Oestrogens and progestogens: combined ethinylestradiol products, desogestrel

Question 1

Oestrogens and progestogens: combined ethinylestradiol products, desogestrel

Common Indications

Answer 1

• For hormonal contraception in women who require highly effective and reversible contraception, particularly if they may also benefit from its other effects, such as improved acne symptoms with oestrogens.
• For hormone replacement therapy (HRT) in women with early menopause (when it is given until 50 years of age) and those who have distressing menopausal symptoms.

Question 2

Oestrogens and progestogens: combined ethinylestradiol products, desogestrel

Mode of Action

Answer 2

• Luteinising hormone (LH) and follicle-stimulating hormone (FSH) control ovulation and ovarian production of oestrogen and progesterone.
• In turn, oestrogen and progesterone exert predominantly negative feedback on LH and FSH release.
• In hormonal contraception, an oestrogen (e.g. ethinylestradiol) and/or a progestogen (e.g. desogestrel) are given to suppress LH/FSH release and hence ovulation.
• Oestrogens and progestogens also have many effects outside the ovary. Some, such as those on the cervix and endometrium, may contribute to their contraceptive effect (this is especially important in progestogen-only contraception).
• Others offer additional benefits, e.g. reduced menstrual pain and bleeding, and improvements in acne.
• At the menopause, a fall in oestrogen and progesterone levels may generate a variety of symptoms, including vaginal dryness and vasomotor instability (‘hot flushes’).
• Oestrogen replacement (usually with a progestogen) alleviates these.

Question 3

Oestrogens and progestogens: combined ethinylestradiol products, desogestrel

Adverse Effects

Answer 3

• Irregular bleeding and mood changes.
• double the risk of venous thromboembolism (VTE),
• risk of cardiovascular disease and stroke
• effects of hormone replacement therapy similar to those of CHC but, as the baseline rates are higher, the relative risks have more significant implications.increased risk of breast and cervical cancer

Question 4

Oestrogens and progestogens: combined ethinylestradiol products, desogestrel

Warnings

Answer 4

• All forms of oestrogens and progestogens are contraindicated in patients with breast cancer.
• Combined hormonal contraception should be avoided in patients at increased risk for VTE (past VTE; known thrombogenic mutation) or cardiovascular disease (age >35 years; cardiovascular risk factors; migraine with aura; heavy smoking history).
• Concurrent use of cytochrome P450 inducers (e.g. rifampicin) may reduce the efficacy of hormonal contraception, particularly progestogen-only forms. Most other antibiotics are safe to use with hormonal contraception.

Question 5

Oestrogens and progestogens: combined ethinylestradiol products, desogestrel

Administration

Answer 5

• COC pills can be started on any day of the cycle.
• If this is within the first 6 days, no additional contraception is needed.
• If it is beyond day 6, a barrier method should be used or sex avoided for the first 7 days.
• Most combined pills are designed to be taken for 21 days followed by a 7-day pill-free interval, during which a withdrawal bleed occurs.
• Some (‘everyday’) pills are taken throughout the cycle, but the tablets for days 22–28 are inactive.