Dexamethasone is a powerful corticosteroid used to treat inflammation, autoimmune conditions, and severe allergic reactions. It’s also been a lifeline in critical care, especially during the COVID-19 pandemic. But like all strong medications, it doesn’t come without risks. Knowing how it works, when it helps, and what to watch out for can make all the difference between recovery and complications.

What Dexamethasone Does in the Body

Dexamethasone is a synthetic version of cortisol, the hormone your adrenal glands naturally produce to manage stress and inflammation. It’s about 25 times more potent than cortisol, which means even small doses can have big effects. Once taken, it travels through your bloodstream and binds to receptors in cells that control immune responses and inflammation.

This makes it useful in situations where your body’s immune system is overreacting - like in rheumatoid arthritis, lupus, or severe asthma. It doesn’t cure these conditions, but it shuts down the swelling and pain that make them unbearable. In hospitals, it’s often given to patients with severe respiratory infections to reduce lung inflammation and improve oxygen flow.

Common Uses of Dexamethasone

Dexamethasone isn’t just for one thing. Doctors use it in many different ways:

• Severe allergic reactions - including anaphylaxis when epinephrine alone isn’t enough.
• Inflammatory diseases - like multiple sclerosis flare-ups, Crohn’s disease, and ulcerative colitis.
• Cancer treatment support - to reduce nausea from chemotherapy and shrink tumors in certain blood cancers like multiple myeloma.
• Brain swelling - after head injuries or brain tumors, it helps reduce pressure inside the skull.
• Preterm labor - given to pregnant women at risk of early delivery to help the baby’s lungs mature faster.
• COVID-19 - in hospitalized patients needing oxygen or ventilation, it reduced death rates by up to one-third in major trials like the RECOVERY study in the UK.

These aren’t off-label uses - they’re backed by decades of clinical evidence. But that doesn’t mean it’s safe to take without supervision.

How Dexamethasone Is Taken

Dexamethasone comes in several forms: tablets, liquid, injections, and even eye drops. The dose depends entirely on the condition being treated.

For example:

• For inflammation: 0.75 mg to 9 mg per day, usually split into one or two doses.
• For severe asthma or allergic reactions: a single 10 mg dose, sometimes followed by a tapering schedule.
• For COVID-19 in hospitals: 6 mg once daily for up to 10 days, often given as a tablet or IV.
• For children with brain tumors: doses are calculated by weight - typically 0.15 mg per kg per day.

Never adjust your dose on your own. Even small changes can trigger withdrawal symptoms or make your condition worse. If you’ve been on it for more than a week, your doctor will likely tell you to slowly reduce the dose instead of stopping cold turkey.

Common Side Effects

Most people tolerate dexamethasone well for short periods. But even a few days of use can cause noticeable changes:

• Increased appetite and weight gain - especially around the face and abdomen. This is often called "moon face" or "buffalo hump."
• Mood swings - feeling anxious, irritable, or even depressed. Some people report sudden euphoria or insomnia.
• Fluid retention - swollen ankles, puffiness, or high blood pressure.
• Higher blood sugar - especially risky for people with diabetes. Some need to adjust their insulin or oral meds while taking it.
• Stomach upset - nausea, indigestion, or even ulcers if taken long-term without a stomach protector.

These side effects usually fade once you stop the medication. But if you’re taking it for more than a few weeks, they can become more serious.

Serious Risks With Long-Term Use

If you’re on dexamethasone for months or years - say, for chronic autoimmune disease - the risks multiply:

• Bone thinning (osteoporosis) - your body breaks down bone faster than it rebuilds it. Doctors often prescribe calcium, vitamin D, or bisphosphonates to protect your bones.
• Increased infection risk - because it suppresses your immune system, you’re more vulnerable to pneumonia, urinary tract infections, or even reactivated viruses like shingles.
• Adrenal suppression - your body stops making its own cortisol. If you suddenly stop the drug, you could go into adrenal crisis - low blood pressure, vomiting, confusion, even coma.
• Cataracts and glaucoma - long-term use raises eye pressure and clouding of the lens. Regular eye checks are recommended.
• Muscle weakness - especially in the thighs and shoulders. This can make walking or climbing stairs difficult.

These aren’t rare. In fact, studies show that over 50% of patients on daily steroids for more than a year develop at least one major complication. That’s why doctors try to use the lowest dose for the shortest time possible.

Who Should Avoid Dexamethasone

Some people shouldn’t take it at all - or need extra monitoring:

• People with active infections - like tuberculosis, fungal infections, or untreated herpes. Steroids can make them worse.
• Those with peptic ulcers - dexamethasone can cause bleeding or perforation.
• Diabetics - blood sugar control becomes much harder. Close monitoring is essential.
• Pregnant women - unless absolutely necessary. It can cross the placenta and affect fetal growth.
• People with mental health conditions - history of psychosis or severe depression? Dexamethasone can trigger a relapse.

If you’re unsure whether it’s safe for you, talk to your doctor. Bring a full list of everything you take - including herbs, supplements, and over-the-counter painkillers. Some drugs, like NSAIDs or blood thinners, can interact dangerously with dexamethasone.

What to Do If You Miss a Dose

If you forget a tablet, take it as soon as you remember - unless it’s close to your next dose. Never double up. Missing one dose won’t hurt, but skipping multiple doses or stopping suddenly can cause withdrawal symptoms:

• Extreme fatigue
• Joint pain
• Nausea and vomiting
• Dizziness or low blood pressure
• Low blood sugar

If you’ve been on dexamethasone for more than a week and need to stop, your doctor will give you a tapering plan. This might mean cutting the dose by 25% every few days until you’re off it completely. Skipping this step is dangerous.

When to Call Your Doctor

Call your doctor right away if you notice any of these:

• Sudden vision changes
• Severe stomach pain or black, tarry stools
• Fever, chills, or cough that won’t go away
• Swelling in your legs or difficulty breathing
• Thoughts of self-harm or extreme mood changes
• Signs of an allergic reaction - rash, swelling of the face or throat, trouble breathing

These aren’t common, but they’re serious. Don’t wait. Get help fast.

Dexamethasone vs. Other Steroids

There are many corticosteroids - prednisone, hydrocortisone, methylprednisolone. How does dexamethasone compare?

Dexamethasone’s long half-life means it stays active in your body for days. That’s good for one-dose treatments - like for brain swelling or post-surgery inflammation. But it’s also why side effects hang around longer. For long-term use, doctors often switch to shorter-acting steroids like prednisone to make tapering easier.

What Happens After You Stop

Once you finish dexamethasone, your body needs time to wake up its own cortisol production. This can take weeks or even months, depending on how long you were on it.

During this time, you might feel tired, weak, or moody. That’s normal. Don’t mistake it for your original condition coming back. Your doctor might recommend:

• Gradual return to normal activity
• Monitoring for signs of adrenal insufficiency
• Wearing a medical alert bracelet if you’ve been on steroids for over a year

And if you ever need emergency surgery or a serious illness in the future - even years later - tell every doctor you’ve taken dexamethasone. You might need a temporary steroid boost during stress.

Final Thoughts

Dexamethasone is one of the most powerful tools in modern medicine. It’s saved lives in ICU wards, helped children breathe during asthma attacks, and given relief to people with chronic pain. But it’s not a gentle drug. It changes how your body works - and that comes with consequences.

The key is using it wisely: the right dose, for the right reason, for the shortest time. Never take it because someone else said it helped them. Never stop it suddenly. Always talk to your doctor about what you’re feeling - even if it seems minor.

If you’ve been prescribed dexamethasone, you’re not alone. Millions use it safely every year. But the line between healing and harm is thin. Stay informed. Stay alert. And never underestimate the power - or the risk - of this medicine.