Anesthesia Pharmacology: Physiology and Pharmacology: Adrenocorticosteroids / Adrenocortical Antagonists
Congenital adrenal hyperplasia
|
|
Caused by cortisol synthetic defects
Autosomal recessive mutations
Most common adrenal disorder of childhood and infancy
Late-onset adrenal hyperplasia cause:
5%-25% of hirsuitism and oligomenorrhea cases in women
Pregnancy at risk for congenital adrenal hyperplasia:
Dexamethasone administration to the mother is protective.
Decrease or lack of cytochrome P450c21 (21ß hydroxylase) activity {95% frequency) which results in:
Cortisol synthesis reduction
Compensatory increase of ACTH release
Other deficiencies:
P450c18, P450c17a , P450c11ß, 3ß- hydroxysteroid dehydrogenase
Increased compensatory ACTH can result in normal cortisol levels if sufficient P450c21 activity is present; however the gland will:
Become hyperplastic
Produce excessive precursors such as 17-hydroxyprogesterone -- diverted to androgen pathways-- leading to virilization.
Diagnosis:
Excessive 17-hydroxyprogesterone is metabolized in the liver to pregnanetriol, detected in large amounts in the urine.
Most reliable detection: increased plasma 17-hydroxyprogesterone to ACTH stimulation
Female:
Adrenal virilization associated with:
Ambiguous external genitalia (female pseudohermaphroditism)
Enlargement of the clitoris
Partial/complete labial fusion
Urogenital sinus (possible)
Male: enlarged genitalia
Postnatal period:
Female virilization
Isosexual prococity in the male
Excessive androgen levels:
Accelerated growth
Early epiphyseal closure; growth stops --truncal development continues-- (short child with well-developed trunk.
Excessive desoxycorticosterone production: hypertension
Adrenal and gonadal defects increased 11-desoxycorticosterone levels-- mineralocorticoid excess signs/symptoms:
Hypertension
Hypokalemia
Infant with congenital adrenal hyperplasia: Presenting Symptoms
Treatment
If acute adrenal crisis:
IV cortisol
Mineralocorticoid
Electrolyte solutions
After stabilization:
Hydrocortisone (Cortef, Solu-Cortef)-- adjusted as required
Alternative: prednisone (Deltasone)
Mineralocorticoids may be required (fludrocortisone (Florinef))
Goldfien, A.,Adrenocorticosteroids and Adrenocortical Antagonists, in Basic and Clinical Pharmacology, (Katzung, B. G., ed) Appleton-Lange, 1998, pp 635-650.
Williams, G. H and Dluhy, R. G. , Diseases of the Adrenal Cortex, In Harrison's Principles of Internal Medicine 14th edition, (Isselbacher, K.J., Braunwald, E., Wilson, J.D., Martin, J.B., Fauci, A.S. and Kasper, D.L., eds) McGraw-Hill, Inc (Health Professions Division), 1998, pp 2035-2056
This Web-based pharmacology and disease-based integrated teaching site is based on reference materials, that are believed reliable and consistent with standards accepted at the time of development. Possibility of human error and on-going research and development in medical sciences do not allow assurance that the information contained herein is in every respect accurate or complete. Users should confirm the information contained herein with other sources. This site should only be considered as a teaching aid for undergraduate and graduate biomedical education and is intended only as a teaching site. Information contained here should not be used for patient management and should not be used as a substitute for consultation with practicing medical professionals. Users of this website should check the product information sheet included in the package of any drug they plan to administer to be certain that the information contained in this site is accurate and that changes have not been made in the recommended dose or in the contraindications for administration. Advertisements that appear on this site are not reviewed for content accuracy and it is the responsibility of users of this website to make individual assessments concerning this information. Medical or other information thus obtained should not be used as a substitute for consultation with practicing medical or scientific or other professionals. |