Wk 11: Contraception in practice: Combined hormonal contraceptives

Question 1

What is the mechanism of action of the CHC’s?

Answer 1

• suppress LH + FSH production, inhibiting ovulation
• Inc cervical mucus
• Thins endothelium reducing implantation

Question 2

How does CHC’s effect the endometrium?

Answer 2

• Oestrogen causes endometrium to proliferate + grow
• Progestogen prevents hyperplasia
• Resulting endometrium: thin, fragile + prone to bleeding

Question 3

Give an example of a biphasic COC

Answer 3

Binovum

Question 4

Give an example of a triphasic COC

Answer 4

Trinordiol

Question 5

Qlaira

Answer 5

• Quadriphasic pill for heavy menstrual bleeding
• Start day 1 - 28 tabs
• Missed pill rule differ

Question 6

Dianette

Answer 6

• Co-cyprindiol- cyproterone acetate + ethinylestradiol 2000/35
• Used for oral contraception + suffering from acne/hirsutism
• Inc risk venous thromboembolism

Question 7

Monophasic COC initiation: Day 1 upto + including day 5 menstrual cycle

Answer 7

• No additional contraception

- Start day 1

Question 8

Monophasic COC initiation: Day 6 of menstrual cycle onwards

Answer 8

• Additional precautions for 7 days after starting

- 9 qlaira

Question 9

Monophasic COC initiation: Postpartum

Answer 9

• Upto + including day 21 postpartum

- If not breast feeding + no VTE risk

Question 10

Monophasic COC initiation: termination/miscarriage

Answer 10

Immediately after or upto day 5

Question 11

What is the action to take when one pill is late <24 hrs but <48hrs?

Answer 11

• Take late/missed pill asap
• Continue taking remaining pill at usual time
• No additional protection needed

Question 12

What is the action to take when 2/more consecutive pills have been missed >48hrs?

Answer 12

• Take recent missed pill ASAP, any other missed = discarded
• Continue taking remaining pill at usual time
• Use additional contraception/avoid for 7 consecutive days: start continuously if runs btw HFI

Question 13

What are the actions to take when on short term (<2 months) treatment for enzyme inducing antibiotics?

Answer 13

• Use alt barrier method whilst taking + 28 days after stopping
• Break through bleeding can occur

Question 14

What are the actions to take when on long term (>2 months) treatment for enzyme inducing antibiotics?

Answer 14

Change alt method of contraception

Question 15

Interactions

Answer 15

• Antiepileptics
• Lamotrigine
• Johns wort

Question 16

What happens if vomiting occurs w/in 3 hrs of taking the pill?

Answer 16

Take another asap

Question 17

What is the advise if vomiting/severe diarrhoea occurs for >24 hrs?

Answer 17

• Follow instruction for missed pill, each day of V/D = missed pill
• Avoid intercourse/barrier during illness + 7 days after
• If illness occurs last 7 tabs, omit pill free period + start next cycle

Question 18

Outline the risks of age when taking COC

Answer 18

• Over 35 AND smoker

- Avoid >50 unless no risk factors

Question 19

What are the contraindications of COC?

Answer 19

UKMEC category 4:

• VTE
• Migraine w/ aura
• Smoker ≥15 cigs per day + ≥35 years

Question 20

What are some unwanted effects of COC?

Answer 20

• Tender breasts
• Headache
• Nausea
• Break through bleeding
• Weight gain
• Mood changes

Question 21

Which UKMEC is migraine w/ aura?

Answer 21

4 - contraindicated

Question 22

Which UKMEC is migraine w/o aura at initiation?

Answer 22

2

Question 23

Which UKMEC is new onset of migraine w/o aura after initiation?

Answer 23

3

Question 24

Outline the detached patch rules

Answer 24

Evra

• Partly detached <48hrs: re-apply patch
• Patch detached > 48hrs or not sure when detached: start new cycle (week 1 of day 1) + abstain/barrier for 7 days