Reproductive Pharms Flashcards
GnRH/FSH/LH analogues
- Uses
o Treatment of fertility disorders
o Increased reprodictive success - A single high dose of GnRH will stimulate FSH and LH release from the anterior pituitary
- Slow continuous release of GnRH causes down-regulation of receptors on the anterior pituitary and inhibition of FSH and LH release
GnRH analogues
- Buserelin
- Gonadorelin
o Anoestrus
o Ovarian dysfunction
o Cystic ovarian disease
o Oestrus synchronization
o Improved conception
Deslorelin
- Chemical castration: suppress reproductive axis in male dogs and ferrets, lionesses, kangaroos (extra-label in wildlife)
Synthetic GnRH analogues (Improvac)
o Suppresses boar taint
o Male antelope contraceptive
Chrono-gest)
- Used in ovines/caprines
- Females: induction of ovulation
Testosterone
- Androgenic (male characteristics) and anabolic (protein building)
- Testosterone is essential for development of the male reproductive tract, muscle and bone and RBC formation
- Lipid soluble, high first-pass effect
- Not really effective for increasing libido – tends to cause infertility!
- No vet products in SA for small animals and horses (Synovex contains testosterone for heifers)
- Testosterone Uses
o In female dogs: treating androgen sensitive carcinomas (mammary)
o In male dogs: urinary incontinence, rare forms of symmetrical alopecia, mammary tumours
o In cattle; for oestrus detectors and growth promotion
o Anabolic effect in chronic debilitating conditions
o Improvement of renal function in chronic interstitial nephritis
- Testosterone Side Effects
o Infertility
o Perianal adenomas
o Prostatic disorders
Anabolic Steroids
- Derivatives of testosterone
- Androgenic hormonal activity has been reduced relative to the tissue building activity
- Anabolic actions include
> Protein anabolism, increased muscle mass, Ca and P retention
> Increase erythrocyte development in bone marrow - No veterinary products currently available in SA for small animals and horses
- Nandrolone, Boldenone available overseas
- For cattle there is trenbolone acetate
- Anabolic steroids Clinical uses:
o Growth promoting in feedlot cattle
- Promotes growth, feed efficacy, lean carcass formation
o For geriatrics; recovery of chronic debilitating conditions
o Improvement of post-surgical wound healing
o Counter catabolic action of glucocorticoids
o Improve renal function in chronic interstitial nephritis
o Counter effects of hypoplastic anemia
o Treatment of androgen sensitive carcinomas
- Anabolic Steroids Side effects
o Heptatotoxicity in humans o Masculinization of females o Electrolyte and water retention o Infertility/impotence o Teratogenicity o Premature closure of growth plates o Prostatic hypertrophy Don’t use if there is pre-existing prostate pathology
- Oestrogens Sources
o Natural oestrogen
In most species; estradiol-17B, estrone and estriol
Estradiol-17B secreted by the ovary; converted into estrone and estriol during liver metabolism
The adrenal cortex and corpus luteum produce some oestrogen
In late pregnancy large quantities of oestrogen are produced by the placenta
o Plant oestrogens e.g. subterranean clover (Trifolium spp)
o Synthetic oestrogen
- Oestrogens Disposition
o Well absorbed from mucous membranes, GIT and injection sites
o Natural oestrogen has a high first-pass effect
o Very high plasma binding (natural oestrogens; sex-hormone binding globulin)
o Widely distributed, including the CNS
o Metabolized in the liver
- Oestrogens Clinical Uses
o Treatment of urinary incontinence; oestriol
- Indicated for spayed bitches > 1 year of age
- Improves functioning of urethral sphincter
o Growth stimulant in feedlot animals (anabolic effects)
o Treatment of perianal adenomata, prostatic hypertrophy (including some prostatic tumours), testicular tumours and some mammary tumours
o Treat endometritis; endothelium-protective
o For misalliance; oestrogen prevents implantation and prolongs oestrus
o Treatment of pseudopregnancy (cabergoline or spaying give better and safer results)
- Oestrogens Side effects
o Bone marrow dyscrasia; lethal if overdosed in dogs o Fatty changes in the liver (dogs) o Iatrogenic pyometra secondary to Cystic Endometrial Hyperplasia (CEH) o Mammary neoplasia o Prolonged oestrus o Vaginal prolapse in ewes o Follicular cysts o Decreased milk release
- Oestrogens Veterinary Formulations
o Oestriol
- Urinary incontinence in female spayed dogs
o Oestradiol
- Growth promoter often together with progesterone or testosterone in ear implants
- Has anabolic effects
o Zeranol
- Oestrogen-like effects used for growth promotion
Progesterones and Progestagens
- Progestogens are synthetically produced and have similar actions as progesterones, produced by the CL for the maintenance of pregnancy.
- Overall, they inhibit the release of gonadotrophin releasing hormone (GnRH). Oestrus prevention!
- Progesterone is the hormone responsible for maintenance of pregnancy and mostly produced mostly by the corpus luteum, then smaller amounts from the placenta and adrenals.
- Progesterone increases endometrial gland growth and secretions and causes mammary alveoli development.
- Progesterone also some anabolic effects and behavioural effects.
- Progesterone and progestagens Clinical Uses
o Oestrus synchronization and anoestrous in sheep and cattle
o Physiological concentrations help maintain pregnancy in case of threatening abortion
o High concentrations prevents implantation and decidualisation (cellular changes of endometrium that allows placenta formation)
o Used for treatment of military dermatitis in cats
o Behavioural problems
Urine spraying (cats)
Aggression
o Non-specific anabolic effect and appetite stimulant
o Prostatic hyperplasia, vaginal hyperplasia, pseudopregnancy
o Inhibition of oestrus cycle in small animals (AVOID!)
- Progesterone and progestagens Side effects
o Local skin/tissue reaction at site of injection
o Weight gain (polyphagia), PU/PD
o Anabolic and renal effects
o Diabetes mellitus (Insulin resistance)
o Atrophy of the adrenal gland don’t combine with corticosteroids
o Cystic endometrial hyperplasia, possibly leading to pyometra – don’t use to prevent heat in cats and dogs
o Hyperplasia, milk secretion and a probable increase incidence of mammary tumors
- Progesterone and progestagens Veterinary formulations
o Progesterone - Heifers and cows o Flugestone - Ewes o Altrenogest - Gilts, - Oral o Norgestomet and estradiol valerate o Proligestone - Suppress or postpone oestrus in dogs - Can cause prolonged anoestrus - Risk of causing pyometra - Used to treat miliary dermatitis in cats o Melengesterol acetate - Growth promoter in cattle
- Progesterone and progestagens Old formulations
o Megesterol acetate (Ovarid®)
o Suppress oestrus in bitches
o Treat vaginal hyperplasia and pseudopregnancy in bitches
o To control unacceptable male behavior
o In cats to treat various progestin-responsive dermatological problems
- Medroxyprogesterone acetate
- Medroxyprogesterone acetate
o Suppress oestrus in bitches
o treat certain behavioral disorders such as aggression and male cat spraying
o treat dermatological disorders
Aglepristone
- Oestrogens historically used for misalliance → swelling of the fallopian tube
- Aglepristone is a safer, more effective abortifacient in cats, dogs and rabbits
- Has a higher affinity for uterine receptors than endogenous progesterone
- Effective for up to 45 days after mating
o Prevents implantation in early pregnancy
o Abortogenic in later pregnancy - Used extra-labelly for pyometra treatment and inducing parturition (dogs)
- Two SC injections, 24hrs apart (be precise with timing)
o Abortion within 4 days after treatment
Prostaglandins F alpha two Clinical uses
oCattle and sheep (latter extra-label)
Oestrous synchronization
Abortifacient (C:1 st 5 months, S: duration)
Induction of parturition (C: last 2 weeks)
Treat luteal cysts (C)
Treating pyometra and foetal mummification
Silent heat or subclinical oestrous (C)
oPigs Induction of parturition o Horses Pyometra Oestrous synchronization; improves breeding efficiency Abortifacient
oDogs and cats (extra-label)
Abortifacient
Cystic endometrial hyperplasia/pyometra complex
