Prescriber Update Articles

Ministry of Health (Medsafe) advice on the use of combined oral contraceptives

March 2002 update

Prescribers are advised to consider the following recommendations when prescribing combined oral contraceptives (OCs).

The view of the Medicines Adverse Reactions Committee (MARC) and the Ministry of Health is that:

• the risk of venous thromboembolism (VTE) with the third generation OCs is approximately twice that with the second generation OCs;
• third generation OCs do not appear to possess significant additional health benefits (e.g. reliability of contraception, reduction in the risk of cardiovascular disease) above the second generation OCs, other than improvement in tolerability and quality of life in some patients;
• third generation OCs may be prescribed for women who have adverse effects such as breakthrough bleeding or androgenic side effects with second generation OCs;
• the risk of VTE with OCs containing cyproterone (a progestogen with anti-androgenic properties) is at least as great as that with the third generation OCs.

When initiating contraceptive therapy the prescriber should:

• take a comprehensive personal and family history to exclude contraindications to the use of combined OCs. If there is a family history of thromboembolism, screening for thrombophilia should be considered in consultation with a haematologist. Hereditary thrombophilia and personal history of VTE are contraindications;
• counsel women about the risks and benefits associated with the use of all forms of contraception;
• consider prescribing a combined OC, containing no more than 35mcg ethinyloestradiol and a progestogen other than desogestrel, gestodene or cyproterone, where the woman has no contraindications to the use of a combined OC and has indicated that she wishes to take a combined OC. Prescribe an OC containing a higher dose of oestrogen only if it is specifically indicated.
• advise women about the symptoms of VTE, especially pulmonary embolism, and situations of increased risk.

When reviewing combined OC therapy the prescriber should:

• review the personal and family history to identify contraindications for the use of combined OCs and risk factors for VTE as for initiation of therapy;
• counsel about the risks and benefits associated with the use of the contraceptive the woman is currently taking compared to the risks and benefits of other forms of contraception;
• if contraindications to the use of combined OCs are present, another form of contraception should be agreed upon;
• women prescribed a combined OC should be advised about symptoms of VTE, especially pulmonary embolism, and situations of increased risk.

For women taking OCs containing desogestrel, gestodene or cyproterone:

• in the presence of thromboembolic risk factors, the woman should be advised to change to an OC that does not contain desogestrel, gestodene or cyproterone, or change to another contraceptive method, as appropriate. For women taking an OC containing cyproterone an alternative treatment for the androgenic disease may be required;
• offer other hormonal or non-hormonal contraception if, after counselling, the woman finds the relative risk of VTE with combined OCs containing desogestrel, gestodene or cyproterone unacceptable;
• respect the woman's informed choice if she chooses to continue to take her current contraceptive.

Risk factors for VTE

* Contraindications for combined OCs
^# Usually temporary risk factors