Dexamethasone – Dosage, Overdose, and Interactions


Dexamethasone, or MK-125, is a corticosteroid fluorinated at position 9 used to treat endocrine, rheumatic, collagen, dermatologic, allergic, ophthalmic, gastrointestinal, respiratory, hematologic, neoplastic, edematous, and other conditions. Developed in 1957, it is structurally similar to other corticosteroids like hydrocortisone and prednisolone.

Dexamethasone was granted FDA approval on 30 October 1958. In a press release for the Randomized Evaluation of COVID-19 Therapy (RECOVERY) trial on 16 June 2020, dexamethasone was recommended for use in COVID-19 patients with severe respiratory symptoms. Dexamethasone reduced deaths by approximately one third in patients requiring ventilation and by one fifth in those requiring oxygen.

Properties and characteristics of Dexamethasone

Drug class Corticosteroids
Brand Names Baycadron, Ciprodex, Decadron, Dexamethasone Intensol, Dextenza, Dioptrol, Hexadrol, Hidex 6-day Taper, Maxidex, Maxitrol, Neofordex, Ozurdex, Taperdex 12 Day Taper, Taperdex 6 Day Taper, Taperdex 7-day Taper, Tobradex, Zcort 7 Day Taper
Synonyms Dexametasona, Dexamethasone, Dexaméthasone, Dexamethasonum
Molecular Formula C22H29FO5
Molecular Weight 392.5 g/mol
IUPAC Name (8S,9R,10S,11S,13S,14S,16R,17R)-9-fluoro-11,17-dihydroxy-17-(2-hydroxyacetyl)-10,13,16-trimethyl-6,7,8,11,12,14,15,16-octahydrocyclopenta[a]phenanthren-3-one
Structural formula of main components
Pure active ingredient Dexamethasone
Appearance Odorless white to off-white crystalline powder
Melting point   262-264 °C
Solubility 89mg/L (at 25 °C)
Excretion Dexamethasone is metabolized by the liver and excreted in the urine mainly
Storage Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
Available Forms Implant, Tablet, Elixir, and Solution
Prescription Do not consume without the doctors’ advice

Why it’s used?

The dexamethasone oral tablet is used to treat conditions that cause inflammation, conditions related to immune system activity, and hormone deficiency. These conditions include:

  • Inflammation
  • Allergic reactions
  • Rheumatoid arthritis and other rheumatic diseases, including ankylosing spondylitis, psoriatic arthritis, juvenile rheumatoid arthritis, lupus, and acute gouty arthritis
  • Skin diseases, such as atopic dermatitis (eczema), pemphigus, severe erythema multiforme (Stevens-Johnson syndrome), exfoliative dermatitis, bullous dermatitis herpetiformis, severe seborrheic dermatitis, severe psoriasis, or mycosis fungoides
  • Flare-ups of intestinal diseases, such as ulcerative colitis
  • Flare-ups of multiple sclerosis or myasthenia gravis
  • Pretreatment for chemotherapy to reduce inflammation and side effects from cancer medications
  • Certain leukemias and lymphomas
  • Adrenal insufficiency (a condition where the adrenal glands don’t produce enough hormones)

What side effects can this medication cause?

Dexamethasone may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • Upset stomach
  • Stomach irritation
  • Vomiting
  • Headache
  • Dizziness
  • Insomnia
  • Restlessness
  • Depression
  • Anxiety
  • Acne
  • Increased hair growth
  • Easy bruising
  • Irregular or absent menstrual periods

If you experience any of the following symptoms, call your doctor immediately:

  • Skin rash
  • Swollen face, lower legs, or ankles
  • Vision problems
  • Cold or infection that lasts a long time
  • Muscle weakness
  • Black or tarry stool

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA)

Mechanism of action

The short-term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation.3 Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days.

Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10.

Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels.

What other drugs will affect dexamethasone?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Tell your doctor about all your current medicines. Many drugs can affect dexamethasone, especially:

  • An antibiotic or antifungal medicine;
  • Birth control pills or hormone replacement therapy;
  • Insulin or diabetes medications you take by mouth;
  • Medicine to treat dementia or Parkinson’s disease;
  • A blood thinner – warfarin, Coumadin, Jantoven; or
  • Nsaids (nonsteroidal anti-inflammatory drugs) – aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others.

This list is not complete and many other drugs may interact with dexamethasone. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Dosage for Dexamethasone

The dose of this medicine will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (solution, tablets):
    • Dose depends on medical condition:
      • Adults—At first, 0.75 to 9 milligrams (mg) per day. Your doctor may adjust your dose as needed.
      • Children—Dose is based on body weight and must be determined by your doctor. At first, 0.02 to 0.3 mg per kilogram (kg) of body weight per day, divided and taken 3 or 4 times a day. Your doctor may adjust your dose as needed.
    • For multiple myeloma:
      • Adults—20 or 40 milligrams (mg) once a day.
      • Children—Use and dose must be determined by your doctor.

Overdose of Dexamethasone

After taking dexamethasone for a long time

  • Decreased muscle mass and muscle weakness
  • Impaired wound healing
  • Decreased growth
  • Thin, fragile skin
  • Weakened bones

These are the most common side effects, but there may be others. Please report all side effects to the doctor or nurse.

Dexamethasone – Warnings and Precautions

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies: Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric: Appropriate studies have not been performed on the relationship of age to the effects of Hemady™ in the pediatric population. Safety and efficacy have not been established.

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of dexamethasone in children. However, pediatric patients are more likely to have slower growth and bone problems if dexamethasone is used for a long time. Recommended doses should not be exceeded, and the patient should be carefully monitored during therapy.

Geriatric: Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of dexamethasone in the elderly. However, elderly patients are more likely to have osteoporosis (weak bones) and age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for elderly patients receiving dexamethasone.

Breastfeeding: There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

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