Quantitative Urine Drug Testing and Buprenorphine: Tainted Motives?

First Posted 11/23/2013

As fear of buprenorphine diversion sweeps the nation, some states have passed legislation adding more rules for practices that treat addiction using buprenorphine.    Never mind that buprenorphine is linked to about 400 deaths over ten years, one tenth of the number of deaths from acetaminophen during that same time, and 0.1% of the number of overdose deaths overall.

Many parts of the country have seen a reduction in number of buprenorphine-certified physicians over the past few years.  Many rural areas have no buprenorphine prescribers at all.  The lack of prescribers, combined with the limit of 100 patients per prescriber, leaves opioid addicts with one legitimate treatment option— the early morning line for methadone or buprenorphine at methadone clinics.  I’m not against the clinics, but the need to report each morning is a significant barrier to employment in many patients who would do just as well with a prescription for the medication—and a first-shift job. Their other option is to do what all the news stories have been reporting—use buprenorphine without a doctor’s supervision and attempt to stop heroin or pain pills on their own, aka diversion.

I’ll leave it to reporters with staff to list the states that have become doctors at this point.  One clue about your own state is whether your doctor is still prescribing buprenorphine products, or has instead moved to an area of medicine where doctors make decisions according to clinical judgment.  As the number of buprenorphine/naloxone prescribers in my part of the country has decreased, the amount of diversion has increased.  I predict that policies that discourage doctors from treating opioid dependence will increase the number of addicted people trying to treat themselves.

Sometimes it is easy to predict unintended consequences.

Regulatory agencies of at least one state prevent insurers from covering specific, FDA-approved medications.  Other states require doctors to follow specific practice patterns instead of their best clinical judgment.  One example of oversight that demonstrates the folly of lawmakers playing doctor is the push to require ‘quantitative urine testing’ in all patients at frequencies determined at the state capital, rather than by the doctors treating the patients.  The expectation is for quantitative testing to reduce diversion.  Note that 30,000 overdose deaths per year from non-buprenorphine products never prompted such oversight, nor did the well-known ‘pill-mill’ pain clinics that have flourished for the past decade.  But an average of 40 deaths per year related to buprenorphine has demanded action by lawmakers!

There are times when quantitative testing is useful, but I suspect that legislators who voted to require such testing heard only the half of the story told by people with vested interests.  After all, quantitative testing is one of the more lucrative areas in all of healthcare.  Even Medicaid agencies that pay pennies on the dollar for office visits pay generously for testing with the right billing codes.  Turn-key testing businesses can be purchased by entrepreneurial doctors to grow revenue at pain clinics, leasing out testing equipment and training techs in return for a piece of the action.

What legislators SHOULD know:

Quantitative urine tests for standard drugs of abuse in just one patient can cost well over $1000.  Costs over $500 per test are the norm.  The costs are paid by insurers, Medicaid, or patients, increasing insurance premiums and taxes and blocking treatment for some patients.

‘Point of care’ test strips that use immunoassay methodology are sensitive and accurate.  A standard test kit shows the presence/absence of trace amounts of specific opioids (methadone, oxycodone, or heroin/morphine derivatives), amphetamine, benzodiazepines, cannabinoids, cocaine, PCP, barbiturates, and buprenorphine.  Typical test kits give all the results for a total price of $5-$10.

Almost all the decisions related to testing rely on the presence or absence of substances—not the number of nanograms of a substance.   The point is whether a patient used heroin or cocaine—not how many milligrams of heroin or cocaine were used.  Test companies claim that measurement of buprenorphine’s first breakdown product, norbuprenorphine, can determine if a patient took buprenorphine only recently to fool the doctor. But I receive dozens of emails each year from patients with nothing to gain by describing their experience in those cases, swearing that they were taking the medication correctly, and asking how they can prove their truthfulness after what is called ‘flipped levels’ in such testing.  Besides, anyone with knowledge of addiction knows how difficult it would be to pull of such a scam. The scammer’s urine would still contain the drug of abuse, unless we suppose the unlikely scenario where scammers successfully stop all opioids for a week each month and experience withdrawal each time, all for the sake of a script for Suboxone.  Beyond the misery, few addicts would be able to control use of narcotics to that extent.  That’s why they are addicted in the first place!

‘Quantitative urine testing’ measures the concentrations of substances in a patient’s urine.   But urine concentrations of substances are not accurate reflections of blood concentrations of the substances.  The first part of kidneys (the glomeruli) act like sieves with very large pores, spilling gallons of dilute liquid that contains drug metabolites and other molecules.  The largest parts of our kidneys consist of tubules that reabsorb water and reabsorb or secrete other molecules and ions.  When that liquid finally reaches the exit from the kidneys at the ureters, the original filtrate has been concentrated by several orders of magnitude, and has had a range of molecules removed from or secreted into it.  Water reabsorption depends on hydration status, circadian rhythms, diuretic and other medications, stress hormones, diet, and other factors.  As a result, concentration of a substance in the urine is not related to concentration in the blood—let alone to the use of the substance.  Blood levels provide far-more-accurate information, but even blood levels vary from differences in metabolism of substances between individuals.

Quantitative testing tries to overcome the gap between blood and urine levels by using levels of other substances, such as creatinine or urea, to estimate the extent of concentration performed by the kidneys.  But there are enough variables to make the results far from reliable.  But frankly, the inaccuracies don’t really matter—since in most cases the presence or absence of a chemical is the issue, not the concentration.

In an era when costs are a concern, why would states become involved in testing processes that force a dramatic increase in treatment costs?   Doctors who know their patients are in better position to decide when such testing is valuable.   In medical school 25 years ago, I learned about the inefficiency of shotgun approaches to lab testing—that instead of ordering routine chemistry panels for every patient, doctors should decide which specific tests are necessary and order accordingly.  To mandate such expensive testing, someone is deciding ‘yes that’s true, but….’.   The annual climb in the cost of healthcare is largely due to those and other ‘buts.’

The only reason the state would think that they know better—from hundreds of miles away, without meeting the patients—is if they assume that doctors treating addiction don’t care what their patients are doing, or are inept.  But if the same inept doctors are the people interpreting the results of mandated quantitative testing, what does the mandate add, exactly?  And why the selective oversight of doctors who treat addiction, when most of the harm from drug diversion comes from opioid agonists prescribed by doctors who don’t work in the addiction field?

Other mandates include the rules found on standard opioid treatment contracts.  The rules themselves are not unreasonable.   But I take issue with the double standard applied to addiction physicians.  Expensive residential treatment programs have abysmal success rates.  Should they be regulated?   People who have too much plastic surgery look ridiculous—should that be regulated?  Everybody talks about the epidemic of opioid overdose deaths— deaths caused 99.9% of the time by something other than buprenorphine, the most effective treatment for opioid dependence.  But it’s buprenorphine that needs regulating?