You should not use dexamethasone if you have a fungal infection anywhere in your body.
Tell your doctor about all your medical conditions, and all the medicines you are using. There are many other diseases that can be affected by steroid use, and many other medicines that can interact with steroids.
Your dosage may change if you have any unusual stress such as a serious illness, fever or infection, or if you have surgery or a medical emergency. Tell your doctor about any such situation that affects you during treatment.
Dexamethasone can weaken your immune system, making it easier for you to get an infection or worsening an infection you already have or have recently had. Tell your doctor about any illness or infection you have had within the past several weeks.
Call your doctor for preventive treatment if you are exposed to chicken pox or measles. These conditions can be serious or even fatal in people who are using steroid medication.
All vaccines may not work as well while you are taking a steroid. Do not receive a "live" vaccine while you are taking this medicine.
Do not stop using dexamethasone suddenly, or you could have unpleasant withdrawal symptoms. Talk to your doctor about how to avoid withdrawal symptoms when stopping the medication.