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Drug that causes B12 Deficiency

Discussion in 'Step I' started by DMBFan, Jun 19, 2008.

  1. DMBFan

    DMBFan Senior Member 7+ Year Member

    Mar 18, 2004
    I know that B12 is very hard to be deficient in, but I don't know if I am going crazy, but I swear there was some drug that caused B12 deficiency. I Wikipedia'ed it - and found that chloroamphenical reduces it, but I'm not sure if that's the one that I saw somewhere and Goljan mentioned....Can anyone help me out? I may be wrong about a drug causing this reaction,t hough.
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  3. lilnoelle

    lilnoelle Moderator Emeritus 7+ Year Member

    Feb 21, 2006
    Maybe your talking about B6 and Isoniazid?
  4. hmgcoa

    hmgcoa Member 7+ Year Member

    Jul 13, 2002
    dallas, tx
    all that comes to mind is phenytoin and folic acid (correct me if i'm wrong. just took the test a few days ago and my mind is mush right now...)

    something about how it blocks intestinal conjugase thereby preventing the conversion of poly to mono folic acid?
  5. osli

    osli Senior Member 5+ Year Member

    Oct 13, 2005
    valproic acid does something similar.

    Halothane causes megaloblastic anemia... not sure of the mechanism...?

    Nothing comes to mind for B12.

    LUBDUBB Freakaholic 10+ Year Member

    Oct 7, 2002
    Megaloblastic Anemia can be due to a bunch of drugs.

    Folate def due to intestinal conjugase block by EtOH and OCP (according to RR Goljan)
  7. f1re11

    f1re11 7+ Year Member

    May 23, 2008
    Id guess a proton pump inhibitor like Omeprazole
  8. Nicholaus

    Nicholaus Fellow 7+ Year Member

    Dec 9, 2007
    Quite difficult to get B12 def considering you have many years supply stored in the liver. However, folate def is much more common and can be caused by a whole host of drugs (i.e. DHFR inhibitors, etc.).
  9. crazy_cavalier

    crazy_cavalier T3-Weighted 7+ Year Member

    Are you sure it's a drug you're thinking of?? Because D. lattum (fish tapeworm) can cause B12 deficiency. Maybe that's the one you're thinking of.
  10. phospho

    phospho SDN Lifetime Donor Lifetime Donor Classifieds Approved 10+ Year Member

    Jun 4, 2006
    Columbus, OH
    i'm just a premed, but the diabetes medication, metformin, may interfere with B12 dietary absorption (from wiki)
  11. GynGuy1983

    GynGuy1983 C&A Psychiatry Fellow 7+ Year Member

    Jun 13, 2008
    Rathke's pouch

    I've never heard of any meds causing B12 deficiency. If there is, I would expect that it would be very low yield to begin with.
  12. blake44


    Jun 20, 2008
    you might be thinking of phenytoin. (it interferes with vitb12 metabolism --> megaloblastic anemia).

    wow... that made me come out of lurking. i was just studying, and i saw that, and i thought immediately of this post. now i hope it's on my exam
  13. DMBFan

    DMBFan Senior Member 7+ Year Member

    Mar 18, 2004
    I was thinking of Isonazid and B6...Thanks. So many things in my head, I can't even remember even basic things :)
  14. GynGuy1983

    GynGuy1983 C&A Psychiatry Fellow 7+ Year Member

    Jun 13, 2008
    Rathke's pouch
    It happens to the best of us. Just keep in mind that you need to supplement the TB patient with B6 otherwise they're more likely to suffer from neuropathy (more so than hepatotoxicity).

    Keep your head up!
  15. doctorFred

    doctorFred intensive carer Physician Faculty 10+ Year Member

    May 5, 2005
    , location, location!
    therapeutic injection of diphylobothrium eggs directly into your eyeballs. it also causes blindness for some reason.
  16. GynGuy1983

    GynGuy1983 C&A Psychiatry Fellow 7+ Year Member

    Jun 13, 2008
    Rathke's pouch
    In UW, wasn't there an alcoholic patient that only became deficient in B12 after 2 years or so?

    I'd prefer a direct injection of Loa Loa to my eye, at least then I might make it on one of those stupid medical shows.
  17. ijcMD

    ijcMD Senior Member 7+ Year Member

    May 28, 2006
    New York
    yes, i saw that question yesterday... it was a homeless patient though
  18. Aseptic Pimp

    Aseptic Pimp Junior Member 5+ Year Member

    Dec 27, 2005
    You are definitely talking about Phenytoin. In the FA 2006 version it says Phenytoin causes Vit B12 def, however Goljan states that Phenytoin actually cuases a deficiency in folic acid.

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