dexamethasone


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Related to dexamethasone: Dexamethasone suppression test

dexamethasone

 [dek″sah-meth´ah-sōn]
a synthetic steroid antiinflammatory agent used for various conditions, including collagen diseases and allergic states; it is also used for replacement therapy in adrenal insufficiency and in a screening test for the diagnosis of cushing's syndrome.

dex·a·meth·a·sone

(dek'să-meth'ă-sōn),
A potent synthetic analogue of cortisol, with similar biologic action; used as an antiinflammatory agent and as a test material for adrenal cortical function.

dexamethasone

/dex·a·meth·a·sone/ (dek″sah-meth´ah-sōn) a synthetic glucocorticoid used primarily as an antiinflammatory in various conditions, including collagen diseases and allergic states; it is the basis of a screening test in the diagnosis of Cushing's syndrome; used also as the acetate or sodium phosphate salt.

dexamethasone

(dĕk′sə-mĕth′ə-sōn′, -zōn′)
n.
A synthetic glucocorticoid used to treat inflammatory disorders.

dexamethasone

[dek′səmeth′əsōn]
a long-acting synthetic adrenocorticoid with intense antiinflammatory activity and mineralocorticoid activity.
indications It is prescribed topically and systemically in the treatment of inflammatory conditions.
contraindications Systemic fungal infections or known hypersensitivity to this drug prohibits its use.
adverse effects Among the more serious adverse reactions are GI, endocrine, neurological, fluid, and electrolyte disturbances.

dex·a·meth·a·sone

(DM) (dek'să-meth'ă-sōn)
A potent synthetic analogue of cortisol, with similar biologic action; used as an antiinflammatory agent and as a test material for adrenal cortical function.

dexamethasone

A synthetic CORTICOSTEROID drug used for its anti-inflammatory action and for its value in reducing OEDEMA of the brain. It is also used to treat severe inflammatory and allergic disorders, shock, congenital adrenal hyperplasia, vomiting caused by chemotherapy, and for the diagnosis of Cushing's disease. The drug is on the WHO official list. Brand names are Decadron and Dexsol. The drug is also used in various combinations.

glucocorticoids

the group of corticosteroid hormones (mainly cortisol syn hydrocortisone, of which cortisone is the precursor) produced by the adrenal cortex, under the control of adrenocorticotrophic hormone (ACTH) from the anterior pituitary. Their major actions on nutrient metabolism have the net effect of promoting glucose and free fatty acid availability as fuels. Also vital for normal cellular processes as diverse, for example, as excitation-contraction coupling and the health of connective tissues. Synthetic steroids such as prednisolone and dexamethasone have similar actions and are used in the treatment of, for example, asthma and rheumatic conditions. Banned in sport due to their powerful anti-inflammatory action and effect of producing euphoria and masking pain. (Not to be confused with anabolic steroids). See also adrenal glands, hormones; Table 1.
Table 1: Hormones
Site of productionName of hormoneMain targetsInvolved in regulating:Secretion controlled by:
HypothalamusReleasing and inhibiting hormonesAnterior pituitary (via local blood vessels)Secretion of anterior pituitary hormonesOther brain regions; feedback re regulated hormones and their actions
Neurohormones released from posterior pituitary:
OxytocinUterus, breastsLabour and lactationAfferent information from target organs
Antidiuretic hormone (ADH, vasopressin)KidneysWater loss: ECF volume and osmolalityHypothalamic osmoreceptors
Anterior pituitary(Human) growth hormone (H)GHMost cellsGrowth and metabolismHypothalamic releasing and inhibiting hormones via local blood vessels
ProlactinBreastsMilk production
Trophic hormones:
Thyroid-stimulating (TSH)Thyroid glandThyroid secretions
GonadotrophinsOvary or testisGerm cell maturation and hormone secretions
Adrenocorticotrophic (ACTH)Adrenal cortexCortisol secretion
Pineal bodyMelatoninWidespread, including brain, thymus, etc.
  • Sleep/wake cycle
  • Antioxidant
  • Immune system
Hypothalamus; varying light input from retina
Thyroid
  • Thyroxine
  • Triiodothyronine
  • Calcitonin
  • Most cells
  • Bone, kidneys, gut
  • Cellular oxidative metabolism
  • Decreases ECF [Ca2+]
  • TSH from anterior pituitary. Negative feedback from blood hormone concentration
  • ECF [Ca2+]
ParathyroidsParathormoneBone, kidneys, gut
  • Calcium and phosphorus absorption, secretion and turnover in bone.
  • Increases ECF [Ca2+]
ECF [Ca2+]
Adrenal: Cortex
  • Cortisol
  • Aldosterone
  • Androgens
  • Most cells
  • Kidneys
  • Gonads & other tissues
  • Metabolism
  • Response to stress
  • Na and K balance
  • Sex characteristics and reproductive function
  • ACTH from anterior pituitary
  • ECF [Na+] [K+]
  • Renin-angiotensin
  • ACTH
Medulla
  • Adrenaline
  • Noradrenaline
Heart, smooth muscle, glandsCardiovascular and metabolic adjustments to activity and stressSympathetic nervous system
Atrial wallAtrial natriuretic hormoneKidneysBlood volume; increases sodium (therefore also water) loss in urineStretch of atrial wall by venous pressure
Gonads: TestisAndrogens (mainly testosterone)Genitalia and other tissuesReproductive function and sex characteristicsAnterior pituitary gonadotrophins
Ovary
  • Oestrogens
  • Progesterone
Uterus, breasts and other tissuesMenstrual cycle, pregnancy, lactation
Pancreas
  • Insulin, glucagon
  • Somatostatin
  • Most cells
  • Other secretory cells in the pancreas
Blood levels, storage and cellular uptake of nutrients, notably glucose, but also proteins and fatsBlood levels of nutrients; autonomic nervous system; other gastrointesinal hormones
Alimentary tract
StomachGastrinGastric acid-secreting cellsGastrointestinal functions: motility, digestive juices and other secretionsLocal chemical and mechanical factors in the alimentary tract
Small intestine
  • Secretin
  • Cholecystokinin- pancreozymin (CCK-PZ)
  • Somatostatin, motilin
  • Other peptide hormones including vasoactive intestinal peptide (VIP)
  • Widespread on
  • GI tract
Several GI functions including bile flow, pancreatic enzyme and exocrine secretionsIngestion of food, distension of GI tract

antiinflammatory drug 

A drug which inhibits or suppresses most inflammatory responses of an allergic, bacterial, traumatic or anaphylactic origin, as well as being immunosuppressant. They include the corticosteroids (e.g. betamethasone, dexamethasone, fluorometholone, hydrocortisone acetate, loteprednol etabonate, prednisolone, rimexolone, triamcinolone). They are sometimes combined with an antibiotic drug (e.g. betamethasone combined with neomycin or sulfacetamide, dexamethasone combined with neomycin or polymyxin B). Corticosteroids have side effects, such as enhancing the activity of herpes simplex virus, fungal overgrowth, raising intraocular pressure or cataract formation.There are other antiinflammatory drugs that are non-steroidal (NSAID) and have little toxicity. They act mainly by blocking prostaglandin synthesis. These include diclofenac sodium, flurbiprofen sodium, indomethacin, ketorolac, nepafenac and oxyphenbutazone. See immunosuppressants; steroid.

dex·a·meth·a·sone

(dek'să-meth'ă-sōn)
Potent synthetic analogue of cortisol, with similar action; used as an antiinflammatory and to test for adrenal cortical function.

dexamethasone

a synthetic glucocorticoid used primarily as an anti-inflammatory agent in various conditions, including autoimmune diseases, hypersensitivity reactions and shock; it is also used in a screening test for the diagnosis of cushing's syndrome, and for the termination of pregnancy in cattle.

dexamethasone suppression test
the determination of blood cortisol levels before and after administration of dexamethasone assists in diagnosing Cushing's syndrome and identifying the cause, depending on the protocol and dose used. Dexamethasone suppresses pituitary secretion of ACTH in normal animals and therefore the blood level of cortisol is decreased; low doses do not suppress cortisol levels in dogs with pituitary-dependent Cushing's syndrome, high doses do. Cortisol production by functional adrenal tumors is not affected by dexamethasone.
References in periodicals archive ?
Corticotropin-releasing hormone stimulation following low-dose dexamethasone administration: a new test to distinguish Cushing's syndrome from pseudo-Cushing's states.
Cells were treated in the absence or presence of dexamethasone (l[micro]M) over a time course of 24 h.
A number of studies involving critically ill patients in intensive care units have found markedly altered responsiveness of pituitary ACTH-release following suppression with dexamethasone and stimulation with hCRH (5,6).
Our study indicates that for HAPE-susceptible climbers, taking dexamethasone improved exercise capacity, oxygen uptake kinetics and decreased the anaerobic threshold," said Dr.
Between Jan 1, 2004, and April 1, 2007, the charts for all our patients who underwent perfusion of the inner ear with dexamethasone were reviewed.
The dexamethasone group received 6-mg dexamethasone at 0 hours, 12 hours, 24 hours, and 36 hours.
Dexamethasone has been found to impede this factor in cultured cells (Criscuolo & Balledux, 1996).
There is something different about the brains of people who don't suppress" dexamethasone, Dr.
Babies treated with dexamethasone had half as much chronic lung disease after the first month of life as did infants getting the saline.
The children had been given dexamethasone or dummy shots for four weeks as infants.
So researchers want to see whether within the first hour of birth is the best time for treating newborn pigs with dexamethasone.
Results from a large, phase II bridging study (MM-021) of lenalidomide and low-dose dexamethasone in 159 Chinese patients, who had relapsed or refractory multiple myeloma, also supported the submission and approval.