Combined Transdermal Patch (CPT) 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 CPT
A
- CPT 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.
- CPT 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 CPT?
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 CPT?
A
Apply a patch on the same day each week for 3 consecutive weeks (days 1, 8, and 15), have a patch-free interval on week 4 (days 22–28), then start a new cycle.
5
Q
What are the health benefits of CPT?
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.
6
Q
What are the side effects of CPT?
A
- Nausea and abdominal pain
- Headache
- Breast pain and/or tenderness
- Mood swings
- Minor skin irritation at the site of application
7
Q
What are the risks of CPT?
A
- Cardiovascular disease and stroke
- Hypertension and myocardial infarction
- Venous thromboembolism
- Breast cancer
- Cervical cancer
8
Q
What are the contra-indications of CPT?
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
9
Q
What is the guidance of vomiting or diarrhoea on CPT?
A
- Vomiting and diarrhoea do not affect the bioavailability of the CPT
- No additional contraception (such as condoms) are needed if a woman vomits or has diarrhoea whilst using the CPT
10
Q
Briefly describe how to assess a woman for CPT
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
11
Q
What is the efficacy of CPT?
A
- When the CPT is used perfectly→ 0.3% of women will conceive within the first year of use due to method failure
- When the CPT is used typically→ 9% will conceive within the first year of use due to method failure or user failure
12
Q
What are the advantages of CPT?
A
- The patch is applied once weekly, so is more convenient than taking a pill every day
- Patches do not become less effective if the user vomits or has diarrhoea→ hormones are absorbed through the skin, not through the gastrointestinal tract
- The patch is as effective as combined oral contraceptives (COCs) at preventing pregnancy
13
Q
What are the disadvantages of CPT?
A
- It can be seen
- It may become detached (partially or fully) from the skin, compromising efficacy
- It is less effective in women who weigh more than 90 kg
- Risks and adverse effects, such as skin irritation, nausea and vomiting, and unscheduled bleeding may occur
- There may be a delay in return to normal fertility after stopping the patch
