Chemically Dexamethasone is 9-Fluoro-11ß, 17, 21-trihydroxy-16a-methylpregna-1, 4-diene-3, -20-dione. Dexamethasone is a corticosteroid. It reduces swelling and inflammation. Dexamethasone is used in different conditions such as skin diseases, allergic conditions, breathing problems, cancer, blood disorders, eye diseases and in arthritis. Dexamethasone is also used to treat nausea and vomitting produced by cancer chemotherapy;.
Dexamethasone Sodium Phospate is the derivative of Dexamethasone. It is of Synthetic origin and belongs to Steroid. It belongs to Glucocorticoid agonist pharmacological group on the basis of mechanism of action and also classified in Corticosteroid Nasal pharmacological group.The Molecular Weight of Dexamethasone is 392.50. It is weakly alkaline drug, 6.75% solution of the drug is isotonic.
Oral absorption of Dexamethasone is found to be 90% . Volume of distribution is found to be 0.58 l/kg (0.8-1l/kg) and plasma protien binding is 66-77%. and metabolism is reported slow via liver. Renal Excretion accounts for 60% and plasma half life is 3.6 ± 0.9 hr (3.5).
Dexamethasone is primarily indicated in conditions like
Adrenocortical insufficiency, Anorexia in palliative care, Brain tumors, Cerebral oedema, Congenital adrenal hyperplasia, Dyspnoea, Dyspnoea in palliative care, Headache due to raised intracranial pressure in palliative care, Nausea and vomiting (chemotherapy induced), Pain due to nerve compression in palliative care, Palliative surgery., Raised intracranial pressure, Respiratory distress syndrome, Shock, Suppression of inflammatory and allergic disorders, and can also be given in adjunctive therapy as an alternative drug of choice in Asthma, Blood disorders, Connective tissue diseases, GI diseases, Liver diseases, Malignancy, Ocular diseases, osteoarthiritis of superficial joints, Osteoarthritis, Renal diseases.
Dexamethasone is known to interact with other drugs, the details of drug interactions is as follows:
Drug Details Severity Onset Management Albendazole Aminoglutethimide Aminoglutethimide accelerates the metabolism of Dexamethasone (reduced effects). Aprepitant Increased the AUC of dexamethasone, a CYP3A4 substrate, by 2.2-fold on Days 1 and 5 of chemotherpy when given in regimen. The oral dexamethasone doses should be reduced by approximately 50% when coadministered with aprepitant capsules)(125 mg/80 mg regimen), to achieve exposures of dexamethasone similar to those obtained when it is given without aprepitant capsules. A single dose of aprepitant capsules (40 mg) when coadministered with a single oral dose of dexamethasone 20 mg, increased the AUC of dexamethasone by 1.45-fold. Therefore, no dose adjustment is recommended. Carbamazepine carbamazepine increase clearance of cortisteroids. Diazoxide Hypotensive effect of Diazoxide antagonised by Dexamethasone. Dolasetron (Mesylate) Ephedrine Ephedrine Ephedrine increase urinary excretion of Dexamethasone Fosphenytoin Granisetron (HCl) Iloprost Indinavir (Sulphate) Natamycin Concurrent use may increase the toxicity, therefore concomitant use is contraindicated.
Nateglinide Concurrent use may reduce the hypoglycemic action of Nateglinide. Oxandrolone The concomitant administration of oxandrolone and adrenal cortical steroids may increase the edema in patients with edema. The mechanism and clinical significance are unknown. Closer monitoring may be appropriate, especially in patients with conditions that may be aggravated by fluid retention. Minor Perindopril Theoretical potential for DEXAMETHASONE [ORAL] reducing the HYPOTENSIVE effect of Perindopril Erbumine. Moderate Phenobarbitone phenobarbitone decrease plasma half life and bioavailibility of dexamethasone by 50% Phenytoin (Na) Phenytoin (Na) Rhubarb Potassium deficiency can be increased by concurrent use. Rifampicin Ritonavir Saquinavir Sorafenib may also increase metabolism of sorafenib and thus decrease sorafenib concentrations. Sunitinib May decrease sunitinib concentrations. Technetium Tc-99m Gluceptate Uptake of technetium Tc 99m gluceptate in cerebral tumor or abscess may be decreased because of reduced peritumor edema caused by the Dexamethasone. Technetium Tc-99m Oxidronate Long-term therapy with glucocorticoids may induce bone mineral depletion, thus causing decreased bone uptake of technetium Tc 99m oxidronate. VORICONAZOLE Voriconazole may increase the serum concentration of dexamethasone by decreasing its metabolism Monitor for changes in the therapeutic and adverse effects of dexamethasone if voriconazole is initiated, discontinued or dose changed.
These interactions are sometimes beneficial and sometimes may pose threats to life. Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Interference in Pathology
Measurement of Serum Digoxin by Immunoassay.
Impairment of Glucose Tolerance
Lowers basal TSH, FSH and LH Levels
Reduced levels of Prolactin
Reuces hGH response to various stimuli Lowering of Plasma cortisol,Potassium, and Oestrogens
The severe or irreversible adverse effects of Dexamethasone, which give rise to further complications include Glaucoma, Peptic ulceration, Myopathy, Osteoporosis, Posterior subcapsular cataract, Growth retardation, Aseptic bone necrosis, Ocular hypertension, Subcapsular cataract, Pancreatic disturbance, Cushing like features, Oedema, Retinal detachment, Moon face, Truncal obesity, Negative calcium balance.
Dexamethasone produces potentially life-threatening effects which include Collapse, Suppression of hypothalamus-pituitary-adrenal axis. which are responsible for the discontinuation of Dexamethasone therapy.
The symptomatic adverse reactions produced by Dexamethasone are more or less tolerable and if they become severe, they can be treated symptomatically, these include Nausea, Vomiting, Insomnia, Nervousness, Nocturia, Increased appetite, Obesity, Facial rounding, Fragility of skin, Euphoria, Glucose intolerance, nervousness, Nervousness, adrenal suppression, protein catabolism, lipid metabolism.
Click on the appropriate strength of the dosage form to view its available brands.
Single Ingredient Inj: 4 mg, 20 mg, 2 mg/ml, 4 mg/ml, Eye Drops: 1 mg, 0.1 %w/v, 0.1 %w/w, Oint: 0.1 %w/w, Tabs: 0.5 mg, Multi ingredient
Drops: 1 mg, 0.1 %w/v, Eye Drops: 1 mg, 0.1 %, 0.1 %w/v, 0.2 %w/v, Ear Drops: 0.1 %, 0.1 %w/v, Eye Oint: 0.1 %w/w, E and E Drops: 0.1 %w/v, Oint: 0.1 gm, Cream: 1 mg, 4 mg, 0.1 gm, 0.1 %w/w, 0.4 %w/w, 0.04 %w/w, 3500 IU/g,
Dexamethasone's dosage details are as follows:
0.5 to 24 mg 12 (12.25) As recommended. IV,IM Once in Weeks 0.1 % 0.1 (0.1) As recommended. Ophthalmic As Required.To be given as drops.
0.5 to 10 mg 5.2 (5.25) 24 hourly PO
Paedriatic Dosage ( 20 Kg. )
20.8 mg 21 (20.8) 6 hourly Intra Venous Initial dose followed by 3.3mg till 8th day then by daily reduction of 1.7mg.For 35 kg and over 20.8 mg 21 (20.8) As recommended. IV Initial dose . The follow up is same This dose is for children below 35 kg. 1 % 1 (1) 6 hourly Opthalmic 1 to 2 drops
0.01 to 0.1 mg/kg 0.055 (0.055) 24 hourly Oral daily
Neonatal Dosage ( 3 Kg. )
0.2 mg/kg 0.2 (0.2) 8 hourly Intramuscular 0.2 mg/kg 0.2 (0.2) 8 hourly Intravenous
0.2 mg/kg 0.2 (0.2) 8 hourly oral
High Risk Groups
Drug should not be given to Paediatrics, Pregnant Mothers, Cardiac / Hypertensive Patients, Geriatrics, and Neonates.
If prescribing authority justifies the benefits of the drug against the possible damages he/she should reevaluate them and consult the reference material and previous studies.
Warning / Precautions
Dexamethasone should be used with caution in patients with active tuberculosis infection of respiratory tract or in untreated fungal, bacterial or systemic viral infections. Corticosteroids should only be used systemically with great caution in the presence of congestive heart failure (CHF), recent myocardial infraction (MI), hypertension, diabetes mellitus, epilepsy, glaucoma, hypothyroidism, liver failure, osteoprosis,
peptic ulceration or renal impairment. Children may be at increase risk of some adverse effects, corticosteroid cause growth retardation and prolonged use is rarely justified. Passive immunization is recommended to non-immune patients who do come in contact with chickenpox or measles. Live vaccine should not be given to patients receiving high dose systemic corticosteroid therapy nor for atleast 3 months afterwards, killed vaccine or toxoids may be given, although the response may be attenuated. During prolong treatment with corticosteroids, patients should be examined regularly, sodium intake may need to be reduced and calcium and potassium supplement may be necessary. Patient should carry cards given full details of their corticosteroid therapy. Avoid use during pregnancy. Use nasal steroids with caution until healing has occurred.
Dose adjustment required in patient with renal
Inj, Cream, Gel, Ear Soln, Eye Oint, Soln or Susp
Store Below 30°C. Do not Freeze. Protect from Sunlight.
Oral Inhaler, Nasal Aerosol
Store at room temperature, Below 40°C. Do not Freeze.
Tab, Oral Elixir, Oral Soln
Store in a well closed container, Below 40°C.
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