1-1banner
 
medpundit
 

 
Commentary on medical news by a practicing physician.
 

 
Google
  • Epocrates MedSearch Drug Lookup




  • MASTER BLOGS





    "When many cures are offered for a disease, it means the disease is not curable" -Anton Chekhov




    ''Once you tell people there's a cure for something, the more likely they are to pressure doctors to prescribe it.''
    -Robert Ehrlich, drug advertising executive.




    "Opinions are like sphincters, everyone has one." - Chris Rangel



    email: medpundit-at-ameritech.net

    or if that doesn't work try:

    medpundit-at-en.com



    Medpundit RSS


    Quirky Museums and Fun Stuff


    Who is medpundit?


    Tech Central Station Columns



    Book Reviews:
    Read the Review

    Read the Review

    Read the Review

    More Reviews

    Second Hand Book Reviews

    Review


    Medical Blogs

    rangelMD

    DB's Medical Rants

    Family Medicine Notes

    Grunt Doc

    richard[WINTERS]

    code:theWebSocket

    Psychscape

    Code Blog: Tales of a Nurse

    Feet First

    Tales of Hoffman

    The Eyes Have It

    medmusings

    SOAP Notes

    Obels

    Cut-to -Cure

    Black Triangle

    CodeBlueBlog

    Medlogs

    Kevin, M.D

    The Lingual Nerve

    Galen's Log

    EchoJournal

    Shrinkette

    Doctor Mental

    Blogborygmi

    JournalClub

    Finestkind Clinic and Fish Market

    The Examining Room of Dr. Charles

    Chronicles of a Medical Mad House

    .PARALLEL UNIVERSES.

    SoundPractice

    Medgadget
    Health Facts and Fears

    Health Policy Blogs

    The Health Care Blog

    HealthLawProf Blog

    Facts & Fears

    Personal Favorites

    The Glittering Eye

    Day by Day

    BioEdge

    The Business Word Inc.

    Point of Law

    In the Pipeline

    Cronaca

    Tim Blair

    Jane Galt

    The Truth Laid Bear

    Jim Miller

    No Watermelons Allowed

    Winds of Change

    Science Blog

    A Chequer-Board of Night and Days

    Arts & Letters Daily

    Tech Central Station

    Blogcritics

    Overlawyered.com

    Quackwatch

    Junkscience

    The Skeptic's Dictionary



    Recommended Reading

    The Doctor Stories by William Carlos Williams


    Pox Americana: The Great Smallpox Epidemic of 1775-82 by Elizabeth Fenn


    Intoxicated by My Illness by Anatole Broyard


    Raising the Dead by Richard Selzer


    Autobiography of a Face by Lucy Grealy


    The Man Who Mistook His Wife for a Hat by Oliver Sacks


    The Sea and Poison by Shusaku Endo


    A Midwife's Tale by Laurel Thatcher Ulrich




    MEDICAL LINKS

    familydoctor.org

    American Academy of Pediatrics

    General Health Info

    Travel Advice from the CDC

    NIH Medical Library Info

     



    button

    Wednesday, February 26, 2003

    Rat Poison for Life: I’m late to this one, but the latest medical breakthrough is the story of warfarin and its ability to safely prevent blood clots when taken for life:

    Until now, there has been no proven long-term therapy that is safe for high-risk patients. When a clot develops, people are usually given warfarin for three to six months, but then the drug is stopped, because it increases the risk of severe bleeding. Without warfarin, however, almost a third of the patients will form another clot within eight years.

    The new study has found that after a few months of standard treatment with full doses of warfarin, clots can be prevented with lower doses, about half of what is normally used to treat someone with a clot. The lower doses provide a safe middle ground, reducing the risk of more clots without increasing the risk of hemorrhage.


    That certainly sounds wonderful. Warfarin has been around for over fifty-years, so it’s available in a safe and effective generic version, although in 1998 only 18% of users chose the generic. It was first discovered in the 1930’s when researchers investigated the cause of hemorrhagic illnesses in free-ranging cattle. What they found was a substance called coumarin that’s present in the stems of sweet clover. Coumarin gave rise to warfarin which is the active ingredient in most rat and mouse poisons, and in more refined form, available for human therapy under the brand name Coumadin.

    Warfarin has its drawbacks. Not only does it increase the risk of bleeding by inhibiting blood clotting, but its metabolism is easily influenced by outside factors, so that the amount of clotting inhibition that occurs at any given dose can fluctuate depending on what other substances a person has ingested - both in terms of other drugs and in terms of food. It’s so easily influenced, in fact, that someone’s written a Coumadin cookbook to help patients prepare meals that won’t interfere with their Coumadin therapy.

    This means that the drug requires very close monitoring to be used safely. When everything is stable, that usually translates into once a month blood tests to insure that the anticoagulation effect is within the therapeutic range - neither too high, nor too low. But, if a dosage change is required, or if a new medication is introduced, then that testing becomes more frequent, usually within a week or a few days of starting the medication. That can mean a major life-style hassle for the patient, as well as an expense. Most of my warfarin patients complain bitterly about being on it.

    And that’s what bothers me about this study. It only tracks the risk of taking warfarin over a mean of two years
    The trial was terminated early after 508 patients had undergone randomization and had been followed for up to 4.3 years (mean, 2.1).

    We don’t know how that risk pans out after ten, fifteen, or thirty years of warfarin therapy. That’s something that we should keep in mind before rushing to put everyone on it for life. But that doesn’t stem author Dr. Paul Ridker’s (
    of C-Reactive Protein fame) enthusiasm:

    "This really ought to change the standard of care overnight," said Dr. Paul Ridker, the first author of the study and director of the center for cardiovascular disease prevention at Brigham and Women's Hospital in Boston.

    But, as the accompanying editorial points out, not only is warfarin tricky to use, there is some conflicting data out there that isn’t getting quite the publicity that this piece is (In fact, I couldn’t locate a link to the article the editorial mentions):

    However,Kearon et al.have simultaneously reported in preliminary form the results of a different randomized,double-blind trial of similar size that found that low-intensity warfarin (INR,1.5 to 1.9 )was significantly less effective than conventional-intensity warfarin (INR,2.0 to 3.0)for extended prevention of recurrent venous thromboembolism, without significant differences in the rate of bleeding complications. It is difficult to reconcile these findings and to make definitive recommendations regarding the optimal intensity of anticoagulation therapy for long-term secondary prevention without data from a risk –benefit analysis in a three-way comparison of conventional-intensity,low-intensity,and no anticoagulation therapy following at least three months of conventional-intensity warfarin therapy for an initial episode of venous thromboembolism.

    In other words, curb your enthusiasm.
     

    posted by Sydney on 2/26/2003 08:44:00 AM 0 comments

    0 Comments:

    Post a Comment

    This page is powered by Blogger, the easy way to update your web site.

    Main Page

    Ads

    Home   |   Archives

    Copyright 2006