CHC Flashcards
Benefits of CHC
- Can use from menarche to age 50
- bleed control
- different routes: oral/patch/vaginal ring
- reversible and convenient
- reduces menstrual loss by 40%
- reduces dysmenorrhoea/relieves ovulation pain
- improves acne/hirsutism
- may improve PMS
- protects against ectopics
- reduces risk of ovarian and endometrial ca
Disadvantages of CHC
- user error
- drug interactions
- no protection against STIs
- increased risk of cervical and breast ca
- increased risk of clots (PE/DVT/MI/Stroke)
CHC is definitely NOT suitable for those who…
- have migraine with aura
- have current/recent breast ca
- are currently breastfeeding and <6 weeks post partum
- those <3 weeks post partum or <6 weeks post partum with other risk factors for VTE (immobility, transfusion at delivery, BMI >30, PPH, C-section, pre-eclampsia, smoking)
- who have BMI >35
- have HTN
- are >35 years and smoke >15 cigs/day
- have multiple risk factors for CVD
- have current or past VTE, or VTE in 1st degree relative <45 years, or known thrombogenic mutation
- have BRCA gene
- are diabetic with end organ damage
- have had bariatric surgery
- are immobilised for prolonged time post surgery
- have acute or flare of viral hepatitis
- have cirrhosis/liver ca
- have current/past IHD
- have hx of stroke
- have antiphospholipid antibodies
What is the mechanism of action of CHC?
- Main mode: prevention of ovulation via negative feedback, by suppressing LH and FSH
- thickening of cervical mucus
- suppression of endometrial growth
What is the efficacy of CHC?
- with perfect use, 3 in 1000 women get pregnant
- with typical use, 9 in 1000 women get pregnant
How would you explain to a patient the ‘standard’ method of taking COCP?
For most, a pill is taken daily for 21 days, followed by a 7 day pill break - during which a withdrawal bleed occurs.
How would you explain to a patient the ‘standard’ method of the patch?
a patch is changed every 7 days for 3 weeks, followed by a 7 day patch free week - during which a withdrawal bleed occurs
How would you explain to a patient the ‘standard’ method of the vaginal ring?
a ring is inserted into the vagina and remains in place for 3 weeks, followed by a 7 day ring free break - during which a withdrawal bleed occurs
How can you tailor (off licence) CHC use?
- you can have a shortened hormone free interval (21 days of hormones, then 4 day break) - protects better against pregnancy
- you can extend use (i.e. run pills back to back for 3 months, then have a 7 day or 4 day break) - to reduce withdrawal bleed frequency
- you can continuously use CHC and never have a hormone free interval - to prevent withdrawal bleeds altogether
- flexibly continuously using CHC until breakthrough bleed, then have hormone free interval for 4 or 7 days
“I vomited after taking the COCP. What should I do?”
- If vomited within 2 hours of COCP, another pill should be taken, no further action needed
- If vomiting continuously or having profuse diarrhoea, should use missed pills rules
Name some liver enzyme drugs
CRAP GPs:
- Carbemazepine
- Rifampicin
- Alcohol
- Phenytoin
- Griseofulvin
- Phenobarbitone
- Sulphonylureas
Which anti-epileptic medication is not recommended for concomitant use with CHC?
Lamotrigine! CHC can reduce serum levels of lamotrigine and therefore increase seizure frequency during its use, then risk toxicity in the hormone free period
How long after taking UPA-EC can I commence CHC?
5 days
When should CHC be stopped and restarted if having major elective surgery?
CHC should be stopped 4 weeks prior to surgery and restarted 2 weeks after full mobilisation
How long is fertility delayed after stopping CHC?
There is no delay! conception rate is 79.4-95% within 12 months of ceasing CHC use
