Oral Diagnostic test in differentiating pituitary and ectopic production of ACTH in patients with ACTH-dependent Cushing's syndrome
Adult: For single-dose test: 30 mg/kg at midnight. Max: 3 g. For multiple-dose test: 750 mg every 4 hours for 6 doses. Child: For single-dose test: Same as adult dose. For multiple-dose test: 15 mg/kg (Min 250 mg and Max 750 mg) every 4 hours for 6 doses.
Oral Resistant oedema
Adult: In combination with glucocorticoid: 3,000 mg daily in divided doses.
Oral Cushing's syndrome
Adult: 250 mg to 6,000 mg daily in divided doses, adjusted according to patient’s requirement.
Should be taken with food. Take w/ milk or yoghurt or after a meal.
Adrenal cortical insufficiency.
Patient with hypo-or hyperthyroidism, reduced adrenal secretory capacity, gross hypopituitarism, ectopic Cushing’s syndrome. Hepatic impairment. Children. Pregnancy and lactation.
This drug may cause dizziness and sedation, if affected, do no drive or operate machinery.
Monitor for signs and symptoms of acute adrenal insufficiency.
Symptoms: Gastrointestinal symptoms (e.g. vomiting, nausea, epigastric pain, diarrhoea), acute adrenocortical insufficiency, cardiac arrhythmias, hypotension, dehydration, anxiety, confusion, weakness, impairment of consciousness, hyponatremia, hypochloraemia, hyperkalaemia. Management: Perform gastric lavage, forced emesis and administration of large dose hydrocortisone, together with IV saline and glucose infusion to reduce drug absorption. Repeat if necessary according to patient’s condition. Monitor blood pressure, fluid and electrolyte imbalance.
Decreased serum concentration with phenytoin. May increase serum concentration and potentiate acetaminophen toxicity. Amitriptyline, chlorpromazine, barbiturates, corticosteroids, cyproheptadine may affect the result of metyrapone test.
Description: Metyrapone is a diagnostic agent that inhibits 11β-hydroxylase enzyme in the adrenal cortex hence, blocking the synthesis of cortisol and corticosterone production resulting to increase adrenocorticotropic hormone (ACTH) production thereby, increasing cortisol precursors in the urine (17-hyroxycorticosteroids [17-OHCS] and 17-ketogenic steroids [17-KGS]). Onset: Peak steroid secretion: Within 24 hours. Pharmacokinetics: Absorption: Rapidly absorbed from the gastrointestinal tract. Time to peak plasma concentration: 1 hour. Distribution: Enters breast milk. Metabolism: Metabolised in the liver via rapid reduction of the ketone to active metabolite, metyrapol. Both parent drug and metabolite also undergoes glucuronide conjugation. Excretion: Mainly via urine (approx 5%, as metyrapone; approx 38%, as metyrapol). Elimination half-life: Approx 1.9 hours.
V04CD01 - metyrapone ; Belongs to the class of diagnostic agents used to test for pituitary function.
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