Unfortunately dexamethasone (and his little brothers prednisolone, methylprednisolone, and prednisone) can cause many serious side effects. Most are temporary and will go away when the medication is stopped. Others can be permanent. In most cases, the side effects are proportional to the magnitude of the dosage and the length of time it is prescribed. Here are some of the most common side effects.
Infections: Steroids block the response to white blood cells to infection. The white blood cell count often rises in persons on steroids because the cells are not able to leave the blood and enter infected tissue. Patients on steroids are at high risk for infection. Often prophylactic antibiotics, antivirals, and antifungals if steroid therapy will be long term. Richard takes doxycycline, acyclovir, and fluconazole every day.
Fluid Retention and Electrolyte Disturbances: Steroids cause the body to retain sodium which in turn causes fluid retention and high blood pressure. Potassium can be excreted excessively. Persons with cardiac or renal disease need to be closely monitored.
Skin Problems: Acne and other types of rashes may develop. Wounds heal slower and many notice increased sweating.
Endocrine Effects: Steroids raise blood sugar. Diabetics need to carefully monitor their blood sugar when they take steroids. Most will need more medication to control blood sugar. Others may need to use insulin temporarily. Richard developed diabetes early in his treatment with dex. He took oral medication for awhile, but after his kidney problems during the last transplant, he now only uses insulin.
Gastrointestinal Effects; Steroids increase the risk perforation of the GI tract, especially if there is pre-existing peptic ulcer disease or diverticulitis. Steroids also increase appetite and this, along with fluid retention, causes weight gain.
Ophthalmologic effects: cataracts, increased intraocular pressure, generalized changes in vision
Psychiatric Effects: insomnia, mood swings, irritability, personality changes, and severe depression. Emotional instability or psychotic tendancies can worsen. Frank psychosis is possible.
Other side effects: hoarseness or other changes in the voice, muscle weakness and generalized muscle aching, osteoporosis, joint destruction