> Western Medicines > Dexamethasone

What is Dexamethasone for?

Dexamethasone belongs to a class of medications called glucocorticoids or steroid hormones. It mainly works by reducing inflammation and has a wide range of uses, including but not limited to: 

  • Suppression of inflammation and allergy
  • Eye inflammation
  • Joint inflammation
  • Treatment of croup
  • Prevention of nausea and vomiting associated with chemotherapy

In a recent clinical trial done by the University of Oxford, Dexamethasone was found to lower the death risk in COVID-19 patients on ventilators and on oxygen, compared with those receiving usual medical care. In the study, patients were given 6 mg once daily (either by mouth or by intravenous injection) for 10 days. However, Dexamethasone does not appear to improve milder symptoms and is not effective in patients without the need for mechanical ventilation. 

How to use it?

The adult doses of Dexamethasone for different uses by different routes of administration are listed below:


For suppression of inflammation and allergy

0.5-10 mg daily.


For eye inflammation

Topically as 0.1% suspension
Apply 1-2 drops to the affected eye(s) 4-6 times daily. The dose may increase up to every hour in severe cases.


Topically as 0.05% ointment
Apply 0.5-1 inch into the affected conjunctival sac(s) up to 4 times daily and reduce to once daily if the conditions improve.


For joint inflammation

Topically to the joint(s)
0.3-3.3 mg. The dose can be repeated every 3-21 days according to your response. The dose given depends on the product used.

What are the side effects of Dexamethasone?

When Dexamethasone is taken by mouth for long-term use, it can have side effects such as anxiety, cataracts, cognitive impairment, fat redistribution (moon face and buffalo hump), fluid retention, gastrointestinal discomfort, headache, impaired wound healing, high blood pressure, increased risk of infection, menstrual cycle irregularities, and osteoporosis.

Who should not take Dexamethasone?

  • People who are allergic to Dexamethasone or any other components of the formulation
  • Patients with systemic fungal infections

Pharmacist Tips:

  • You may also need to increase your dietary intake of Potassium, Calcium, Phosphorus, Folate, Vitamin C, and Vitamin D.
  • Report signs of new or worsening infections to your doctor or pharmacist.
  • After long-term use of this drug, contact your doctor or pharmacist if you notice fatigue, weight gain, or thinning of the skin that bruises easily.
  • If you are using the eye ointment, your vision can be blurred for a few minutes. You should shake the suspension well before use to ensure accurate dosing.

Common dosing schedule:

  • Oral Dexamethasone can be taken with or without meals. Meals can reduce gastrointestinal upset.
  • Do not discontinue oral Dexamethasone abruptly. Discuss with your healthcare provider before stopping.

This schedule is for reference only, adjustments may be made according to individual needs.


Some common medications Dexamethasone may interact:

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Dexamethasone in Hong Kong?

In Hong Kong, Dexamethasone is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.


For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Dexamethasone in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.

Brands in Hong Kong
Available dosage
  • 2mg/ml / 5mg/ml (Injections)
  • 0.5mg / 4mg (Tablets)
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