BMA Concise Guide to Medicine & Drugs

Dexamethasone

Brand names Dexsol, Maxidex, Ozurdex

Used in the following combined preparations Maxitrol, Otomize, Sofradex, Tobradex, and others

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Drug group Corticosteroid

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Dexamethasone is a long-acting and potent corticosteroid drug that is prescribed to suppress inflammatory and allergic disorders, such as rheumatoid arthritis, shock, and brain swelling (as a result of injury or tumour).

It is also used in conjunction with other drugs to alleviate the nausea and vomiting associated with chemotherapy. Dexamethasone is available in different forms, including tablets, oral solution, injection, and eye and ear drops.

Low doses of dexamethasone taken for short periods rarely cause serious side effects. However, as with other corticosteroids, long-term treatment, especially with high doses, can cause significant adverse effects.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, liquid, injection, eye ointment, eye/ear drops, ear/nasal spray.

Frequency and timing of doses 1–4 x daily with food (by mouth); 1–6 hourly (eye drops); 1–4 x daily (ear drops/spray, eye ointment); 2–6 x daily (nasal spray).

Dosage range Usually 0.5–10mg daily (by mouth).

Onset of effect 1–4 days.

Duration of action Some effects may last several days.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect from light.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug Do not stop taking the drug without consulting your doctor. It may be necessary to withdraw the drug gradually.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

Indigestion is the most common adverse effect of dexamethasone. More rarely, there may also be acne and other skin changes and weight gain; discuss with your doctor if these become severe or if you experience fluid retention or mood changes. More serious adverse effects occur only with high doses taken for long periods (see Prolonged use), and these are carefully monitored during long-term treatment.

INTERACTIONS

Antidiabetic drugs Dexamethasone reduces the action of these drugs. Dosage may need to be adjusted accordingly to prevent abnormally high blood sugar.

Barbiturates, phenytoin, rifampicin, and carbamazepine These drugs may reduce the effectiveness of dexamethasone. The dosage may need to be adjusted accordingly.

Oral anticoagulant drugs Dexamethasone may increase the effects of these drugs.

Non-steroidal anti-inflammatory drugs These drugs may increase the likelihood of indigestion from dexamethasone.

Antacids These drugs may reduce the effectiveness of, and should be taken at least 2 hours apart from, dexamethasone.

Vaccines Dexamethasone can interact with some vaccines. Discuss with your doctor before having any vaccinations.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have had a peptic ulcer.

· You have glaucoma.

· You have high blood pressure.

· You have diabetes.

· You have epilepsy.

· You have had tuberculosis.

· You have suffered from depression or mental illness.

· You are taking other medicines.

Pregnancy Safety in pregnancy not established. Discuss with your doctor.

Breast-feeding Safety not established. The drug passes into the breast milk. Discuss with your doctor.

Infants and children Reduced dose necessary.

Over 60 No known problems.

Driving and hazardous work No known problems.

Alcohol Avoid. Alcohol may increase the risk of indigestion and peptic ulcer with this drug.

Surgery and general anaesthetics You must tell your doctor or anaesthetist that you are taking dexamethasone; close monitoring is required during surgery.

Infection Avoid exposure to chickenpox or shingles if you are on systemic treatment.

PROLONGED USE

Prolonged use by mouth can lead to peptic ulcers, glaucoma, fragile bones, muscle weakness, and growth retardation in children. People receiving long-term treatment are advised to carry a steroid treatment card.