Choosing a Combined Oral Contraceptive (COC)

All UK licensed COCs now contain less than 50 micrograms of oestrogen. Generally a preparation with the lowest oestrogen and progestogen content that gives good cycle control and minimal side effects in the individual woman should be chosen.

Progestogen may be ranked in order of decreasing adrogenicity as follows: Norethisterone (NET) - levonorgestrel (LNG) - norgestimate - gestodene (GSD) - desogestrel (DSG) - drospirenone - cyproterone.

First and second line COC choices are shown below. A later section gives advice on preparations that may be tried to overcome specific problems.

All currently available low doses COCs carry an extremely low risk for healthy women.

The risk of venous thromboembolism (VTE) in women is estimated to be (from Drug Safety Update April 2008):

Non-pregnant woman not taking an oral contraceptive = 5 - 10 cases per 100,000.

Use of the low dose pills containing the progestogen levonorgestrel or norethisterone = 15 cases per 100,000.

Use of the low dose pills containing the progestogen desogestrel or gestodene = 25 cases per 100,000.

Pregnant = 60 cases per 100,000.

Women taking liver enzyme-inducing drugs (eg some anti-epileptics) who wish to use COC should choose a regimen containing at least 50 micrograms EE daily. Additional contraceptive protection, such as condoms, should be used until 4 weeks after the liver enzyme-inducing drug has been stopped. Information should be given on the use of alternative methods of contraception if liver enzyme-inducing drugs are to be used long term. More information on interactions with anti-epileptics can be found in NICE Guidance CG137.

Combined oral contraceptives (COCs)

In order to establish the safety of combined oral contraception it is necessary to have an overview of the health status of the individual woman before first prescription of a COC:-

Clinical history - contra-indications (see link below) and conditions for which non-contraceptive benefits of COCs may be helpful eg menorrhagia

Clinical examination -

• Measure and record blood pressure
• Calculate Body Mass Index (BMI) where obesity is a concern
• Blood tests are unnecessary unless there is a clinical indication
• Breast and pelvic examinations are unnecessary in asymptomatic women, but follow local policy on cervical cytology.

Assessing risk factors before prescribing contraceptives

The UK Medical Eligibility Criteria (UKMEC) are a set of evidence-based recommendations designed to help women select the most appropriate method of contraception for specific clinical conditions without imposing necessary restrictions. Each clinical condition has a recommendation for contraceptive use, categorized according to the balance of benefits and harms weighted by their probabilities for the typical user with the condition. The categories are defined in Table 1, and the eligibility criteria in Table 2 (adapted from the Clinical Knowledge Summaries Topic on Contraception, (accessed 2/12/2009), which is based on the UK medical eligibility criteria for contraceptive use and other guidance published by the Faculty of Sexual and Reproductive Healthcare .

To use these UKMEC tables, the following information is required from the record, clinical history, and/or physical examination:

• Pregnancy: Current pregnancy status; time since delivery
• Breastfeeding status: only breastfeeding; primarily breastfeeding; partially breastfeeding; not breastfeeding
• Medical conditions (past and present), and specifically including:
• Headache; migraine with/without aura
• Cardiovascular disease: coronary heart disease; cerebrovascular disease; peripheral vascular disease
• Diabetes: duration; target organ damage (eyes, kidneys, nervous system)
• Cardiovascular risk factors (other than above): age; smoking habit; body mass index (obesity); blood pressure (hypertension); hyperlipidaemia
• Risk factors for venous thromboembolism: previous venous thromboembolism; thrombogenic mutations; family history of venous thromboembolism; Raynaud's disease (primary; secondary, with/without lupus anticoagulant); surgery (major; minor; with/without prolonged immobilization; immobility unrelated to surgery)
• Breast disease: undiagnosed mass; non-malignant conditions; breast cancer current/past; family history of cancer; carrier of gene mutation associated with breast cancer
• Liver or gallbladder disease including: jaundice; hepatitis (active/carrier); tumour
• Cancer: cervical cancer; gestational trophoblastic neoplasia; liver cancer
• Drugs use (prescription; non-prescription; herbal remedies): in particular anti-epileptics; antibiotics

Key to tables:

NET-EN = Norethisterone-oenanthate (not on formulary)

Cu-IUD = Copper Intrauterine Device

LNG-IUD = Levonorgestrel IUD (Minerva)

Imp = Implant

CHC = Combined Hormonal Contraception

POP = Progesterone Only Pill

DMPA - Depot Medroxyprogesterone Acetate

Readers are referred to the BNF for information on

• Missed pill
• Diarrhoea and vomiting
• Drug interactions
• Surgery
• Reason to stop immediately
• Dosing instructions

Link to: http://bnf.org/bnf/index.htm

Link to: http://www.fsrh.org/pages/clinical_guidance.asp