Androgen Suppression Flashcards
1
Q
What are the methods of Androgen Suppression?
A
- Leuprolide, Goserelin, Nafraelin, Buserelin
- Finasteride (Proscar, Propecia)
- Dutasteride (Avodartp)
- Ketoconazole (Nizoral)
- Cimetidine (Tagamet)
2
Q
What are the characteristics of Leuprolide, Goserelin, Nafraelin, Buserelin?
A
- Synthetic GnRH analog agonists
- Initially increases release of LH and hence ↑ testosterone - but with continued dosing LH and FSH release is dramatically
decreased - Testosterone surge (“androgen
flare”) at first then drop in LH which decreases testosterone production) - Long-term action is to inhibit the release of testosterone
( exact opposite effect occurs when dosed in a pulsatile fashion)
3
Q
What are the characteristics of Finasteride (Proscar, Propecia)?
A
- MOA – inhibitor of predominantly type II isoform of steroid 5α-reductase (testosterone to DHT conversion is inhibited) in urogenital tissues
- Used to treat BPH – Benign Prostate Hyperplasia – 5mg qd used indefinitely (after 6 months check to see if its working) (Proscar®)
- Used to treat early male pattern baldness in men (1mg –Propecia®)
- Adverse Effects: may cause abnormal (male) fetal development
4
Q
What are the characteristics of Dutasteride (Avodart)?
A
- Is an inhibitor of both Type I and Type II 5α-reductase
- Is more potent than Finasteride leading to a greater reduction in DHT (90% after two weeks dosing and 93% in two years)
- Type II 5α-reductase : primarily active in reproductive tissues and responsible for 2/3 of circulating DHT
- Type I 5α-reductase : more active in liver,bone, and skin
- Side Effects : same as Finasteride
- Uses : BPH
5
Q
What are the characteristics of Ketoconazole (Nizoral)?
A
- Antifungal agent that blocks multiple P450-dependent steps in androgen and glucocorticoid synthesis
- Can be used in treatment of precocious puberty, hirsutism, prostatic carcinoma
- DOC for treatment of Cushing Syndromes
6
Q
What are the characteristics of Cimetidine (Tagamet)?
A
- Weakly blocks the androgen receptor
