The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

Letter to the editor

Editor, – I was fortunate to read the excellent article about missed doses (Aust Prescr 2002;25:16-8) but I did find myself questioning the advice given in the table 'Information for consumers' for progestogen only contraceptives. This indicated that if a dose of the progestogen only pill is delayed for more than three hours then back-up contraception is required for 14 days. This would seem contrary to the evidence that the cervical mucus protection afforded by this method begins after only about three hours and that the suppressive effect on the endometrium only takes a few days to occur. It is accepted practice in most family planning organisations worldwide that women are advised that should they be more than three hours late taking a dose of their progestogen only pill they should use additional contraceptive cover for two days, not 14 as stated in the article. I agree that many of the recommendations around the use of progestogen only contraceptives are 'fuzzy' to say the least!

Perhaps at some stage in the future someone will have the energy to apply to the appropriate authorities to lift the restrictions on the use of progestogen-only contraceptives in women who are lactating or have thrombophilia. It is hard enough for the poor doctor just trying to do the right thing without having product information that is palpably inaccurate as well.

Terri Foran
Medical Director FPA Health
Ashfield, NSW

Author's comments

Dr Andrew Gilbert, one of the authors of 'I've missed a dose; what should I do?', comments:

We thank Dr Foran for her comments. Our article presented information as it is printed in the Consumer Medicine Information (CMI) sheet for levonorgestrel (Microval). The information in the CMI is required to be consistent with the Australian approved product information. It is clear from Dr Foran's comments that the product information, and therefore the CMI, does not reflect current clinical knowledge about the use of progestogen-only pills. With regard to missed doses, the product information for Microval states that in cases where a woman misses either one or two tablets 'she should use a mechanical method of contraception until 14 consecutive tablets have been taken'. The product information for the Micronor brand of norethisterone states even more strongly that if one dose is missed the pill 'should be discontinued immediately and a method of non-hormonal contraception should be used until menses have appeared or pregnancy has been excluded'.

We believe that it is extremely important that the product information and CMI reflect the evidence we have about the safe, effective and convenient use of these products in practice. We support strongly Dr Foran's contention that a mechanism needs to be found to require the pharmaceutical companies to update their product information in light of good practice-based evidence.