7. Main function
Preparation of uterus for nidation & maintenance of pregnancy
Uterus:
ď Secretary changes (in the oestrogen primed endometrium)
ď If ovum is fertilized
ď prepare endometrium
ď oxytocin & ergonovine actions
ď FSH, LH ovulation
ď Cervical secretion â thick, viscid, scanty
8. ďźVagina: induce pregnancy like changes, leucocyte infiltration
of cornified epithelium
ďźBreast: causes proliferation of acini, Act in concert with
estrogen, to prepare breast for lactation
ďźBody temperature: increased (0.50
C)
ďźRespiration: at higher dose stimulate
ďźPituitary: weak inhibitor of Gn secretion, Negative feedback
primarily at hypothalamus, reduce the frequency of GnRH
pulse
ďźMetabolism: impair glucose tolerance,
19-nortestosterone derivati: LDL and HDL
10. Classification by Generation
Classificatio
n by
structure
First Second Third
Estranes Ethynodiol
diacetate
â â
Norethindrone
Norethindrone
acetate
Gonanes Norgestrel Levonorgestrel Desogestrel
Gestodene
Norgestimate
Pregnanes Medroxyprogeste
rone acetate
â â
11. Natural progesterone
obtained from soybeans and Mexican yam roots, and
animal ovaries (often).
Progesterone derivatives (C-21 steroid structures)
ď§Hydroxyprogesterone caproate (i.m)
ď§Medroxyprogesterone Acetate (im,Oral)
ď§Megesterol Acetate (oral)
ď§Dydrogesterone (oral)
ď§Almost Pure progestins
ď§Weaker anti-ovulatory action
12. Nomegesterol (oral microionized natural progesterone)
ď§Weak antiandrogenic, Less anti-ovulatory, Strong
antioestrogenic
ď§Micronizing process increase the half-life of progesterone
and reduce its destruction in the GIT and Maxium serum
conc. achieved rapidly
ď§Absorption 2 fold increased when taken with food.
ď§No Adverse effects on mood, lipid profile, glucose
tolerance and pregnancy outcome
Common side effects: Fatigue and Sedation.
13. 19-Nor-testosterone derivative
Older Compounds
ď§ Norethindrone
ď§ Lynestrenol (Ethinyl
oestradiol)
ď§ Allylestrenol,
ď§ Additional weak oestrogenic,
androgenic and anabolic
ď§ potent anti-ovulatory actions
19-Nor-testosterone derivatives: (Gonanes)
Levonorgestrel, Desogestrel, Norgestimate, Gestodene
ď§ All are given orally
ď§ Very potent progestins,
ď§ No androgenic effects, Strong anti-ovulatory actions
ď§ Used in OCS
ď§ Do not antagonize the beneficial effects of estrogens on lipid
profile
ď§ Suitable for women with hyperandrogenemia
14. Synthetic Progestins (Except Gonanes) Vs Natural Progestins
Androgenic effects of synthetic progestins include
ďźfluid retention,
ďźreduction of HDL cholesterol levels,
ďźheadaches and
ďźmood disturbance.
ďSome of 19-nortestosterone are strongly
androgenic
ďźProducing hirsutism and acne
17. ⢠OCS: Minipill, Norplant, conventional OCS
⢠HRT â to antagonize oestrogen side effects, a progestin lacking
androgenic activity is preferred
⢠DUB: Adolescent, peri/Menopausal women, Norethindrone 20-40
mg/day promptly stops the bleeding, subsequent cyclic treatment with
estrogen
⢠Endometriosis: presence of ectopic endometrial cells outside
the uterus, continue to respond to O and P, cause dysmenorrhea, painful
pelvic swelling, infertility.
⢠Goal of therapy is to induce estrogen poor environment, Continued
admn. of P induces anovulatory, estrogenic poor state by GnRH
⢠Dysmenorrhea
Clinical uses of Progesterones
18. ⢠Premenstrual syndrome: suppress ovulation (O + P)
⢠Threatened abortion: only P deficiency cases: pure
P without androgenic and oestrogenic preferred
⢠Post-partum lactation
⢠Endometrial cancer: palliative, high dose required
⢠Hypoventilation
Clinical uses of Progesterones
20. Adverse effects of Progesterone
⢠breast engorgement, headache, rise in body
temp, oedema, acne & mood swings
⢠masculinization of external genitalia in the
foetus
⢠Increased incidences of congenital
abnormalities
⢠irregular bleeding or amenorrhea
⢠lower HDL (19-nortestosterone derivatives)
⢠hyperglycaemia
22. Pharmacokinetics
â˘Absorption:
⢠progesterone undergoes high first pass metabolism.
Therefore synthetic preparations are commonly used.
⢠Progesterone esters in oily soln. for i.m. admn.
â˘Metabolism:
⢠by liver enzymes
⢠excretion by urine after conjugation
26. Mifepristone
Mechanism:
⢠Partial agonist, progesterone receptor modulator
⢠During luteal phase: Block Pregest. PGs Uterine
contraction
⢠Sensitize myocardium to PGs. Induce menstruation
⢠HCG production falls, secondary luteolysis, softening of cervix
leading to abortion
ADME:
⢠F: 25 %, CYP3A4 metabolism, t½: 20 h
27. Uses:
⢠Termination of early pregnancy â along with
prostaglandin (upto 7 weeks), 600 mg single oral + 400 mg
oral misoprotol or 1mg gemeprost intravaginally
⢠As a cervical ripening agent: surgical abortion
⢠Post-coital contraceptive: within 72 hours
⢠Once a month contraceptive: 200 mg at 2 days after
midcycle of ovulation
⢠Progesterone sensitive tumors
⢠Cushingâs syndrome
28. Side effects:
ďźVomiting, diarrhoea,
ďźpelvic pain or abdominal pain,
ďźabout 5% have severe vaginal bleeding
Precaution: Not to be given to a woman with suspected
ectopic pregnancy, hematological disorders, receiving oral
anticoagulants, Liver/renal diseases
29. Ulipristal
⢠Selective progesterone receptor modulator (SPRM)
⢠Used in emergency contraceptive (within 5 days, 30 mg)
⢠Inhibits ovulation by LH surge + direct effect on follicule
⢠By its action on endometrium, inhibits implantation
⢠Weaker anti-glucocorticoid activity
⢠Metabolised by CYP3A4 and drug interaction possible with
rifampicin, phenytoin, carbamazepine
OTHERS:
ďąOnapristone (pure progesterone antagonist) ,
ďąGestinone (more effective in endometriosis)