Dexamethasone Oral Solution 0.5mg Per 5 mL, Bottle 250 mL (Rx)Dexamethasone Oral Solution 0. 5mg Per 5 mL is a corticosteroid that is used to treat various conditions such as allergic reactions, skin conditions, asthma, and arthritis. Dexamethasone Oral Solution 0. 5mg Per 5 mL is also used to treat cancer. Dexamethasone Oral Solution 0. 5mg Per 5 mL is a very effective medication that works by suppressing the immune system. Dexamethasone Oral Solution 0. 5mg Per 5 mL is available as a prescription medication.