Dexamethasone is a generic drug that’s prescribed for treating many conditions, including multiple sclerosis and allergic reactions. As with other drugs, dexamethasone can cause side effects, such as unintentional weight gain and insomnia.

Dexamethasone oral tablet is available as the brand-name drug Hemady, but only in a 20 milligram (mg) strength. Other strengths of dexamethasone oral tablet aren’t available in a brand-name version.

Dexamethasone also comes in forms that are injectable and topical, but this article does not cover them.

Read on to learn about potential common, mild, and serious side effects of dexamethasone. For a general overview, including details about its uses, see this article on dexamethasone oral tablet.

Dexamethasone oral tablet can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the most common side effects of dexamethasone reported:

Mild side effects can occur with dexamethasone use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to the drug’s prescribing information.

Mild side effects that have been reported with dexamethasone include:

  • increased or decreased appetite
  • headache
  • indigestion
  • insomnia
  • fluid retention and swelling (edema)
  • acne
  • nausea and vomiting
  • thinning hair on your scalp
  • unintentional weight gain (see “Dexamethasone: Side effect specifics”)

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking dexamethasone and want to tell the FDA about it, visit MedWatch.

Dexamethasone may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to the prescribing information for dexamethasone oral tablet.

If you develop serious side effects while taking dexamethasone, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • adrenal insufficiency, which may include symptoms such as:
    • persistent fatigue
    • appetite loss
  • digestive side effects, including perforations (holes) in your digestive tract, which may include symptoms such as:
    • severe pain and tenderness in your abdomen
    • nausea and vomiting
  • eye-related side effects, including glaucoma and cataracts, which may include symptoms such as:
  • heart-related side effects, including irregular heart rhythm and heart failure, which may cause symptoms such as:
  • high blood sugar and type 2 diabetes, which may include symptoms such as:
    • increased thirst
    • urinating more frequently
  • increased pressure in your brain (intracranial hypertension), which may include symptoms such as:
    • severe, persistent headache
    • blind spots in your vision
  • liver damage, which may include symptoms such as:
    • nausea and vomiting
    • jaundice (yellowish coloration of your eyes or skin)
  • low level of potassium in the blood, which may include symptoms such as:
    • muscle weakness
    • cramping during exercise
  • myopathy, which may include symptoms such as:
    • pain, spasms, or cramps in your muscles
    • exercise intolerance
  • high blood pressure, which typically doesn’t cause symptoms but raises your risk of heart attack or stroke
  • increased risk of infection, including serious infections
  • osteoporosis, which may not cause symptoms but increases your risk of bone fractures or breaks
  • mental health side effects (see “Dexamethasone: Side effect specifics”)
ALLERGIC REACTION

For some people, Dexamethasone oral tablet can cause an allergic reaction.

In general, symptoms of an allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to dexamethasone oral tablet, your doctor may recommend taking a different medication instead.

Dexamethasone may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Can a single dose of dexamethasone cause side effects?

Yes, taking a single dose of dexamethasone can cause side effects. But you may have a lower risk for certain side effects.

For example, developing myopathy (muscle disease) after a single dose of dexamethasone is unlikely. This rare but serious side effect can happen with long-term dexamethasone use, though.

Taking a single dose of dexamethasone may cause a temporary high blood sugar level. But it won’t cause type 2 diabetes, which is a possible side effect with long-term dexamethasone treatment.

If you have questions about your risk of side effects based on how long you’ll take dexamethasone, ask your doctor or pharmacist.

How long do side effects of dexamethasone last? Could I still feel dexamethasone side effects after stopping treatment?

It depends. Often, the side effects of dexamethasone are temporary. Mild side effects may last a few hours or days and go away on their own. But there are rare cases where a mild side effect such as nausea or vomiting persists.

Dexamethasone can also cause long-term side effects. Long-term side effects refer to side effects that persist throughout treatment. It can also refer to the side effects that don’t go away, even after stopping treatment.

Long-term side effects of dexamethasone reported include:

  • adrenal insufficiency, which may go away after you stop taking dexamethasone
  • heart failure, which may persist even after you stop treatment with dexamethasone but can be managed using medications
  • myopathy, which may go away after you stop treatment with dexamethasone but this can take weeks or even years in some cases
  • osteoporosis, which may persist after stopping treatment but can be managed with medications

This is not a complete list of all long-term side effects of dexamethasone. Your doctor or pharmacist can answer any additional questions you may have about dexamethasone and its long-term side effects.

Learn more about some of the side effects that dexamethasone may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for dexamethasone oral tablet.

Weight gain

Unintentional weight gain is a possible side effect of dexamethasone and other corticosteroids. It’s not clear how often this side effect happened in dexamethasone clinical trials. However, this side effect is more likely with long-term versus short-term dexamethasone treatment.

Other side effects of dexamethasone can contribute to weight gain. For example, increased appetite, fluid retention, and swelling (edema) are other possible side effects of dexamethasone. An increased appetite can cause you to consume more calories than usual. And fluid retention means your body retains more water than usual. Both of these effects can cause unintentional weight gain.

What you can do

Talk with your doctor if you have concerns about your weight while taking dexamethasone. They can discuss strategies to maintain a moderate weight.

Mental health side effects

As with other corticosteroid medications, dexamethasone can cause mental health side effects. It’s not clear from the dexamethasone prescribing information how often these side effects occurred in clinical trials. While mental health side effects can happen with short-term dexamethasone use, they’re more likely with long-term use.

Mental health side effects of dexamethasone may include:

  • depression, which may cause symptoms such as:
    • losing interest in hobbies and activities you typically enjoy
    • difficulty concentrating and making decisions
  • sudden shifts in mood
  • personality changes, such as acting agitated or aggressive
  • psychosis, which may cause symptoms such as:
    • a sudden decline in personal hygiene and self-care
    • feeling suspicious or uneasy around others

If you have an existing mental health condition, taking dexamethasone could worsen your symptoms. Having a mental health condition can also raise the risk of developing new mental health side effects from taking the medication.

What you can do

Before you start taking dexamethasone, be sure to tell your doctor about any condition you have affecting your mental health. Your doctor may want to ensure it’s properly treated before prescribing dexamethasone.

While taking dexamethasone oral tablet, pay close attention to your thinking, moods, and emotions. Let your doctor know right away if you notice symptoms of mental health side effects. They can recommend an appropriate treatment based on your symptoms.

Before taking dexamethasone oral tablet, discuss your health history with your doctor. Dexamethasone may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.