Dexamethasone

Dexamethasone is a fluorinated glucocorticoid medication used to treat rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive pulmonary disease, croup, brain swelling, eye pain following eye surgery, superior vena cava syndrome, and along with antibiotics in tuberculosis. In adrenocortical insufficiency, it may be used in combination with a mineralocorticoid medication such as fludrocortisone. In preterm labor, it may be used to improve outcomes in the baby. It may be given by mouth, as an injection into a muscle, as an injection into a vein, as a topical cream or ointment for the skin or as a topical ophthalmic solution to the eye. The effects of dexamethasone are frequently seen within a day and last for about three days.
The long-term use of dexamethasone may result in thrush, bone loss, cataracts, easy bruising, or muscle weakness. It is in pregnancy category C in the United States, meaning that it should only be used when the benefits are predicted to be greater than the risks. In Australia, the oral use is category A, meaning it has been frequently used in pregnancy and not been found to cause problems to the baby. It should not be taken when breastfeeding. Dexamethasone has anti-inflammatory and immunosuppressant effects.
Dexamethasone was first synthesized in 1957 by Philip Showalter Hench and was approved for medical use in 1958. It is on the World Health Organization's List of Essential Medicines. In 2023, it was the 246th most commonly prescribed medication in the United States, with more than 1million prescriptions. It is available as a generic medication. In 2023, the combination of dexamethasone with neomycin and polymyxin B was the 260th most commonly prescribed medication in the United States, with more than 1million prescriptions; and the combination of dexamethasone with ciprofloxacin was the 283rd most commonly prescribed medication in the United States, with more than 700,000 prescriptions;

Medical uses

Anti-inflammatory

Dexamethasone is used to treat many inflammatory and autoimmune disorders, such as rheumatoid arthritis and bronchospasm. Idiopathic thrombocytopenic purpura, a decrease in numbers of platelets due to an immune problem, responds to 40 mg daily for four days; it may be administered in 14-day cycles. It is unclear whether dexamethasone in this condition is significantly better than other glucocorticoids.
It is also given in small amounts before and/or after some forms of dental surgery, such as the extraction of the wisdom teeth, an operation that often causes puffy, swollen cheeks.
Dexamethasone is commonly given as a treatment for croup in children. A single dose can reduce the swelling of the airway to improve breathing and reduce discomfort.
Dexamethasone is sometimes injected into the heel when treating plantar fasciitis or heel pain, sometimes in conjunction with triamcinolone acetonide. There is no evidence that this treatment helps in the long term, however, dexamethasone may provide short-term pain relief.
It may be useful to counteract allergic anaphylactic shock, however this is not usually recommended by clinical guidelines.
It is present in certain eye drops – particularly after eye surgery – and as a nasal spray, and certain ear drops. Dexamethasone intravitreal steroid implants have been approved by the US Food and Drug Administration to treat ocular conditions such as diabetic macular edema, central retinal vein occlusion, and uveitis. However, the evidence is poor quality relating to the treatment of uveitis, with the potential side effects being significant, and the benefits not certainly greater than standard treatment. Dexamethasone has also been used with antibiotics to treat acute endophthalmitis.
Dexamethasone is used in transvenous screw-in cardiac pacing leads to minimize the inflammatory response of the myocardium. The steroid is released into the myocardium as soon as the screw is extended and can play a significant role in minimizing the acute pacing threshold due to the reduction of inflammatory response. The typical quantity present in a lead tip is less than 1.0 mg.
Dexamethasone may be administered before antibiotics in cases of bacterial meningitis. Gram-negative bacteria — to which the causative agent of bacterial meningitis, Neisseria meningitidis, belongs — have highly immunogenic lipopolysaccharides as a component of their cell membrane and trigger a strong inflammatory response. Pre-administration of dexamethasone before the administration of antibiotics acts to reduce that response, thus reducing hearing loss and neurological damage.

Cancer

People with cancer undergoing chemotherapy are often given dexamethasone to counteract certain side effects of their antitumor treatments. Dexamethasone can increase the antiemetic effect of 5-HT₃ receptor antagonists, such as ondansetron. The exact mechanism of this interaction is not well-defined, but it has been theorized that this effect may be due to, among many other causes, inhibition of prostaglandin synthesis, anti-inflammatory effects, immunosuppressive effects, decreased release of endogenous opioids, or a combination of the aforementioned.
In brain tumors, dexamethasone is used to counteract the development of edema, which could eventually compress other brain structures. It is also given in cord compression, where a tumor is compressing the spinal cord. Evidence on the safety and efficacy of using dexamethasone to treat malignant brain tumors is not clear.
Dexamethasone is also used as a direct chemotherapeutic agent in certain hematological malignancies, especially in the treatment of multiple myeloma, in which dexamethasone is given alone or in combination with other chemotherapeutic drugs, including most commonly with thalidomide, lenalidomide, bortezomib, or a combination of doxorubicin and vincristine or bortezomib/lenalidomide/dexamethasone.

COVID-19

Dexamethasone is recommended by the National Health Service in the UK and the National Institutes of Health in the US for people with COVID-19 who need either mechanical ventilation or supplemental oxygen.
The Infectious Diseases Society of America guideline panel suggests the use of glucocorticoids for people with severe COVID-19, defined as people with SpO₂ ≤94% on room air, and those who require supplemental oxygen, mechanical ventilation, or extracorporeal membrane oxygenation. The IDSA recommends against the use of glucocorticoids for those with COVID-19 without hypoxemia requiring supplemental oxygen.
The World Health Organization recommends systemic corticosteroids rather than no systemic corticosteroids for the treatment of people with COVID-19. The WHO suggests not to use corticosteroids in the treatment of people with non-severe COVID-19.
The Oxford University RECOVERY Trial issued a press release announcing preliminary results that the drug could reduce deaths by about a third in participants on ventilators and by about a fifth in participants on oxygen; it did not benefit people who did not require respiratory support. A meta-analysis of seven clinical trials of critically ill COVID-19 participants, each treated with one of three different corticosteroids found a statistically significant reduction in death. The largest reduction was obtained with dexamethasone.
In September 2020, the European Medicines Agency endorsed the use of dexamethasone in adults and adolescents, from twelve years of age and weighing at least, who require supplemental oxygen therapy. Dexamethasone can be taken by mouth or given as an injection or infusion into a vein.
In November 2020, the Public Health Agency of Canada's Clinical Pharmacology Task Group recommended dexamethasone for hospitalized patients requiring mechanical ventilation. Although dexamethasone, and other glucocorticoids, reduce mortality in COVID-19 they have also been associated with an increased risk of secondary infections, secondary infections being a significant issue in critically ill COVID-19 patients.
The mechanism of action of dexamethasone involves suppression of late-stage interferon type I programs in severe COVID-19 patients.

Surgery

Dexamethasone is used fairly regularly, often as a single intravenous dose, during surgery to prevent postoperative nausea and vomiting, manage pain, potentially reduce the amount of pain medication required, and help reduce post-surgery hospitalisation time. The adverse effects of taking steroids after surgery on wound healing, blood sugar levels, and in diabetics are not completely understood; however, dexamethasone likely does not increase the risk of postoperative infections.

Endocrine

Dexamethasone is the treatment for the very rare disorder of glucocorticoid resistance.
In adrenal insufficiency and Addison's disease, dexamethasone is prescribed when the patient does not respond well to prednisone or methylprednisolone.
It can be used in congenital adrenal hyperplasia in older adolescents and adults to suppress adrenocorticotropic hormone production. It is typically given at night.

Pregnancy

Dexamethasone may be given to women at risk of delivering prematurely to promote maturation of the fetus's lungs. This administration, given from one day to one week before delivery, has been associated with low birth weight, although not with increased rates of neonatal death.
Dexamethasone has also been used during pregnancy as an off-label prenatal treatment for the symptoms of congenital adrenal hyperplasia in female babies. CAH causes a variety of physical abnormalities, notably ambiguous genitalia. Early prenatal CAH treatment has been shown to reduce some CAH symptoms, but it does not treat the underlying congenital disorder. This use is controversial: it is inadequately studied, only around one in ten of the fetuses of women treated are at risk of the condition, and serious adverse events have been documented. Experimental use of dexamethasone in pregnancy for fetal CAH treatment was discontinued in Sweden when one in five cases had adverse events.
A small clinical trial found long-term effects on verbal working memory among the small group of children treated prenatally, but the small number of test subjects means the study cannot be considered definitive.