Antiandrogens and androgen inhibitors

shevyatiwari's version from 2015-04-19 08:36


Question Answer
Anti androgens are those that block androgen synthesisF. Antiandrogens are those that block the AR. Androgen inhibitors block androgen syntesis
A compound is either an androgen inhibitor or an anti androgen compoundF, can be both such as progesterone and medroxyprogesterone
Th1 is associated with cell mediated immunityT
Th2 has no significant role in immunityF. Immune tolerance
DHT is converted to testosterone by 5-a-reductaseF, other way around
Tesosterone and DHT bind to the extracellular androgen receptorF, intracellular


Question Answer
Spironolactone is an androgen inhibitorF, Antiandrogen
Aldosterone antagonistT
Potent antiandrogenF, weak antiandrogen, blocks AR and inhibits androgen biosynthesiis
Inhibits 5-a-reductaseF
Converted to inactive metabolitesF, active via progesterone 17-hydroxylase
Spironolactone is a steroid molecule resembling mineralocorticoidT
BA is 90%T
Primary metabolite is canrenoneT
Canrenone has low protein bindingF, 90%.
Spirnolactone is 90% protein boundF, 98%
Food inhibits absorptionF, Increases
Metabolism is via the liver, and is rapidT
Excreted in urine and bileT. Predominant hepatobiliary.
Canrenone has a longer t1/2 than spironolactoneT
More effective than flnasteride but less effective than flutamide for hirsutismT
Menstrual abnormalities are possibleT
Hypokalaemia, gynaecomastia, GI are all S/EF, hyperkalaemia
Agranulocytosis is possible T
Should not be given to those with a history of breast cancerT
Is teratogenicT, Cat X
Significant interactions include ACE I, ARB's, aldosterone inhibitors and K rich foodT
Works witin 8 weeksF, takes 4-12 months
tesosterone/DHEAS should be monitored every 3-4 monthsT


Question Answer
All progestins bind to the PRT. Also interact with the ER, MR, GR
Progestins can act as androgensT
Second generation progestins are more androgenic than third geneerationsT
Can be given PO or SCF, PO or IM
Metabolised in the liverT
Predominant urinary excretionT
Older progestins such as progesterone or 17hydroxyprogesterone are dissimilar to testosteroneF, structurally similar
Progestins and androgens share the same ABCD ring but differ at the C-17 position, where progestins have various hydrogen extensionsF, carbon extensions
Progestins can act as a substrate for 5-a-reductaseT
The metabolite of progesterone through 5-a-reductase is similar to DHTT. That's why it's important to consider the specific progestin in women with AGA or hirsutism
Most first to third generation progestins are derived from DHTF, from estosteroen
Levonorgestrel and norgestrel are less androgenic than desogestrel, etnogestrel, gestodene, norgestimate, norelgestrominF, 2nd generations are more androgenic

Drosperinone (DRSP)

Question Answer
Synthetic progestational compoundT
Spironolactone antagonistF, analogue
Antiglucocorticoid activityF, Antimineralocorticoid and antiandrogenic. No androgenic, estrogenic or glucocorticoid activity
Sold as YazT
C/I in hepatic dysfunction, adrenal insufficiency, renal insufficiencyT
May cause hypokalaemiaF, hyperkalaemia
Yasmin contains a higher dose of DRSP than YazF, EE dose is changed, DRSP remains 3mg in both
FDA approved for moderate acne vulgariseT
UEC should be checked in the first month of therapyT

Cyproterone acetate

Question Answer
A progestinT
Competes with DHT for ART
An antiandrogenT
Weak pro gestational activityF, strong, -> suppression of gonadotropins
Can cause pseudohermaphroditismT, in the male foetus
Inhibits testosterone productionT
Can be used in AGA, hirsutism and virilisng syndromesT
Sold as DianeT


Question Answer
Binds to ART
H1 blockerF, H2
Anti androgen effects by binding to ART
A/E include loss of libido, erectile dysfunction, gynaecomastia, due to prolactin stimulationT
Weak CYP3A4 inhibitorT
Used in acne, AGA and hirsutismT
Works in 2-3 weeksF, works in 6-12 months


Question Answer
An androgen inhibitorT
Specific inhibitor of type 2 5-a-reductaseT
Binds to ARF
Decrease in DHT evident within 24 hoursT
Testosterone and estradiol also decreaseF, increase but remain WNL
Well absorbedT
ProteolysedF, metabolised in the liver
Excreted in bileF, bile and urine
Sexual contact should be avoided while on finasterideF
Myopathy is a S/ET
Associated with reduced fertility long termF
S/E worse in younger patientsF, older
Woman should not handle finasterideT
May alter immune response to cancerT
Nevirapine reduces the efficacy and levels of finasterideT
Metabolised by CYP3A4 however no significant interactions due to wide TIT
Blood transfusions are C/I in those taking finasteride for 3 monthsF, 6 months to prevent transfusion to a pregnant woman with a male foetus
Higher dose of 5mg approved for BPH - lower 1mg dose approved for AGA in menT
The only drug approved for AGA in menF, minoxidil is too
Raises testosterone in the prostateT
Significant quantities detected in semenF, only minute
Can cause depressionT
Risk reduction for prostate cancer but with higher Gleason scoresT
May modulate TH1 but not TH2F, modulates balance Th1/Th2
Does not have any secondary effects on the ARF
Cat DF, Cat X


Question Answer
Dual 5-a-reducase inhibitor like finasterideF - inhibits both type 1 and 2, finateride only inhibits type 2
FDA approved for AGAF, off label
Reproductive system S/E as finasterideT
Increases risk of prostate cancerF, reduces, similar to finasteride
Metabolised by CYP3A4 and like finasteride - interactions are not significantF, interactions are important
Women should not handle dutasteride if pregnantT
Blood donations need to be avoided for 1 yearF, 6 months
Highly electropositive moleculeF, electronegative
Short terminal half lifeF, long - 5 weeks
Inhibits 90% of DHT in 24 hoursT
Possibly more efficacious however more S/E than finasteirdeT
Increased duration of treatment is associated with increased sexual S/EF, decrease
Ketoconazole, ritonavir, verapamil, diltiazem, cimetidine, ciprofloxacin all reduce levels of dutatserideF, increase. Unlike finasteride


Question Answer
Inhibits CYP3A4 enzymes involved in steroid biosynthesisT
Higher doses than for infections are required for androgen inhibitionT
Potential for hepatotoxicityT
Can be used for hirsutismT
Increases production of glucocorticoids and androgenic steroidsF, decreases
Promotes testicular synthesis of androgens and displacement of sex steroids from sex hormone binding globulinF, inhibits

OCP's, transdermals, gels, injectables, IUD's

Question Answer
Most estrogen in OCP's is mestranolF, ethinyl estradiol. Mestranol occasionally used
Mestranol is more potent than ethinyl estradiolF. Is about 1/5 to 1/3 as potent as EE
Synthetic progestins are derived from 19-nortestosteroneT
Those with acne or hirsutism should take androgens with a high progestin indexF
Rifampicin and griseofulvin are probably the only antimicrobial agents which reduce the efficacy of the OCPT

GnRH analogues

Question Answer
Leuprolide or naficillin are examplesF, nafarelin not naficillin
Cause sustained increases in FSH an LHF, only for 2-4 weeks before inhibition
Are possibly useful in hirsutism however are expensiveT
require regular monitoring by a gynaecologistT

Herbal Remedies

Question Answer
Saw Palmetto Plus is from berry extractT, not from dried berries
Saw Palmetto Plus claims to be an inhibitor of type 1 and 2 5-a-reductaseT
Green tea, pygeum, stinging nettle, spearmint herbal tea, Zn, azaleic acid, methanol extract may have anti androgenic propertiesT

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