arthritis, tennis elbow and dexamethasone suppression test.
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 (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 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.
It 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.
Who should be careful using it?
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 info to know about dexamethasone
?? 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.
?? 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.
?? 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.
?? 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.
?? 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.
?? It's usually fine to drink alcohol in moderation during treatment with dexamethasone.
?? 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.
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Last updated: 26.09.2019