Metyrapone (1 brand name, 2 dosage forms, 1 route)
Available dosage forms: TABLET, CAPSULE.
Routes of administration: ORAL.
Brand Names
- METOPIRONE
Indications and Usage
Metopirone is indicated, in combination with other diagnostic tests, for the diagnosis of adrenal insufficiency in adult and pediatric patients.
Contraindications
Metopirone is contraindicated in patients with adrenal cortical insufficiency or hypersensitivity to Metopirone or to any of its excipients.
Adverse Reactions
The following adverse reactions associated with the use of Metopirone were identified in clinical trials or postmarketing reports. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Cardiovascular System:Hypotension Gastrointestinal System:Nausea, vomiting, abdominal discomfort or pain Central Nervous System:Headache, dizziness, sedation Dermatologic System:Allergic rash Hematologic System:Leukopenia, anemia, and/or thrombocytopenia
Mechanism of Action
The pharmacological effect of Metopirone is to reduce cortisol and corticosterone production by inhibiting the 11-beta-hydroxylation reaction in the adrenal cortex. Removal of the strong inhibitory feedback mechanism exerted by cortisol results in an increase in adrenocorticotropic hormone (ACTH) production by the pituitary. With continued blockade of the enzymatic steps leading to production of cortisol and corticosterone, there is a marked increase in adrenocortical secretion of their immediate precursors, 11-desoxycortisol and desoxycorticosterone, which are weak suppressors of ACTH release, and a corresponding elevation of these steroids in the plasma and of their metabolites in the urine. These metabolites are readily determined by measuring urinary 17‑hydroxycorticosteroids (17-OHCS) or 17-ketogenic steroids (17-KGS). Because of these actions, Metopirone is used as a diagnostic test, with urinary 17-OHCS measured as an index of pituitary ACTH responsiveness. Metopirone may also suppress biosynthesis of aldosterone, resulting in a mild natriuresis.
Overdosage
Death occurred in a child after two doses of Metopirone 2 g.