Dexamethasone (Decadron) - Uses, Side Effects, and More

What are the most common side effects of dexamethasone?

The most common side effects of dexamethasone are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

• Fluid retention (see below)
• Increased blood sugar (see below)
• Increased blood pressure (see below)
• Mood and behavior changes (see below)
• Weight gain or increased appetite

There may be other side effects of dexamethasone that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of dexamethasone?

While less common, the most serious side effects of dexamethasone are described below, along with what to do if they happen.

Severe Allergic Reactions. Dexamethasone may cause allergic reactions, which can be serious. Stop taking dexamethasone and get help right away if you have any of the following symptoms of a serious allergic reaction.

• Breathing problems or wheezing
• Racing heart
• Fever or general ill feeling
• Swollen lymph nodes
• Swelling of the face, lips, mouth, tongue, or throat
• Trouble swallowing or throat tightness
• Itching, skin rash, or pale red bumps on the skin called hives
• Nausea or vomiting
• Dizziness, feeling lightheaded, or fainting
• Stomach cramps
• Joint pain

Reduced Adrenal Function. Long-term use of dexamethasone may cause your body’s adrenal glands to stop making as much cortisol (the stress hormone). This is known as adrenal insufficiency. Adrenal insufficiency can get worse if your body is under stress because of fever, surgery, or trauma. Tell your healthcare provider if you have any of the following symptoms of adrenal insufficiency.

• Nausea and vomiting
• Weakness, tiredness, or lack of energy
• Low blood pressure

Infections. Dexamethasone can cause your immune system to not work as well, which can increase your risk of infections, including serious infections. Call your healthcare provider right away if you have an infection or any of the following symptoms.

• Burning or stinging when you pee 
• Cough or coughing up blood
• Fever, sweats, chills, or muscle aches
• Shortness of breath
• Diarrhea or stomach pain
• Weight loss

Reactivated Infections. Some types of microbes that cause infections (such as bacteria or viruses) can remain in the body after you recover from that infection. When a microbe stays in the body but does not cause an infection, it is called a “latent” microbe. Dexamethasone may increase your risk of a latent microbe becoming active again, causing an infection. Before you start treatment with dexamethasone, tell your healthcare provider if you have ever had tuberculosis (TB), hepatitis B, or any other serious infections.

Cushing’s Syndrome. Rarely, taking dexamethasone for a long time may increase your risk for Cushing’s syndrome. Cushing’s syndrome is a condition that happens when your body is exposed to too much cortisol (the stress hormone). The risk may be higher in children. Stop taking dexamethasone and call your healthcare provider if you have any of the following symptoms of Cushing’s syndrome.

• A rounded, rosy color of the face
• Weight gain, especially in the upper body
• A fat buildup in the upper back or base of the neck
• Thinning skin that bruises easily
• Feeling very weak or tired
• Depression or anxiety
• High blood sugar
• High blood pressure
• Sleep problems

High Blood Sugar. Dexamethasone may increase your blood sugar levels. Talk to your healthcare provider about how to maintain healthy blood sugar levels. Keep all appointments with your healthcare provider to check your blood work. Call your healthcare provider if you have the following symptoms of high blood sugar.

• Thirsty more than usual
• Peeing more than usual
• Increase in hunger
• Tiredness
• Feeling sick to your stomach
• Confusion
• Your breath smelling fruity

Vision Problems. Dexamethasone may cause cataracts and glaucoma, which can lead to blindness. Tell your healthcare provider right away if you have any of the following symptoms.

• Cloudy or foggy vision
• Nearsightedness
• Changes in how you see colors
• Problems with glare (such as traffic lights when driving at night)
• Loss of vision
• Eye pain or redness
• Severe headache or vomiting
• Seeing bright, colorful circles around lights (vision halos)

Fluid Retention (Edema). Dexamethasone can cause fluid retention, also called edema. Fluid retention can cause serious issues in people with certain conditions, such as heart failure or kidney problems. Call your healthcare provider right away if you have any of the following symptoms. 

• Chest pain
• Irregular heartbeat
• Shortness of breath
• Stretched or shiny skin
• Swollen body parts, such as the belly or ankles

Increased Blood Pressure (Hypertension). Dexamethasone may increase your blood pressure or make it worse if you have a history of high blood pressure. Call your healthcare provider if your blood pressure increases while taking this medicine.

If you measure your blood pressure and the top number (systolic) is 180 mm Hg or higher or the bottom number (diastolic) is 120 mm Hg or higher, get medical attention right away. Increases in blood pressure may not be noticeable, but look out for and tell your healthcare provider right away if you have any of the following symptoms of severely high blood pressure.

• Sudden severe headache
• Chest pain
• Dizziness or confusion
• Trouble breathing
• Nausea or vomiting
• Blurry or other changes to vision
• Anxiety
• Buzzing in the ears
• Nosebleed
• Feeling of skipped heartbeats

Weak Bones. Taking dexamethasone for a long time may cause your bones to become weaker, leading to reduced bone density (osteopenia). It may also cause a more serious condition called osteoporosis, which can cause your bones to break (fracture) more easily. Tell your healthcare provider if you break a bone, and get a bone mineral density test if one is ordered for you.  

Muscle Problems. Dexamethasone may cause muscle problems, including muscle pain, weakness, and tenderness called myopathy. Stop taking dexamethasone and get help right away if you have any of the following symptoms of myopathy.

• Muscle pain, stiffness, or cramps
• Muscle spasms
• Low energy levels or feeling easily tired, especially with activity

Slowed Growth in Children. Dexamethasone, when taken by children, can slow down growth. The risk may be higher in children who take it for a long time. Tell your child’s healthcare provider if you have concerns about your child’s growth.  

Mood Changes. Dexamethasone may cause mood swings, personality changes, intense excitement, or depression. Call your healthcare provider right away if you or a caregiver notice any new or worsening behavior.