Combined hormonal contraceptives 439

7.3.1 Combined hormonal contraceptives 439

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The effectiveness of contraceptive patches can also be reduced by drugs that induce hepatic enzyme activity. Additional contraceptive precautions are required whilst taking the enzyme-inducing drug and for 4 weeks after stopping. If concomitant administration runs beyond the 3 weeks of patch treatment, a new treatment cycle should be started immediately without a patch-free break. For women taking enzyme-inducing drugs over a long period, another method of contra- ception should be considered.

Some antibacterials that do not induce liver enzymes (e.g. ampicillin, doxycycline) may reduce the efficacy of combined oral contraceptives by impairing the bacterial flora responsible for recycling ethinylestradiol from the large bowel. Additional contraceptive precautions should be taken whilst taking a short course of an antibacterial drug that is not enzyme-inducing and for

7 days after stopping. If these 7 days run beyond the end of a packet the next packet should be started immedi- ately without a break (in the case of ED tablets the inactive ones should be omitted). If the antibacterial course exceeds 3 weeks, the bacterial flora develop anti- bacterial resistance and additional precautions become unnecessary unless a new antibacterial is prescribed; additional precautions are also unnecessary if a woman starting a combined oral contraceptive has been on a course of antibacterial therapy for 3 weeks or more.

It is possible that some antibacterials affect the efficacy of contraceptive patches. Additional contraceptive pre- cautions are recommended during concomitant use and for 7 days after discontinuation of an antibacterial that is not enzyme-inducing (except tetracycline). If concomi- tant administration runs beyond the 3 weeks of patch treatment, a new treatment cycle should be started immediately without a patch-free break. If the anti- bacterial course exceeds 3 weeks, additional precau- tions become unnecessary unless a new antibacterial is prescribed; additional precautions are also unnecessary if a woman starting a contraceptive patch has been on a course of antibacterial therapy for 3 weeks or more.

Surgery Oestrogen-containing contraceptives should preferably be discontinued (and adequate alternative contraceptive arrangements made) 4 weeks before major elective surgery and all surgery to the legs or surgery which involves prolonged immobilisation of a lower limb; they should normally be recommenced at the first menses occurring at least 2 weeks after full mobilisation. A depot injection of a progestogen-only contraceptive may be offered and the oestrogen-con- taining contraceptive restarted later—if preferred before the next injection would be due. When discontinuation of an oestrogen-containing contraceptive is not possi- ble, e.g. after trauma or if a patient admitted for an elective procedure is still on an oestrogen-containing contraceptive, thromboprophylaxis (with heparin and graduated compression hosiery) is advised. These recommendations do not apply to minor surgery with short duration of anaesthesia, e.g. laparoscopic sterilisa- tion or tooth extraction, or to women using oestrogen-

free hormonal contraceptives (whether by mouth or by injection).

Reason to stop immediately Combined hormonal contraceptives or hormone replacement therapy (HRT) should be stopped (pending investigation and treat- ment), if any of the following occur:

sudden severe chest pain (even if not radiating to left arm);

sudden breathlessness (or cough with blood-stained sputum);

unexplained swelling or severe pain in calf of one leg;

severe stomach pain;

serious neurological effects including unusual severe, prolonged headache especially if first time or getting progressively worse or sudden partial or complete loss of vision or sudden disturbance of hearing or other perceptual disorders or dysphasia or bad fainting attack or collapse or first unexplained epileptic seizure or weakness, motor disturbances, very marked numbness suddenly affecting one side or one part of body;

hepatitis, jaundice, liver enlargement;

blood pressure above systolic 160 mmHg or diastolic

95 mmHg;

prolonged immobility after surgery or leg injury;

detection of a risk factor which contra-indicates treat- ment (see Cautions and Contra-indications under Com- bined Hormonal Contraceptives below or under Oestro- gens for HRT (section 6.4.1.1)).

COMBINED HORMONAL CONTRACEPTIVES

Indications contraception; menstrual symptoms (sec-

tion 6.4.1.2) Cautions see notes above; also risk factors for venous

thromboembolism (see below and also notes above), arterial disease and migraine, see below; personal or family history of hypertriglyceridaemia (increased risk of pancreatitis); hyperprolactinaemia (seek specialist advice); history of severe depression especially if induced by hormonal contraceptive; undiagnosed breast mass; gene mutations associated with breast cancer (e.g. BRCA 1); sickle-cell disease; inflamm- atory bowel disease including Crohn’s disease; reduced efficacy of contraceptive patch in women

and Appendix 1 (oestrogens, progestogens) Risk factors for venous thromboembolism See also notes above. Use with caution if any of following factors

present but avoid if two or more factors present: .

family history of venous thromboembolism in first-degree relative aged under 45 years (avoid contraceptive con- taining desogestrel or gestodene, or if known prothrom- botic coagulation abnormality e.g. factor V Leiden or antiphospholipid antibodies (including lupus anti- coagulant));

obesity —body mass index above 30 kg/m (avoid if body mass index above 39 kg/m );

long-term immobilisation e.g. in a wheelchair (avoid if confined to bed or leg in plaster cast);

history of superficial thrombophlebitis ;

age over 35 years (avoid if over 50 years);

smoking . Risk factors for arterial disease Use with caution if any one of following factors present but avoid if two or more factors present: .

family history of arterial disease in first degree relative aged under 45 years (avoid if atherogenic lipid profile);

diabetes mellitus (avoid if diabetes complications pre- sent);

hypertension —blood pressure above systolic 140 mmHg or diastolic 90 mmHg (avoid if blood pressure above systolic 160 mmHg or diastolic 95 mmHg);

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