Methadone Overdoses Due To Flawed Conversion Calculations

Are Flawed Dose Conversion Calculators to Blame for the Dramatic Increase in the Number of Methadone Overdoses?

Jeffrey Fudin, PharmD, said that evidence published in an article in Pain Medicine in 2012 “suggests that the use of dose conversion ratios published in equianalgesic tables may lead to fatal or near-fatal opioid overdoses.”

He said opioid rotation is common in clinical practice for several reasons. For example, opioids may be switched when pain is not under control and doses cannot be escalated, when adverse events or toxicity occurs, when patients develop rapid tolerance, or when opioid-induced hyperalgesia is suspected.

Specifically in chronic pain patients, opioid rotation is reported to offer better pain control, and due to patient differences, opioid rotation may be required to find the best fit.

Opioid conversion doses can be found in package inserts, primary literature, textbooks, websites, and online calculators.

Fudin and his team found eight online opioid conversion calculators

When the remaining calculators were compared to each other, a +242% variation in recommended methadone does was seen in the results. A positive variation carries a risk of overdose and death, while a negative variation carries a risk of underdose and withdrawal, Fudin explained. He also reported a +100% variation for fentanyl.

Fudin has also studied the top mathematical models for calculating opioid conversion doses, and he has developed his own formula using the most conservative approach

Fudin’s formula has now been incorporated into the online calculator that is available on the Practical Pain Management website.

Slow titration, clinical judgment, and individualization of treatment are necessary to safely and effectively switch a patient from one or more opioids to another,” Fudin concluded.

Although methadone accounts for only 2 percent of opioid prescriptions, it caused nearly one in three prescription opioid overdose deaths in 2012

In my experience, methadone feels categorically different than the more common opiates used for pain management, like oxycodone and hydrocodone.  More addictive than all other opioids (even heroin), dependence sets in quickly.

Methadone seems to be not only more potent, but also to develop a stronger grip on a person (I don’t know how else to describe it) so that a slight delay or decrease in dosage immediately triggers withdrawals.  This opiate scared me.



5 thoughts on “Methadone Overdoses Due To Flawed Conversion Calculations

  1. DREW5000G

    We know it to be stronger than gear(heroin) over the pond. I always tried to use as little as possible as i had heard the stories about it being hard to kick and that it gets in your bones. Always got the sugar free version because it rots your teeth. As soon as subutex came out we had to reduce to 20 mls of meth to b e able to switch so i did that immediately.Never took methadone again.


    1. Zyp Czyk Post author

      It’s interesting to me that so many people taking it for different reasons have the feeling that methadone is dangerous, yet it doesn’t seem to be chemically much different from the rest of the opioids. When even experienced drug users are afraid of a “medication” that’s supposedly so much safer than heroin or oxy, something is wrong.

      It seems odd that both addicts and pain patients dislike this medication on a gut level, without being able to explain exactly why. I’d be willing to wager that sometime in the next decade or two, scientists will discover what it is about methadone that scares us away from it.


  2. Painkills2

    “Specifically in chronic pain patients, opioid rotation is reported to offer better pain control, and due to patient differences, opioid rotation may be required to find the best fit.”

    Not mentioned is the fact that insurance companies require patients to try certain medications first before approving others. And for medical cannabis, many states require pain patients to have tried all other “standard” treatments and medications before allowing entry into the program. Along with MRIs and other tests required to “prove” your medical condition, it’s really expensive to find your way to the best treatment.

    As for methadone — I took it a long time ago, and I remember that it didn’t help with the pain. And increased dosages only caused increased side effects.

    I know a lot of pain doctors began prescribing methadone because it was so much cheaper than other opioids. And because methadone didn’t always have such a bad reputation with the DEA, so doctors didn’t fear prescribing it as much as other drugs. Of course, this caused doctors to over-prescribe methadone, and so now you see more abuse.

    When you’re sitting in the examining room with your doctor and a nurse, the DEA and all their friends in State Medical Boards are also there, along with your insurance carrier. (And if you’re in a Catholic hospital network, religion is there too.) Now, who gets to make your medical decisions?


      1. Painkills2

        Sure, I have all kinds of important and influential friends… We have frequent tea parties, where we discuss how hard it is for poor people these days. :D



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