Combined Oral Contraceptive Pill (COCP) Flashcards
1
Q
What are the 3 types of combined hormonal contraceptives (CHCs)?
A
Combined hormonal contraceptives (CHCs):
- Oral contraceptives
- Transdermal patch
- Vaginal ring
2
Q
Briefly describe the mechanism of action of COCP
A
- COCP act primarily to inhibit ovulation.
- Ovulation is inhibited by the oestrogen and progestogen components which act on the hypothalamo-pituitary axis to reduce production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). With no surge in LH and FSH to stimulate the ovaries, ovulation does not occur.
- COCP also have contraceptive effects on cervical mucus and the endometrium.
- The oestrogen component causes the endometrium to proliferate and grow.
- The progestogen component prevents hyperplasia of the endometrium by opposing the proliferative effects of oestrogen.
3
Q
What are the indications of COCP?
A
- Contraception
- Hyperandrogenism (e.g. acne, hirsutism)
- Menstrual cycle disorders (e.g. menorrhagia, dysmenorrhea)
- Symptom control in endometriosis and leiomyomas
4
Q
What is the most common regime to take COCP? And why is this?
A
- 28-day cycles, with 21 consecutive daily active pills followed by a 7-day hormone free interval (HFI) prior to starting the next packet of pills.
- The first seven pills inhibit ovulation and the remaining 14 pills maintain anovulation.
- Traditionally women have then either had seven pill-free days or taken seven placebo tablets; during this HFI, most women will have a withdrawal bleed due to endometrial shedding
5
Q
How many hours is the COCP considered to have been “missed”?
A
Missed if it is not taken in the 24 hours after it should have been taken.
6
Q
What are the health benefits of COCP?
A
- Reduced risk of ovarian, endometrial and colorectal cancer;
- Predictable bleeding patterns
- Reduced dysmenorrhoea and menorrhagia;
- Management of symptoms of polycystic ovary syndrome (PCOS), endometriosis and premenstrual syndrome;
- Improvement of acne;
- Reduced menopausal symptoms;
- Maintaining bone mineral density in peri-menopausal females under the age of 50 years.
7
Q
What are the side effects of COCP?
A
- Nausea and abdominal pain.
- Headache.
- Breast pain and/or tenderness.
- Mood swings.
- Menstrual irregularities.
8
Q
What are the risks of COCP?
A
- Cardiovascular disease and stroke
- Hypertension and myocardial infarction
- Venous thromboembolism
- Breast cancer
- Cervical cancer
9
Q
What are the contra-indications of COCP?
A
- BMI greater than 35
- Breast feeding
- Smoking over the age of 35
- Hypertension
- History of or family history of venous thromboembolisms
- Prolonged immobility due to surgery or disability
- Diabetes mellitus with complications e.g. retinopathy
- History of migraines with aura
- Breast cancer or primary liver tumours
10
Q
At what age would COCP not be appropriate to prescribe?
A
- >50 years non-smoker
- <35 years smoker
11
Q
What is the guidance on missed doses of COCP?
- If one pill is missed, anywhere in the pack (i.e. more than 24 and up to 48 hours late)
A
- The last pill missed should be taken now, even if it means taking two pills in one day.
- The rest of the pack should be taken as usual.
- No additional contraception is needed.
- The seven-day break is taken as normal.
12
Q
What is the guidance on missed doses of COCP?
- If two or more pills are missed (i.e. more than 48 hours late)
A
- The last pill missed should be taken now, even if it means taking two pills in one day.
- Any earlier missed pills should be left.
- The rest of the pack should be taken as usual and additional precautions (eg, condoms or abstinence) should be taken for the next seven days.
- The next step then depends on where in the packet the pills are missed:
- If the pills are missed in the first week of a pack (pills 1-7): emergency contraception should be considered if the patient had unprotected sex in the pill-free interval or the first week of the pill packet. She should finish the packet and have the usual pill-free interval.
- If the pills are missed in the second week of a pack (pills 8-14): there is no need for emergency contraception as long as the pills in the preceding seven days have been taken correctly. The packet should be finished and the usual pill-free interval taken.
- If the pills are missed in the third week of a pack (pills 15-21): the next pack of pills should be started without a break - ie the pill-free interval is omitted. If taking a packet with dummy/placebo pills, these should be discarded, and the new packet started. Emergency contraception is not required.
13
Q
What is the guidance of vomiting or diarrhoea on COCP?
A
- Vomiting within two hours of taking the pill, or very severe diarrhoea, can affect the absorption of the pill.
- A woman who vomits within two hours of taking a pill should ideally take another one as soon as possible.
- The advice for women who experience vomiting or diarrhoea for more than 24 hours is to follow the same advice as if they had missed pills.
14
Q
Briefly describe how to assess a woman for COCP
A
- Check the UK Medical Eligibility Criteria
- Enquire specifically about:
- Migraine
- Cardiovascular risk factors such as smoking, obesity, hypertension, previous venous thromboembolism, hyperlipidaemia and thrombophilia
- Past and current medical conditions
- Family history
15
Q
What is the efficacy of COCP?
A
- When the COCP is used perfectly→ 0.3% of women will conceive within the first year of use due to method failure
- When the COCP is used typically→ 9% will conceive within the first year of use due to method failure or user failure
