5.2.2 Oral Contraceptives Flashcards
(41 cards)
What enzymes metabolise COCP and POP?
CYP450 in liver
What can affect COCP and POP contraceptives?
Efficacy is affected by enzyme inducing drugs which stimulate CYP450, therefore more breakdown of contraceptives
What drugs cannot be taken at the same time as COCP and POP?
Anti-epileptics
Carbamazepine or phenytoin
Antibiotics
Rifampicin and rifabutin
St John’s Wort
All increase production of CYP450
What natural products can enhance oestrogen absorption?
Soya protein
Enhances oestrogen absorption and reduces its storage in adipose and muscle
Half life reduced from 15 hours to 7 hours
What is the combined oral contraceptive pill (COCP)?
Pill containing synthetic oestrogen and progesterone
How long is the COCP taken for?
21 days with a 7 day break
What does the COCP do?
Prevents ovulation
Reduces endometrial receptiveness to implantation
Thickens cervical mucus
What are the adverse effects of the COCP?
Increased risk of:
- VTE
- Stroke
- Breast cancer
- Cervical cancer
What are the contraindications of the COCP?
- Smoker
- Previous VTE
- High BMI
- Hypertension
- IHD/stroke
- Migraine
- Breast cancer
- Cirrhosis
Basically, things that put you at higher risk of clots, more oestrogen so breast cancer, cirrhosis as impaired oestrogen break down
What does the progestogen-only pill do?
Thickens cervical mucus
Reduced cilia activity in fallopian tubes
OVULATION IS NOT PREVENTED
Contains low-dose progestogen, taken daily with NO breaks
What are the advantages of the POP?
99% reliability
Can be used if COCP cannot
What are the disadvantages of the COCP?
No STI protection
Strict timing- user dependant
Menstrual irregularities
Increased risk of ectopic pregnancy (due to immotile cilia)
When is hormone replacement therapy offered?
Vasomotor or mood disorders
Urogenital symptoms
How is HRT given?
Oral or transdermal
Combined oestrogen and progesterone if woman has a uterus
Oestrogen alone if there is no uterus
Progesterone protects the endometrium from hyperplasia
What is the first line treatment for urogenital symptoms?
Low-dose vaginal oestrogen
What types of oestrogens are used in HRT?
Natural oestrogens
e.g. oestradiol
What types of progesterones are used in HRT?
Progesterone analogues
Testosterone analogues
Bioidentical- less side effects and risks
What are the risks of using HRT?
Endometrial cancer (if oestrogen is unopposed)
Breast cancer
VTE- oral only
Stroke- oral only
CHD- if before 60
Explain how HRT increases the risk of VTE
Increased:
- Activated protein C resistance
- Thrombin activation
Decreased:
- Anti-thrombin III activity
- Protein S levels
- Factor VII levels
- Tissue factor pathway inhibitor
What is used to treat osteoporosis?
Bisphosphonates
How do bisphophonates work?
Reduce bone turnover by controlling osteoclast activity
When are bisphophonates used?
Prophylaxis and treatment of osteoporosis
Management of other diseases involving bone e.g. Paget’s disease of bone, malignancy
Identify the pharmacokinetics of bisphophonates
Long half life
Poor gut absorption
Absorption affected by food, needs to be taken on an empty stomach
What adverse reactions can occur when taking bisphophonates?
Upper GI effects
Oesophagitis- remain seated of standing for 30 minutes after taking
Hypocalcaemia
Check calcium and vitamin D levels prior to treatment
