Metyrapone

Metyrapone

Metyrapone
Systematic (IUPAC) name
2-methyl-1,2-di(pyridin-3-yl)propan-1-one
Clinical data
Trade names Metopirone
AHFS/Drugs.com
Pregnancy cat.
Legal status
?
Routes Oral
Pharmacokinetic data
Half-life 1.9 ±0.7 hours.
Identifiers
CAS number  YesY
ATC code V04
PubChem
DrugBank
ChemSpider  YesY
UNII  YesY
KEGG  YesY
ChEBI  YesY
ChEMBL  YesY
Chemical data
Formula C14H14N2O 
Mol. mass 226.274 g/mol
 YesY   

Metyrapone (trade name Metopirone) is a drug used in the diagnosis of adrenal insufficiency and occasionally in the treatment of Cushing's syndrome (hypercortisolism).

Contents

  • Mechanism 1
  • Uses 2
    • Experimental use 2.1
  • References 3
  • See also 4
  • External links 5

Mechanism

Metyrapone blocks cortisol synthesis[1] by inhibiting steroid 11β-hydroxylase. This stimulates ACTH secretion, which in turn increases plasma 11-deoxycortisol levels.

Uses

Metyrapone can be used in the diagnosis of adrenal insufficiency. Metyrapone 30 mg/kg, maximum dose 3000 mg, is administered at midnight usually with a snack. The plasma cortisol and 11-deoxycortisol are measured the next morning between 8:00 and 9:00 am. A plasma cortisol less than 220 nmol/l indicates adequate inhibition of 11β-hydroxylase. In patients with intact Hypothalamo-pituitary-adrenal axis, CRH and ACTH levels rise as a response to the falling cortisol levels. This results in an increase of the steroid precursors in the pathway. Therefore if 11-deoxycortisol levels do not rise and remains less than 7 µg/dl (202 nmol/l) and ACTH rises, then it is highly suggestive of adrenal insufficiency, if neither 11-deoxycortisol nor ACTH rise it is highly suggestive of an impaired HPA axis at either the pituitary or hypothalamus.

Metyrapone test may aid in verifying the cause of Cushing's syndrome. Most patients with pituitary dysfunction and/or pituitary microadenoma will increase ACTH secretion in response to metyrapone, while most ectopic ACTH-producing tumors will not. Pituitary macroadenomas do not always respond to metyrapone.

Experimental use

Metyrapone has been found in early human trials to reduce recollection of emotional memories in normal volunteers. The volunteers showed significant impairment in ability to retrieve memories with negative emotional content while not impairing memories with neutral content. This has significant implication in the study of the process of emotional healing in post traumatic stress disorder.[2][3]

Due to the permissive action of cortisol on glucagon partial blockade of cortisol may reduce the effects of circulating glucagon in chronically increasing blood glucose in Syndrome X / type 2 diabetes.

References

  1. ^ Young EA, Ribeiro SC, Ye W (June 2007). "Sex Differences in ACTH Pulsatility following Metyrapone Blockade in Patients with Major Depression". Psychoneuroendocrinology 32 (5): 503–7.  
  2. ^ University of Montreal (27 May 2011). "Drug may help overwrite bad memories". Science Daily (online: ScienceDaily). Retrieved 27 May 2011. 
  3. ^ Marin, Marie-Frances; A. Hupbach; F. S. Maheu; K. Nader; S. J. Lupien. "Metyrapone Administration Reduces the Strength of an Emotional Memory Trace in a Long-Lasting Manner". Journal of Clinical Endocrinology & Metabolism. early release abstract (8): E1221.  

See also

External links

Huffington Post reports that Metyrapone may someday by used to manage PTSD by weakening those bad memories while keeping the good ones strong.