Advising women on which pill to takeBMJ 1995; 311 doi: https://doi.org/10.1136/bmj.311.7013.1111 (Published 28 October 1995) Cite this as: BMJ 1995;311:1111
- John Guillebaud
- Professor of family planning and reproductive health Margaret Pyke Family Planning Centre London W1P 1LR
The informed user should be the chooser
Rarely can an editorial in the BMJ have been so difficult to write. The warning about oral contraceptives containing desogestrel and gestodene that was sent to all British doctors and pharmacists on 18 October by the Committee on Safety of Medicines1 was based on three as yet unpublished epidemiological studies. Scientific etiquette forbids those of us who have seen drafts of the papers from commenting in detail, if only because the peer review process is not complete and the articles may be considerably altered before publication. For most doctors, who do not have access to the relevant data, advising patients is particularly difficult.
Despite important questions about the biological plausibility and validity of the findings (see p 1112), three studies in different populations with two different methodologies show results that are congruent and generally statistically significant. If we do not like the message we should not shoot the messenger (though legitimate questions may be asked about the timing of the announcement, procedures for circulating information to doctors, and the detailed content of the committee's letter). And, given that the letter now exists and will (however sound its basis proves to be) inevitably change the context of prescribing practice worldwide, what are the detailed implications for prescribers?
Firstly, women should be reassured that these new studies confirm the amazing safety of all modern formulations of the combined pill with regard to idiopathic venous thromboembolism. Even the products containing desogestrel and gestodene are estimated to lead to only 30 cases in 100000 compared with 60 cases in 100000 pregnancies. Women can be told that for the first time the effects of different brands of pill can be assessed. They can also be told that it is possible that some low oestrogen varieties containing the older, “second generation” progestogens levonorgestrel and norethisterone with its prodrugs, are even safer than was previously thought, with rates of about 15 cases of venous thromboembolism per 100000 users compared with about 5 cases per 100000 non-users.2 Fortunately, the mortality from venous thromboembolism is low (estimated to be 1-2%), so that mortality is estimated to be no higher than 2-3 per million users. This compares favourably with all cause mortality in pregnancy and with the risks that many people accept in daily life. Women may also be reminded of the contraceptive and established non-contraceptive benefits of the pill method, including protection against carcinoma of the ovary and endometrium, pelvic inflammatory disease, and disorders of the menstrual cycle.3
I agree with the Committee on Safety of Medicines that pills containing desogestrel and gestodene are contraindicated if a woman's body mass index is above 30 or if she has varicose veins, which are a marker of risk of deep venous thrombosis; and I would add to these contraindications immobility and a family history of venous thrombosis. (A personal history of thrombosis has always and rightly been an absolute contraindication to any pill containing ethinyloestradiol.) I would also now recommend the use of pills containing levonorgestrel or norethisterone for women under the age of 30 who are free of risk factors for arterial disease.
Continued role for third generation pills
So how should doctors advise women above the age of 30 without risk factors for arterial disease? And how should they advise women of any age who are heavy smokers or who have moderate hypertension, uncomplicated diabetes, or a family history of arterial disease with normal lipid concentrations (complicated diabetes and abnormal lipid concentrations being absolute contraindications)? Here I will give my personal view, which is that such women should be fully informed of the possibility that, by continuing or starting a low oestrogen plus desogestrel or gestodene pill, they may be increasing their risk of venous thromboembolism by up to 15 per 100000; but that on the basis of other data, they may be less likely to suffer a (more dangerous) heart attack or stroke than they would be if they were taking a brand containing levonorgestrel or norethisterone.
Knowing everything that I know, if I were a woman I would prefer such a product for myself. So I am comfortable in informing BMJ readers that, pending further analysis and full publication of the data, the policy at the Margaret Pyke Family Planning Centre will be to continue to offer these products to fully informed women with risk factors for arterial disease. And not only to them. Other women may also choose to continue or start products containing desogestrel or gestodene after a carefulanalysis of their personal risks and benefits in comparison with their actual or predictable “intolerance” (to use the committee's word) of alternative pills or other contraceptive methods. This counselling will include consideration of so called “minor” but important side effects such as breakthrough bleeding, acne, headaches, and weight gain--conditions that our experience has shown often benefit from desogestrel or gestodene in combination with low doses of ethinyloestradiol. We believe that “the user should be the chooser” when it comes to contraception, provided that she is fully informed. The committee's letter has added further complexity to the information that needs to be communicated.
Finally, in future how might distress among both prescribers and consumers be minimised when new research data affecting prescribing need to be conveyed? Difficult though it will always be, some system ought to be devised to ensure that the vast majority of doctors and pharmacists have received such information at least 24 hours ahead of the media. This can be achieved only with a rigidly enforceable embargo for the media. More importantly, such decisions should, except in extreme circumstances, be announced at the time of full publication of the data rather than weeks in advance. And might not future letters from the Committee on Safety of Medicines incorporate input from actual prescribers of the treatment involved, including a user friendly A4 sheet that doctors could photocopy and give out to patients in their waiting rooms? Readers will doubtless wish to add to these suggestions.