When Plan B really isn’t

Russell Saunders

Russell Saunders is the ridiculously flimsy pseudonym of a pediatrician in New England. He has a husband, three sons, daughter, cat and dog, though not in that order. He enjoys reading, running and cooking. He can be contacted at blindeddoc using his Gmail account. Twitter types can follow him @russellsaunder1.

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26 Responses

  1. Alan Scott says:

    So does the medical profession know, basically, what’s up with those results?

    Is it just a question of not taking enough for body mass? If a woman who weighed 200+ pounds took an extra half a pill, would it be effective? Or is it more complicated than that?Report

    • Honestly, I don’t know how to answer that question. The mechanism by which EC prevents pregnancy has been a subject of some debate in itself, and how to better accomplish it for women with higher BMI is a question for scientists with greater expertise in the area of reproductive endocrinology than I.Report

  2. Mike Schilling says:

    It must have taken a lot of research to pinpoint that ineffectiveness starts at precisely165 pounds and becomes total at exactly 176.Report

    • scott the mediocre in reply to Mike Schilling says:

      Five kilo steps seems like a reasonable size for experimental design, but yah, weight isn’t BMI and in individual cases the correlation between gross BMI and the biochemical markers of obesity-induced morbidity isn’t that strong (as opposed to large population aggregates, where the p value on BMI to markers _is_ pretty good). I suspect 🙂 it’s probably unrealistic for labelling to say something like “may not be effective if the following function of your HDL/LDL level, triglycerides, resting HR, … is greater than X”).Report

      • Kim in reply to scott the mediocre says:

        Measuring central adiposity isn’t that hard.
        Some might argue it’s easier than BMI,
        as not everyone has a scale at their disposal.Report

      • Fnord in reply to scott the mediocre says:

        In fact, the study itself does measure BMI rather than weight. Which the study authors admit is a weakness, or at least an area needing further study, since they can’t say exactly what the cause of failure is, so they don’t know how it effects (inter alia) women who are heavy because they’re tall.Report

    • Since those recommendations are based on internal data analyses, I have no idea how they arrived at those numbers.Report

  3. NewDealer says:


    How do you feel about the American Board of Obstricians threatening loss of certification for OB-GYNs who treat men for Anal Cancer?


    • Short answer: ARGH! ARGH! ARGH! ARGH! ARGH!!!!!

      Medium answer: This would be a prime example of a non-governmental entity enforcing the powers of its cartel such that licensure should be a relatively small-potatoes concern for libertarians.

      Long answer: That post I’ve been mulling about board certification for lo these many months.Report

    • veronica dire in reply to NewDealer says:


      So I wonder who I’ll go see for a mammogram? Like, if these bright-bulbs decide I’m “male.”Report

  4. Fnord says:

    Ungated version of the study is available here. Note that it’s not placebo controlled, merely a comparison between different drugs and different conditions. It clearly demonstrates that Plan B (levonorgestrel) is significantly less effective in overweight and (especially) obese women than it is in women with lower weight, and that it’s less effective than the newer ulipristal acetate in those women. Which is good to know, along with the data point that ulipristal acetate may not be more effective than levonorgestrel in other women.

    Because it’s not placebo-controlled, it doesn’t demonstrate by itself that levonorgestrel is completely ineffective even in obese women. There’s a citation to another study that apparently reveals the pregnancy rate among women who don’t use emergency contraception at all, but I haven’t been able to find an ungated full version of that study, and I don’t know if it’s actually valid to compare pregnancy rates in different study populations like that, particularly since it’s comparing just a subset of one study population (obese women) to another study population where weight is not measured (according to the JSTOR preview).Report

  5. DBrown says:

    And how often have you warned your pateints about the extreme dangers of Tylenol? How many hundreds (or even thousands by some estimates) of people out there SUFFER TOTAL LIVER FAILURE BECAUSE THIS OVER THE COUNTER DEADLY MED ISN’T CONTROLED? The standard dose is very close to a deadly dose (just taking two or three other meds that also contain tylenol can do it. That is far too easy for a over-the-counter med.) Worse, just a drink or two with a standard dose can also kill someone’s liver. This drug is far too dangerous to be over-the-counter and doctors need to warn people of the dangers due to it being in so many other meds.Report

  6. Jaybird says:

    In light of this new information, is it a bad idea to argue that Obamacare shouldn’t cover Plan B for women who weigh more than 176 pounds?Report