Keith’s GoutPal Story 2020 Forums Please Help My Gout! Whats shelf life of Allopurinol ?

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  • #3638
    limpy
    Participant

    Hi guys it's been a while since i've been on here. I'm in between doctors right now and i've ran out of my currant script of Allo.??I found a bottle thats a couple of years old. It says discards after 09. Now i'm wondering if this will still be good. The last thing?I need is an attack what do you guys think. Is it worth the risk?

    Allopurinol Tablets 100 mg photo

    #11973
    limpy
    Participant

    I?have more on the way but its mail order. So?I won't get it for a few days. I've been taking Allo every day for 18 months till my insurance ran out. And?I still haven't ran out?I was asking a simple question. Rather the old stuff would still be good to take till my order gets here??
    I've seen where Zip has said he taken Colchicine that was over 10 years old. Thanks for the help 🙂

    #11980
    limpy
    Participant

    All?I really wanted was to know if these would still do the job?

    #11981
    odo
    Participant

    Suck 'em and see. Pretty sure they won't do any harm.

    #11993
    Tavery
    Participant

    The US Government has made a broad law that (unless specifically designed) no pill medication can have a shelf life longer than 36…..well, to be honest, they mandated that any medication that will be advertised as having a longer shelflife will need to provide a whole slate of additional documentation to the FDA in support of that claim. So the drug companies said screw it and now all medications have a expiriation of 36 months or less.

    Your Pharmacy does not know exactly when each bottle of medication was manufactured or how long it sat in a warehouse before being shipped to them so they made a general rule that all medications expire about a year after the order is filled. Liquid meds have an even shorter life.

    Thousands of tons of medications expire every year and are still completely effective. They are usually shipped to areas such as Africa where people could care less about some arbitrary date set by a government.

    Assuming the botttle has not be subjected to moisture, high heat or direct sunlight for long periods of time, most pill medications last five years or more without a problem. If the pill is still firm and looks ok and smells ok, it is still probably good.

    Worst case is that it begins to lose effectiveness as it ages. The half-life of most kinds of antibiotics is approximately 7 years. Meaning at 7 years you would need a double dose. I dont know the numbers for Allopurinol.

    So, to answer your question. Yes, go ahead and take the older pills if they feel, look and smell ok. Take your normal dose. If it is slightly less effective…its better than taking nothing. Do not try to raise your dosage to compensate though because you dont know how much effectiveness it has lost and the danger of taking too much is worse than taking less than normal.

    #11928
    limpy
    Participant

    Tavery said:

    The US Government has made a broad law that (unless specifically designed) no pill medication can have a shelf life longer than 36…..well, to be honest, they mandated that any medication that will be advertised as having a longer shelflife will need to provide a whole slate of additional documentation to the FDA in support of that claim. So the drug companies said screw it and now all medications have a expiriation of 36 months or less.

    Your Pharmacy does not know exactly when each bottle of medication was manufactured or how long it sat in a warehouse before being shipped to them so they made a general rule that all medications expire about a year after the order is filled. Liquid meds have an even shorter life.

    Thousands of tons of medications expire every year and are still completely effective. They are usually shipped to areas such as Africa where people could care less about some arbitrary date set by a government.

    Assuming the botttle has not be subjected to moisture, high heat or direct sunlight for long periods of time, most pill medications last five years or more without a problem. If the pill is still firm and looks ok and smells ok, it is still probably good.

    Worst case is that it begins to lose effectiveness as it ages. The half-life of most kinds of antibiotics is approximately 7 years. Meaning at 7 years you would need a double dose. I dont know the numbers for Allopurinol.

    So, to answer your question. Yes, go ahead and take the older pills if they feel, look and smell ok. Take your normal dose. If it is slightly less effective…its better than taking nothing. Do not try to raise your dosage to compensate though because you dont know how much effectiveness it has lost and the danger of taking too much is worse than taking less than normal.

    Thanks for the info. Thats what?I was looking for.


    #23852
    Keith Taylor
    Participant

    Shelf Life of Allopurinol

    I got a related question recently on my gout help desk. When someone asked about the allopurinol expiration date. So that caused me to revisit this topic.

    I’m preparing a full review. But for now, some facts are:

    • Half-life is actually “elimination half-life”. That is, the time it takes for drugs to be excreted from the body to half the maximum concentration. It’s really a separate issue. So it’s best to start a new topic. Or ask in the help desk. But the main issue is that allopurinol quickly changes to oxypurinol. That is the important uric acid inhibitor. Studies indicate that the half-life of oxypurinol is 23 hours on average[1]. With a range wider than 17 to 39 hours. So missing a day is not as serious with allopurinol as with some drugs. Note that you must confirm this with your doctor. Because your situation might be different – especially with kidney problems.
    • I can only find 1 study related to the shelf life of allopurinol[2]. But it relates to allopurinol tablets crushed into a liquid. So not a definitive answer. But it found “The shelf-life (t90) of the suspension was found to be 8.3 years at room temperature”. Note that shelf life is measured as the time it takes for allopurinol to degrade to 90% of its original concentration.

    I’d like my review of the shelf life of allopurinol to be as comprehensive as possible. So please share your questions, experiences, and opinions. You can use the new gout forum or my help desk.

    Allopurinol Shelf Life References

    1. Day, Richard O., Garry G. Graham, Mark Hicks, Andrew J. McLachlan, Sophie L. Stocker, and Kenneth M. Williams. “Clinical pharmacokinetics and pharmacodynamics of allopurinol and oxypurinol.” Clinical pharmacokinetics 46, no. 8 (2007): 623-644.
    2. Alexander, Kenneth S., Nipun Davar, and Gordon A. Parker. “Stability of allopurinol suspension compounded from tablets.” International journal of pharmaceutical compounding 1, no. 2 (1997): 128-131.
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