Metyrapone

Metopirone is indicated, in combination with other diagnostic tests, for the diagnosis of adrenal insufficiency in adult and pediatric patients.

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).

Single-Dose Short Test: 30 mg/kg at midnight Important Information Before Conducting Metopirone Testing Stop drugs affecting pituitary or adrenocortical function before administration of Metopirone in accordance with half-life of the drugs (consider at least 5 half-lives to avoid any interference with Metopirone testing). Assess ability of patient's adrenals to respond to exogenous ACTH before Metopirone is employed as a test.

Metopirone is contraindicated in patients with adrenal cortical insufficiency or hypersensitivity to Metopirone or to any of its excipients. In patients with adrenal cortical insufficiency. Hypersensitivity to Metopirone or to any of its excipients

Adrenal Insufficiency: May induce acute adrenal insufficiency. Ability of adrenals to respond to exogenous ACTH should be demonstrated before Metopirone is employed as a test. Dizziness and Sedation: May cause dizziness and sedation. Patients should not drive or operate machinery until these effects have passed

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 Adverse reactions include: hypotension, nausea, vomiting, abdominal discomfort or pain, headache, dizziness, sedation, allergic rash, leukopenia, anemia, and/or thrombocytopenia.

Anticonvulsants, psychotropic, hormone preparations, corticosteroids, antithyroid agents, cyproheptadine: may affect the results of the metyrapone test. Acetaminophen: Avoid concomitant use with Metopirone.

Store Metopirone bottles at room temperature 20°C to 25°C (68°F to 77°F), excursions permitted between 15°C and 30°C (59°F and 86°F). Keep container tightly closed and protect from heat and moisture.