Dexamethasone Information
Dexamethasone ()
Dexamethasone () Description
Dexamethasone () , USP ……….. 0.5 mg
Benzoic Acid, USP …..…… 0.1% w/v (as preservative)
Alcohol ……………………. 5.1% v/v
Glucocorticoids are adrenocortical steroids, both naturally occurring and synthetic, which are readily absorbed from the gastrointestinal tract.
Dexamethasone () , a synthetic adrenocortical steroid, is a white to practically white, odorless, crystalline powder. It is stable in air. It is practically insoluble in water. The molecular weight is 392.47. It is designated chemically as 9-fluoro-11β,17,21-trihydroxy-16α-methylpregna-1, 4-diene-3,20-dione. The molecular formula is CHFO and the structural formula is:
Dexamethasone () Clinical Pharmacology
Naturally occurring glucocorticoids (hydrocortisone and cortisone), which also have salt-retaining properties, are used as replacement therapy in adrenocortical deficiency states. Their synthetic analogs, including Dexamethasone () , are primarily used for their potent anti-inflammatory effects in disorders of many organ systems.
Glucocorticoids cause profound and varied metabolic effects. In addition, they modify the body's immune responses to diverse stimuli.
At equipotent anti-inflammatory doses, Dexamethasone () almost completely lacks the sodium-retaining property of hydrocortisone and closely related derivatives of hydrocortisone.
Dexamethasone () Indications And Usage
1. Primary or secondary adrenocortical insufficiency (hydrocortisone or cortisone is the first choice; synthetic analogs may be used in conjunction with mineralocorticoids where applicable; in infancy mineralocorticoid supplementation is of particular importance). Congenital adrenal hyperplasia Nonsuppurative thyroiditis Hypercalcemia associated with cancer
2. As adjunctive therapy for short-term administration (to tide the patient over an acute episode or exacerbation) in: Psoriatic arthritis Rheumatoid arthritis, including juvenile rheumatoid arthritis (selected cases may require low-dose maintenance therapy) Ankylosing spondylitis Acute and subacute bursitis Acute nonspecific tenosynovitis Acute gouty arthritis Post-traumatic osteoarthritis Synovitis of osteoarthritis Epicondylitis
3. During an exacerbation or as maintenance therapy in selected cases of: Systemic lupus erythematosus Acute rheumatic carditis
4. Pemphigus Bullous dermatitis herpetiformis Severe erythema multiforme (Stevens-Johnson syndrome) Exfoliative dermatitis Mycosis fungoides Severe psoriasis Severe seborrheic dermatitis
5. Control of severe or incapacitating allergic conditions intractable to adequate trials of conventional treatment: Seasonal or perennial allergic rhinitis Bronchial asthma Contact dermatitis Atopic dermatitis Serum sickness Drug hypersensitivity reactions
6. Severe acute and chronic allergic and inflammatory processes involving the eye and its adnexa, such as: Allergic conjunctivitis Keratitis Allergic corneal marginal ulcers Herpes zoster ophthalmicus Iritis and iridocyclitis Chorioretinitis Anterior segment inflammation Diffuse posterior uveitis and choroiditis Optic neuritis Sympathetic ophthalmia
7. Symptomatic sarcoidosis Loeffler's syndrome not manageable by other means Berylliosis Fulminating or disseminated pulmonary tuberculosis when used concurrently with appropriate antituberculous chemotherapy Aspiration pneumonitis
8. Idiopathic thrombocytopenic purpura in adults Secondary thrombocytopenia in adults Acquired (autoimmune) hemolytic anemia Erythroblastopenia (RBC anemia) Congenital (erythroid) hypoplastic anemia
9. For palliative management of: Leukemia and lymphomas in adults Acute leukemia of childhood
10. To induce a diuresis or remission of proteinuria in the nephrotic syndrome, without uremia, of the idiopathic type or that due to lupus erythematosus
11. To tide the patient over a critical period of the disease in: Ulcerative colitis Regional enteritis
12. Tuberculous meningitis with subarachnoid block or impending block when used concurrently with appropriate antituberculous chemotherapy Trichinosis with neurologic or myocardial involvement
13.
Dexamethasone () Contraindications
Systemic fungal infections Hypersensitivity to this product
Dexamethasone () Warnings
In patients on corticosteroid therapy subjected to unusual stress, increased dosage of rapidly acting corticosteroids before, during, and after the stressful situation is indicated.
Drug-induced secondary adrenocortical insufficiency may result from too rapid withdrawal of corticosteroids and may be minimized by gradual reduction of dosage. This type of relative insufficiency may persist for months after discontinuation of therapy; therefore, in any situation of stress occurring during that period, hormone therapy should be reinstituted. If the patient is receiving steroids already, dosage may have to be increased. Since mineralocorticoid secretion may be impaired, salt and/or a mineralocorticoid should be administered concurrently.
Corticosteroids may mask some signs of infection, and new infections may appear during their use. There may be decreased resistance and inability to localize infection when corticosteroids are used. Moreover, corticosteroids may affect the nitroblue-tetrazolium test for bacterial infection and produce false-negative results.
In cerebral malaria, a double-blind trial has shown that the use of corticosteroids is associated with prolongation of coma and a higher incidence of pneumonia and gastrointestinal bleeding.
Corticosteroids may activate latent amebiasis. Therefore, it is recommended that latent or active amebiasis be ruled out before initiating corticosteroid therapy in any patient who has spent time in the tropics or any patient with unexplained diarrhea.
Prolonged use of corticosteroids may produce posterior subcapsular cataracts, glaucoma with possible damage to the optic nerves, and may enhance the establishment of secondary ocular infections due to fungi or viruses.
Dexamethasone () Precautions
Following prolonged therapy, withdrawal of corticosteroids may result in symptoms of the corticosteroid withdrawal syndrome including fever, myalgia, arthralgia, and malaise. This may occur in patients even without evidence of adrenal insufficiency.
There is an enhanced effect of corticosteroids in patients with hypothyroidism and in those with cirrhosis.
Corticosteroids should be used cautiously in patients with ocular herpes simplex because of possible corneal perforation.
The lowest possible dose of corticosteroid should be used to control the condition under treatment, and when reduction in dosage is possible, the reduction should be gradual.
Psychic derangements may appear when corticosteroids are used, ranging from euphoria, insomnia, mood swings, personality changes, and severe depression, to frank psychotic manifestations. Also, existing emotional instability or psychotic tendencies may be aggravated by corticosteroids.
Aspirin should be used cautiously in conjunction with corticosteroids in hypoprothrombinemia.
Steroids should be used with caution in nonspecific ulcerative colitis, if there is a probability of impending perforation, abscess, or other pyogenic infection, diverticulitis, fresh intestinal anastomoses, active or latent peptic ulcer, renal insufficiency, hypertension, osteoporosis and myasthenia gravis. Signs of peritoneal irritation following gastrointestinal perforation in patients receiving large doses of corticosteroids may be minimal or absent. Fat embolism has been reported as a possible complication of hypercortisonism.
When large doses are given, some authorities advise that corticosteroids be taken with meals and antacids taken between meals to help to prevent peptic ulcer.
Growth and development of infants and children on prolonged corticosteroid therapy should be carefully observed.
Steroids may increase or decrease motility and number of spermatozoa in some patients.
Phenytoin, phenobarbital, ephedrine, and rifampin may enhance the metabolic clearance of corticosteroids, resulting in decreased blood levels and lessened physiologic activity, thus requiring adjustment in corticosteroid dosage. These interactions may interfere with Dexamethasone () suppression tests which should be interpreted with caution during administration of these drugs.
False-negative results in the Dexamethasone () suppression test (DST) in patients being treated with indomethacin have been reported. Thus, results of the DST should be interpreted with caution in these patients.
The prothrombin time should be checked frequently in patients who are receiving corticosteroids and coumarin anticoagulants at the same time because of reports that corticosteroids have altered the response to these anticoagulants. Studies have shown that the usual effect produced by adding corticosteroids is inhibition of response to coumarins, although there have been some conflicting reports of potentiation not substantiated by studies.
When corticosteroids are administered concomitantly with potassium-depleting diuretics, patients should be observed closely for development of hypokalemia.
Dexamethasone () Adverse Reactions
Other cutaneous reactions, such as allergic dermatitis, urticaria, angioneurotic edema
Dexamethasone () Overdosage
Reports of acute toxicity and/or death following overdosage of glucocorticoids are rare. In the event of overdosage, no specific antidote is available; treatment is supportive and symptomatic.
The oral LD of Dexamethasone () in female mice was 6.5 g/kg.
Dexamethasone () Dosage And Administration
DOSAGE REQUIREMENTS ARE VARIABLE AND MUST BE INDIVIDUALIZED ON THE BASIS OF THE DISEASE AND THE RESPONSE OF THE PATIENT.
The initial dosage varies from 0.75 to 9 mg a day depending on the disease being treated. In less severe diseases doses lower than 0.75 mg may suffice, while in severe diseases doses higher than 9 mg may be required. The initial dosage should be maintained or adjusted until the patient's response is satisfactory. If satisfactory clinical response does not occur after a reasonable period of time, discontinue Dexamethasone () elixir and transfer the patient to other therapy.
After a favorable initial response, the proper maintenance dosage should be determined by decreasing the initial dosage in small amounts to the lowest dosage that maintains an adequate clinical response.
Patients should be observed closely for signs that might require dosage adjustment, including changes in clinical status resulting from remissions or exacerbations of the disease, individual drug responsiveness, and the effect of stress (e.g., surgery, infection, trauma). During stress it may be necessary to increase dosage temporarily.
If the drug is to be stopped after more than a few days of treatment, it usually should be withdrawn gradually.
The following milligram equivalents facilitate changing to Dexamethasone () elixir from other glucocorticoids:
Dexamethasone () How Supplied
Dexamethasone () Elixir USP, 0.5 mg/5 mL is supplied as a clear, red, raspberry-flavored liquid in bottles of 8 fl oz (237 mL).
Dexamethasone ()
Dexamethasone () Principal Display Panel
