2 - Antiandrogens and Androgen Inhibitors Flashcards
Androgens influence cutaneous structures such as hair follicles and sebaceous glands
True
Free testosterone and dihydrotestosterone are biologically active androgens that affect the pilosebaceous unit
True
Dihydrotestosterone is the target tissue active androgen
True
Testosterone and dihydrotestosterone have a central role in the pathogenesis of androgenetic alopecia, acne vulgaris and hirsutism
True
Antiandrogen refers to agents that block the androgen receptor I.e. Spironolactone, flutamide and cyproterone acetate
True
Spironolactone is an antiandrogen (blocks the androgen receptor)
True
Flutamide is an antiandrogen (blocks the androgen receptor)
True
Androgen inhibitors block androgen synthesis
True
Finasteride and Dutasteride are androgen inhibitors that specifically inhibit 5-alpha reductase
True (less conversion of free testosterone to dihydrotestosterone)
Leuprolide is a gonadotropin-releasing hormone agonist that initially increases LH and FSH production by the pituitary before sustained feedback inhibition of the secretion of these 2 gonadotropins
True
Progesterone and medroxyprogesterone act as both antiandrogens (block androgen receptor) and androgen inhibitors (inhibit dihydrotestosterone formation via 5-alpha reductase inhibition)
True
Finasteride (type II 5-alpha reductase inhibitor) is FDA approved for men with androgenetic alopecia
True (in contrast, the more potent Dutasteride is FDA approved for benign prostatic hypertrophy but not for androgenetic alopecia due to blockade of both isoenzymes I and II of 5-alpha reductase)
Testosterone can be formed in cutaneous sites, from the androgen precursor androstenedione derived from the adrenal cortex
True (this occurs when large amounts of androstenedione are secreted by adrenal tumours or in congenital adrenal hyperplasia)
The ovary and adrenal cortex are the primary sources of testosterone and other androgens in women
True
Androstenedione and dehydroepiandrosterone (DHEA) are produced by the ovary and adrenal gland
True
Androstenedione and dehydroepiandrosterone (DHEA) produced by the ovary and adrenal gland can be converted to more potent androgens I.e. Testosterone or to Oestrogens in peripheral organs including skin
True
The average daily rate of testosterone production in women is approx 0.25mg with half of this derived from metabolic conversion of androstenedione to testosterone at extra glandular sites including skin
True
PCOS is caused by increased quantities of androgens secreted by the ovary resulting in alopecia, acne and hirsutism
True
The 2 isoenzyme forms of 5-alpha reductase are type I and type II
True
Testosterone has minimal biological activity at the pilosebaceous unit and prostate until it is converted to dihydrotestosterone by 5-alpha reductase
True
Both testosterone and dihydrotestosterone bind to intracellular androgen receptor
True
Both type I and type II forms of 5-alpha reductase are located in the pilosebaceous unit
True
Type II isoenzyme form of 5-alpha reductase is also found in the prostate gland, epididymis and seminal vesicles (genital skin)
True
Type I isoenzyme form of 5-alpha reductase is found in non-genital skin
True (also includes scalp and face)
The hair follicles and sebaceous glands ducts on top of the scalp from frontal to vertex scalp host the Type II isoenzyme of 5-alpha reductase
True
The type II isoenzyme of 5-alpha reductase is absent from the occipital scalp
True
Spironolactone is an aldosterone antagonist which also blocks the androgen receptor
True
Spironolactone has no effect on 5-alpha reductase
True
Spironolactone is a steroid molecule which resembles mineralocorticoids
True (aldosterone antagonist with anti-mineralocorticoid activity)
Spironolactone may be converted to other active metabolites via progesterone 17-hydroxylase with the net result of decreased testosterone and dihydrotestosterone production
True
Spironolactone is 98% protein bound
True
Canrenone is the primary metabolite of Spironolactone contributing to the diuretic and antiandrogen activities of Spironolactone
True
The liver rapidly metabolised Spironolactone to its primary and active aldosterone antagonist metabolite, Canrenone
True
Food increases the absorption of Spironolactone
True
Metabolites of Spironolactone (active metabolite canrenone, and inactive canrenoate which is converted from canrenone by hydrolysis) are excreted in urine and bile
True
The unmetabolised Spironolactone does not appear in the urine
True (only the metabolised metabolites of spironolactone Canrenone and Canrenoate appear in the urine)
Spironolactone has been used to treat hirsutism, acne and androgenetic alopecia
True
Flutamide is more effective than Spironolactone in improving hirsutism
True
Spironolactone is more effective than Finasteride in improving hirsutism
True
Spironolactone may commonly cause menorrhagia and other menstrual dysfunction which usually last during the first 2-3 months of therapy
True
Finasteride specifically inhibits the type II isoenzyme of 5-alpha reductase
True
Dutasteride inhibits both type I and type II isoenzymes of 5-alpha reductase
True
Hyperkalaemia is a potentially serious common adverse effect of Spironolactone, particularly if given to patients with severe renal insufficiency
True
Spironolactone may cause gynaecomastia
True