Effect Measure

Tamiflu, pregnancy and public health

Here’s a particularly worthless article from the AP: Docs say Tamiflu won’t affect foetus.

This is clearly an important question. In the event of a pandemic, Tamflu will be used prophylactically in pregnant women, either by choice or because the women don’t know they are pregnant. There is currently no reliable information on effects of this drug on a developing fetus, and there may not be before we are faced with the problem. So data points are useful. But this example is utter non-sense.

In Jakarta, Indonesian doctors are giving a 35 year old 2 months pregnant woman Tamiflu after she developed bird flu symptoms. They will be monitoring her closely for effects on her pregnancy. Entirely reasonable and a useful exercise. But not much information to be gained. If there is a problem, this is an older mother in a country where pregnancy and childbirth still has many complications and who may be ill with a serious disease with its own effects on reproduction. If there is no problem, we have just a single data point. Suppose the risks were extraordinarily high, i.e., 50% of pregnant women suffered immediate miscarriages. The lack of miscarriage in this case wouldn’t be particularly informative, perhaps only assuring us the risk was not higher than, say 95%.

Which is why we think both the headline and this statement by the Indonesian doctor are ridiculous:

Dr Luhur Soeroso, who is treating the 35-year-old woman from Sumatra province, said she has been taking the drug for over one week and “so far has not had any problems with her pregnancy.”

He said he believed other strong antibiotics being administered to the patient, who continues to suffer from high fever and respiratory problems, were more dangerous to the foetus’ development than Tamiflu. (AP)

Dr. Luhur only knows the drug didn’t cause an immediate miscarriage. Any other effects on the fetus are unknown. Nor does he know what the risk of an immediate miscarriage is, only that it isn’t 100% and probably not 90 – 95%. Nor, I suspect, does he have any idea of the risks of the antibiotics he is using. To sum up, pretty much Dr. Luhur has no idea.

The question is important. Until it is answered, we will be doing the usual blind risk – risk trade-offs. A robust and effective public health infrastructure able to monitor, surveil and follow-up public health interventions like prophylactic Tamiflu use could answer this question at some point, although probably only after some event triggered widespread use of the drug. So the information would not be available if a pandemic were to occur in the near future, even if we had such infrastructure (which we don’t).

But it is very discouraging to think that whatever information might be gleaned about this important topic will be lost in any event, because we didn’t invest in an effective public health and social service system (including maternal and child health public health services).

Comments

  1. #1 Kevin
    August 29, 2006

    Isn’t Tamiflu proscribed routinely for seasonal influenza in Japan? Not to pregnant women?

  2. #2 LibraryLady
    August 29, 2006

    Revere:
    Can you please check some information for us? On 8-14-06 the Fish and Wildlife Service–APHIS–conducted a press conference to explain the finding of low-path H5N1 in 2 mute swans in Michigan. Google “aphis avian influenza” to find the transcript. They said the virus had been identified for type and would be further tested for virulence by growing the virus and injecting the product into baby chicks. This would take about 2 weeks to complete. It is now 2 weeks past. Have you heard anything about the results of this testing? I cannot find anything.

    A related question: If the baby chicks died from this virus, what does it mean for public health planners?

    Thank you,
    Library Lady

  3. #3 revere
    August 29, 2006

    LL: The Reveres are frolicking together and none of us are at our homebase. Our joint vacation ends this weekend (sigh). In answer to your question, however, we understand the tests were negative (i.e., that it was low path). Here is a news article: http://www.newsmax.com/archives/articles/2006/8/28/201823.shtml?s=he

  4. #4 Science Teacher 2
    August 29, 2006

    Dear Reveres, Can you please comment on the ongoing situation in Indonesia? Pretty Please?
    http://www.fluwikie2.com/pmwiki.php?n=Forum.IndonesiaOubreakCaseSummariesNOCOMMENTARYPLEASE

  5. #5 tan06
    August 30, 2006

    Last year I have written GSK in september 2005 about the effects of Tamiflu on children unborn and under age 1.
    I got the following answer (translated from Dutch):

    “About Tamiflu in pregnancy insufficient data are excisting. Although animal experiments do not point to harmful effects, we have to be on the safe side because of lack of data on humans.
    The use of Tamiflu for children younger than 1 year old has to be resolutely advised against.
    The fact is that it appeared from experiments on young rats Tamiflu can pass the not full-grown blood-brain barrier and this was associated with mortality among those little rats. In humans the blood-brain barrier is full-grown from the age of 1 year and this is why Tamiflu can be prescribed only from that age on.”

    You give some very right arguments, Revere.
    Viruses are harmful to the unborn child. Especially in the first trimester of pregnancy. Not to say the Tamiflu factor complicates the outcome. This is something like a ad-hoc N=1 experiment and it’s too early to talk about final results. It kan take at least 9 months when these people survive H5N1. As far as I know no pregnant woman survived H5N1 and had a healthy child from delivery afterwards.

    There is an interesting news publication on immunization against H5N1 by blood transmission from surviving patients:

    http://www.eurekalert.org/pub_releases/2006-08/acop-aos082806.php

  6. #6 tan06
    August 30, 2006

    Btw Thank you, Mary from Hawaii and others for answering the question about the necessary size of clusters to move from pandemic stage 3 to 4 or 5!

  7. #7 Marissa
    August 30, 2006

    Tan06: I believe the MR for pregnant women in the 1918 pandemic flu was about 70-75%, so treatment is always going to be a weighing of the risks.

    Science Teacher 2: I agree with Revere’s last posting on the subject. Big picture: a continual dribble of cases, some small clusters of which some have limited h-2-h transmission. Unknown reservoir infecting some of these cases. A high proportion of cases not reported because they are admixed with the seasonal flu population–MR too high for the group to assume seasonal flu mortality

  8. #8 Theresa42
    August 30, 2006

    The woman from Sumatra has, unfortunately, miscarried. She has also reportedly tested negative for bird flu:

    http://www.flutrackers.com/forum/showpost.php?p=28275&postcount=28

  9. #9 mary in hawaii
    September 1, 2006

    The doctor reports, after one week of tamiflu, that the woman “so far has not had any problems with her pregnancy.” Then today when she dies, he claims that she was bleeding from the uterus from the time she first came in for treatment, and that the foetus all along was “very weak”. Ok, doc, so which was it…no problems with the pregnancy or an incipient miscarriage from day one. Or do we just change the story as it suits our needs?

    here’s a link to the article re the miscarriage:

    http://www.iht.com/articles/ap/2006/09/01/asia/AS_GEN_Indonesia_Bird_Flu_Pregnancy.php

  10. #10 Michele
    June 18, 2009

    My daughter was unknowingly 4 weeks pregnant when prescribed Tamiflu for SwineFlu like symptoms. She suffered a miscarriage in the 8th week.

  11. #11 revere
    June 18, 2009

    Michele: I know from personal experience how wrenching and painful these things are, as my daughter lost a baby at 26 weeks. For what it’s worth, the evidence doesn’t implicate Tamiflu in miscarriage. Small comfort I know.

  12. #12 Renee
    July 20, 2009

    I was diagnosed with Swine Flu the same day I was notified I was 2 weeks pregnant. I was prescribed Tamiflu, and after 2 pills I suffered a miscarriage.

  13. #13 Renee
    July 20, 2009

    I was diagnosed with Swine Flu the same day I was notified I was 2 weeks pregnant. I was prescribed Tamiflu, and after 2 pills I suffered a miscarriage.

  14. #14 nil
    September 4, 2009

    I think that everyone should take a decision himself, take him to Tamiflu or not. My sister took Tamiflu and all went well – she is healthy. If you have any doubts, it is best to consult a doctor. Get better! Incidentally, my sister bought the medicine on the Internet, if someone need something that’s Address (not ads)www.ekpharm.org

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