CHC: FSRH 2011

Question 1

How does combined hormonal contraception (CHC) work?

Answer 1

• Inform: bleed experienced in HFI/placebo week odue to withdrawal of hormones rather than menstruation.
• May wish advise about use of extended or continuous regimens of CHC but should be aware that such use is off licence.

Question 2

CHC efficacy

Answer 2

inform: efficacy of all CHCs is generally similar

Question 3

Initial assessments for CHC

Answer 3

• detailed history ifrequesting CHC & recheck history at least annually. should include
• • medical conditions such as migraine,
• • drug use,
• • family medical history, and
• • lifestyle factors such as smoking.
• BP document, prior to first prescription of CHC.
• BMI document, prior to first prescription of CHC.

Question 4

Drug interactions & CHC

antibiotics not induce enzymes.

Answer 4

• Additional contraceptive not required

Question 5

Drug interactions & CHC

short-term enzyme-inducing drug

Answer 5

• not wish to change, may continue COC of at least 30 µg EE, patch or ring along with additional contraception. - An extended or tricycling regimen should be used and HFI shortened to 4 days.
• Additional contraception should be continued for 28 days after stopping the enzyme-inducing drug.

Question 6

Drug interactions & CHC

enzyme-inducing drug (exception of the very potent enzyme inducers rifampicin and rifabutin)

Answer 6

• not wish to change from COC or use additional precautions may increase the dose of COC to at least 50 µg EE (maximum 70 µg EE) and
• use an extended or tricycling regimen with a pill-free interval of 4 days.

Question 7

Drug interactions & CHC

lamotrigine (except in combination with sodium valproate)

Answer 7

Advise risks of using CHC may outweigh benefits.:

• due to risk of reduced seizure control whilst on CHC,
• potential for toxicity in CHC-free week,

Question 8

Drug interactions & CHC
ulipristal acetate (UPA)

Answer 8

• Advise: UPA, potential to reduce the efficacy of hormonal contraception.
• Additional precautions for 14 days after taking UPA (9 days if using or starting the progestogen-only pill, 16 days for the estradiol valerate/dienogest pill) (outside product licence).

Question 9

CHC whilst travelling or at high altitude

Answer 9

• advise: Reducing periods of immobility during
  flights over 3 hours.
  Women trekking to altitudes of >4500 m for periods of more than 1 week may be
  advised to consider switching to an alternative method.

Question 10

CHC: trekking to altitudes of >4500 m for periods of more than 1 week

Answer 10

advise: consider switching to an alternative method.

Question 11

CHC & non-contraceptive health benefits.
acne.
colorectal cancer
menstrual pain and bleeding.
menopausal symptoms.
expected bleeding patterns

Answer 11

• may help to improve acne.
• Reduction in the risk of colorectal cancer and this may also apply to other CHCs.
• may help to reduce menstrual pain and bleeding.
• may reduce menopausal symptoms.
• Before starting advise about expected bleeding patterns both initially and in the longer term.

Question 12

CHC & VTE

how much the risk

Answer 12

• compared to non-users, risk of VTE with use of CHC is approximately doubled but absolute risk is still very low.

Question 13

CHC & VTE

Thrombophillia screen

Answer 13

• For women with a family history of VTE, a negative thrombophilia screen does not necessarily exclude all thrombogenic mutations.
• A thrombophilia screen is not recommended routinely before prescribing CHC.

Question 14

CHC & VTE

personal history of VTE or a known thrombogenic mutation

Answer 14

unacceptable health risk if CHC is used.

Question 15

CHC & VTE

When prescribing considerations to

Answer 15

Be guided by

• individual’s own personal preference,
• risk of VTE,
• any contraindications,
• possible non-contraceptive benefits and
• experience with other contraceptive formulations.

Question 16

CHC & smoking

Answer 16

aged ≥35 years who smoke, use not recommended.

Question 17

CHC & ischaemic stroke associated

Answer 17

• may be a very small increase in the absolute risk of ischaemic stroke.

Question 18

CHC & BP

Answer 18

• risks in properly taken BP which is consistently elevated generally outweigh the advantages.
• Systolic BP ≥160 mmHg or diastolic BP ≥95 mmHg is a condition that represents an unacceptable health risk.

Question 19

CHC & BMI ≥35kg/m2

Answer 19

risk usually outweighs the benefits.

Question 20

CHC & Migraine with aura

Answer 20

unacceptable health risk.

Question 21

CHC & breast Cancer

Answer 21

• any risk associated likely to be small, and will reduce with time after stopping.

Question 22

CHC & cervical Cancer

Answer 22

• may be associated with a small increase in risk, which is related to duration of use.
• check if up to date with cervical cytology screening.

Question 23

CHC & overall mortality.

Answer 23

• not appear to have a negative effect.

Question 24

CHC & ovarian and endometrial cancer

Answer 24

Use of COC is associated with a reduced risk, that continues for several decades after stopping.

Question 25

CHC & mood changes, depression & weight gain.

unproven concerns.

Answer 25

• may be associated with mood changes but there is no evidence that it causes depression.
• current evidence does not support a causal association with weight gain.