We thank Dr Melvin for her comments.1 All our recommendations,2 including the examples she quotes, were made precisely because of the need she highlights for “pragmatic and common sense advice in this area of medicine where robust evidence is often lacking and the consequences of contraceptive failure are serious”. We submit that, in the real world where condoms are so often rejected or very poorly used, it is hardly pragmatic only to offer added condom use in the circumstances quoted; especially as there is strong biological plausibility to support the practice of increasing the dose of the relevant contraceptive hormone(s) and moreover the Clinical Effectiveness Unit (CEU) approves of this for the combined oral contraceptive pill,3 why not for the progestogen-only pill?

Condom advice is of course irrelevant to hormonal emergency contraception. With respect to increasing the dose of ulipristal acetate, the latest CEU statement3 is correct that there is “no evidence that this is effective”, presumably meaning as measured by conceptions prevented. However, it is equally true that there is no evidence that this is not effective. Moreover, does not the same absence of definitive clinical data apply to increasing the dose of levonorgestrel emergency contraception, which does have the CEU's approval3?

We did not recommend the long-term use of added desogestrel with the progestogen implant for women taking enzyme-inducing drugs, since this largely negates the pill-free use of the implant; but oral desogestrel might be useful short term while alternative contraception is considered, for women starting on enzyme-inducing drugs who already have an implant.

It is indeed a complicated subject. We look forward to the much-needed latest update of the Faculty guidance on Drug Interactions with Hormonal Contraception,4 due to be published in January 2011, and with all Faculty members, we were grateful to have had an opportunity to comment on the draft guidance document at http://www.fsrh.org prior to publication.