I’ll share an interesting story about the data used for the prescription drug database in Wisconsin and other states. I’ve been holding back on writing about this issue in hopes that the reason for the story would be corrected, and I would have no story to tell. But that hasn’t happened. Brandeis and CDC made wrong calculations on buprenorphine PDMP Data.
A new law in Wisconsin requires all prescribers to check the prescription drug database when prescribing any controlled substance. I’m surprised that no privacy advocates have complained about the database, which tells prescribers about the controlled substances used by their patients over the past 5 years, the pharmacies their patients used, and any suspicions of law enforcement about their patient in regard to controlled substances. The database, or PDMP, is a significant tool for preventing doctor-shopping and diversion. But the PDMP provides a great deal of information about activities by patients that they rightfully believed to be private just a few years ago.
But this story isn’t about privacy. I’ll leave that for another day. This story is about the information provided by experts at the CDC, the top health agency in the world, about buprenorphine. A mountain of nonsense about buprenorphine permeates healthcare, law enforcement agencies, and addiction treatment programs. But one could optimistically expect the CDC to get it right. Right?
When a prescriber follows the new law and looks up a patient on the PDMP, the web page includes a graph that displays the patient’s use of opioids over the past three months, displayed as the oral morphine equivalence. The graph has a blue line on the graph that represents 50 mg of oral morphine per day, and a red line that represents 90 mg of morphine per day. Another line represents the patient’s daily opioid dose, and the entire graph is shaded red during the time that the patient also used benzodiazepines. Neat!
For most patients, the red and blue lines are clearly visible, and the patient’s opioid use is displayed in relation to those lines. But for patients on buprenorphine, the red and blue lines are pushed against the bottom of the graph by the line that shows the patient’s opioid usage. Why? Because according to the PDMP, a patient on 16 mg of a buprenorphine medication is taking the equivalent of 900 mg of morphine per day!
Anyone with a basic understanding of buprenorphine knows about the ceiling effect of the drug. Unlike with opioid agonists, the opioid potency of addiction-sized dosages of buprenorphine cannot be directly extrapolated from the potency at lower dosages. With oxycodone, 10 mg of the drug is ten times stronger than 1 mg of the drug. With buprenorphine, 2 mg of the drug is about as potent as 8 mg, which is about as potent as 24 mg. The PDMP, though, shows 16 mg of buprenorphine to be 16 times stronger than 1 mg of buprenorphine.
When I noticed the error in the data I emailed the people who developed the Wisconsin PDMP. They responded and wrote that they appreciated the information, but Brandeis University provided the data about opioid dose equivalency, so Brandeis was responsible for the accuracy (or lack of accuracy) of the data.
So I wrote to the folks at Brandeis who provided the information for Wisconsin and other states’ PDMPs. They responded that THEIR information comes from the CDC, and so the CDC was ultimately responsible for the dosage conversion data. They also said that doctors shouldn’t use the information for opioid dose conversions, and there was no danger to that effect because of the fine print at the bottom telling doctors to avoid using the information in that way.
I wrote to the CDC, cc’ing everyone and their cousins to make certain that the right person received my email. I wrote, respectfully, what I’ve written here—that the information about buprenorphine failed to take the ceiling effect into account, and that the misinformation could potentially lead to patient harm, if a doctor did what doctors tend to do, i.e. use the most readily available information about dose equivalency and trust that information, especially if it comes from an official site like their state’s Prescription Drug Database.
The CDC replied with a form-email. Given that a genuine response takes about one minute, I can’t believe that the person who received my email saved a significant amount of time by searching out that reply, but I suppose we citizens would become spoiled if the government responded personally! The form email thanked me for my interest in the CDC, and provided a link where I could read more about the great work they do.
I admit that I get worked up about things sometimes. And yes, I was annoyed to get a form email providing a link to more information from the CDC, after writing to correct their wrong information. So I sent an email expressing that annoyance to everyone in the story up to this point. I’m sure that at least a few of the people in the ‘to’ box had a good laugh, and I suspect that I annoyed a few more. Whatever.
A couple weeks later I noticed a new paragraph under the dose-equivalence graph, telling doctors to avoid using the opioid dose-conversion information to actually convert opioid dosages. The small print at the bottom of the page was made larger, and placed higher in the page, directly below the display of morphine equivalents. I don’t know if the change had anything to do with my emails or was only a coincidence.
But then yesterday I received an email from one of my patients, after he consulted with his surgeon about an upcoming operation. The patient wrote about that doctor, paraphrasing a bit: “she showed me a graph that said my tolerance is equal to 900 mg of morphine. I don’t know what that means exactly but she will need to give me a high dose of pain medicine without killing me.” I eventually spoke with that doctor. Guess where the graph came from?!
This the punchline by the way, in case you’re skimming the story. The patient wrote that his doctor used the PDMP to convert the amount of morphine he would need after surgery, in spite of the ‘warning’ on the web site. What a shock!
I shared my patient’s email with the people at the WI PDMP, Brandeis University, and the CDC, letting them know that even though they added a paragraph to their data telling doctors that their data was nonsense, doctors STILL used that data in a way that could kill somebody.
Should they be proud of that misplaced trust? I have no idea. But why don’t they just USE THE CORRECT DATA??!!