Reproductive System & Sexual Health >
Combined Hormonal Contraception

“Combination of synthetic progestogen and oestrogen”

Method of Action
  • Combination of synthetic progestogen (progestin) and oestrogen (oestradiol valerate- prodrug or ethinyloestradiol)
    • Low oestrogen conc and high progesterone suppress gonadotrophin release
      • Gonadotrophin is responsible for follicular releasing hormone and luteinising hormone release from anterior pituitary
    • Progestins bind to progesterone receptors
      • Induce thick viscid mucous and inhibit LH surge
      • Bind to other receptors e.g. gonadotrophin, androgen, oestrogen, glucocorticoid and mineralocorticoid
        • Anti-gonadotrophin binding is desirable
        • Other receptor binding produces S/E
    • Synthetic oestrogen allows better cycle control and bleeding profile by stabilising endometrium, inhibiting FSH release
Effects
  • Fallopian tube
    • Reduced cilia beating, contractions
  • Ant pituitary and hypothalamus
    • Progestin inhibits LH surge
    • Oestrogen inhibits FSH release
    • Both: inhibit GnRH release
  • Endometrium
    • Thick viscid mucous induction
    • Increase PR receptors
    • Asynchronous development
  • Cervix
    • Progestin causes the thick viscid mucous plug
  • Ovary
    • Progestin stops ovulation
    • Oestrogen stops follicular development
Side Effects
  • Blood vessels: ↑­ clotting and ↓ antithrombin so ­↑ risk of MI/stroke/DVT
  • CNS: nausea, mood changes
  • Water and sodium retention: oedema, weight gain, breast tenderness
  • Hypertension
  • Androgenic effects: oily skin, acne, hirsutism, weight gain
  • Possible association with breast cancer in short term
Examples
  • COCP
    • Monophasic e.g. Zoely 24 days active, 4 days placebo
    • Biphasic, triphasic and quadriphasic e.g. Qlaria preparations
  • CTP: Evra patch weekly then patch free week, release hormones every 24hrs
  • Combined vaginal ring: NuvaRing stays in situ for 3 weeks
Contraindications
  • CVD
  • Obesity
  • >35
  • Smoking
  • Migraines
  • Liver disease
  • Breast cancer
Protection
  • Ovarian
  • Endometrial and colorectal cancer
Other Uses
  • Reduce menstrual symptoms
  • Menorrhagia
  • Acne

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