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Flashcards in Oral contraceptives Deck (17):

Where are oestradiol and progesterone released from?



Adrenal cortex



List the three types of oral contraceptives?

Combined preparations

Sequential preparations

Progesterone-only oral preparations (mini-pill)



Which hormones are usually found in oral contraceptives?

Oestrogens: ethinyloestradiol (most are synthetic)

Progestogens: levonorgestrel, cyproterone, drospirenone


Describe the use of cyproterone in oral contraceptives?

New progestogen

Highest venous thromboembolic risk

Antiandrogenic activity (PCOS)

Taken off the market in some countries 


Describe the use of drospirenone in oral contraceptives?


Derived from spirinolactone



Describe the mechanism of action of oral contraceptives?

Oestrogen inhibits FSH (maybe LH)

Progestogen can work in some cycles to have negative feedback on LH
Also makes endometrium unfavourable for implantation, mucous inhospitable tio sperm and interferes with coordinated contractions of reproductive system that facilitate conception 


Which of the oral contraceptives must be taken at the same time everyday? 

Sequential preparations and progestogen-only preparations


Describe the sequential preparation oral contraceptives?

Ratio of doses of oestrogen and progestogen varies to correspond approximately to changes in endogenous levels

Reduces side effects


Describe the use of progestogen-only oral preparations as oral contraceptives?

Used when oestrogens are contraindicated

Least effective

Can be used by lactating women


Why is the progestogen-only oral preparation the only suitable oral contraptive for lactating women?

Oestrogen inhibits lactation 


Describe the adverse effects associated with combined oral contraceptives?

Hypertension (small and reversible in healthy individuals)

Venous thromboembolism increased risk

Possible increased risk of breast, cervical and uterine cancer

Other: nausea, vomiting, weight gain etc.

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Describe the risk of VTE that is associated with use of COCs?

Increased risk

Associated with dose of oestrogen, the progestogen and presence of other risk factors

Most apparent risk in women over 35 who smoke

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Describe the association between COCs and endometrial cancer?

Increased incidence of endometrial carcinoma associated with oestrogen administration

When progestogen given concurrently to woman with intact uterus > protective effect 


List the benefits of COCs?

Decreased risk of endometrial cancer
Decreased incidence of ovarian cancer and ovarian cyst formation
Reduction in risk of colorectal cancer
Protective effect on benign breast tumours
Reduction in risk of bone fractures
Reduction in dysmenorrhea and menorrhagia > protection against iron deficieny anaemia


Describe the use of vaginal rings as contraceptives?

Etonogestrel (progestogen) and ethinyloestradiol (oestrogen)

Inserted into vagina for 3 weeks, removed for one week

Low dose (bypasses portal circulation)


Describe the use of progestogen-only contraceptives?

IM injections every 12 weeks

Subdermal implants (effective up to 3 years)

IUD (effective up to 5 years)


Describe emergency contraception?

Morning-after pill

One tablet of 1500ug levonorgestrel (progestogen)

Within 72 hours unpritected sex