Observations on Prescribed Drugs for Pain Patients

The CLSI (Clinical Laboratory Standards Institute) has proposed a list of drugs that should be tested for their presence to ensure patient compliance with their pain medications [1]. We wished to compare the CLSI recommendations with our observed positive drug tests in this population. We offer a panel of 80 drugs and metabolites in our definitive urine drug test [2]. For this analysis we matched the medical practice designation with the drugs observed by urine drug testing. The data is from our laboratory which performs drug testing for pain clinics and rehabilitation centres. This correlation should result in a good indicator of the drugs used in the medical practice of treating these patients. The CLSI recommendations and our observations should correlate.

Permission to perform the study was granted from WCG IRB WCG IRB, 1019 39th Ave., SE Suite 120, Puyallup, WA 98374, USA. The patient population was selected from those medical practices designated as pain medicine [3,4]. This included pain/ortho, pain management, primary care pain, internal medicine, primary family medicine, pain orthopedics, physical medicine and pain, sports medicine.

The laboratory tested 611,329 specimens from 2016 to 2022. The method of analysis was that of Krock K, et al. [3]. The computational methods and data storage were that of Pesce AJ, et al. [2]. The medical practice designations were obtained from our billing information. The calculation of observed frequency was based on the number of times that drug was observed in the years 2020 to 2022.

The tier 1 drugs in the CLSI document that we test for are Amphetamine, Methamphetamine, Methylenedioxymethamphetamine (MDMA), Methylenedioxyamphetamine (MDA), Methylenedioxyethylamphetamine, (MDEA), Phenobarbital, Alprazolam, Clonazepam, Diazepam, Lorazepam, Oxazepam, Temazepam, Benzoylecgonine, Δ9-tetrahydrocannabinol (THC), 6-acetylmorphine (6-AM), Buprenorphine, Codeine, Fentanyl, Hydrocodone, Hydromorphone, Morphine, Oxycodone, Oxymorphone, Tapentadol, and Tramadol. Not included in the CLSI document are the metabolites norhydrocodone, noroxycodone, 7-aminoclonazepam, alpha-hydroxyalprazolam, o-desmethyl tramadol, and norbuprenorphine which are used to indicate that the patients are taking the prescribed drug.

For the pain medication patients, the observed drug positive finding for each medication is tabulated in Table 1. The list is truncated at forty-six observations. The lowest frequency is about 2.5% of the most prevalent treating drug, hydromorphone, The next most prevalent was oxycodone. Hydrocodone was the third most prevalent. The oxymorphone frequency was due to its role as a metabolite of oxycodone as well as being a separate prescribed drug. Gabapentin was also prevalent as a pain medication. The illicit drug fentanyl was present in less than 10% of our observations. However, THCA was present in about 25% of our positive specimens.

Table 1:Pain Management testing, From CLSI Table 8: Tiers of drug testing.

The drug propoxyphene was observed infrequently as this has been removed by the FDA as a prescription drug. However, alcohol use must be considered in pain management testing. In this case about 23% of the positive specimens were positive for the alcohol use maker ethyl sulfate.

For the pain medications we expected hydrocodone to be the most prevalent prescribed drug as this was the most prescribed opiate in the general population.

There are a number of available surveys showing the most prescribed drugs in the US population. These are Vitamin D, Amoxicillin, Levothyroxine, Lisinoprill, Ibuprofen, Amphetamine/ dextroamphetamine, Amlodipine, Albuterol HFA, Prednisone, and Gabapentin [5]. These observations are based on population prescribing information and may not reflect what drugs are being prescribed for specific medical conditions. It is possible to establish specific drugs used to treat medical conditions by examining the medical practices. Pain management is somewhat unique because most of the patients undergo urine drug testing. We decided to examine the drug treatment of patients being given medications for pain management. We postulate that the information of drug test results may constitute a more accurate estimation of the actual patient’s use of their prescriptions but may also reveal nonprescription drug use.

We chose to examine the presence of this drug and other opiates in pain management medical practices.

Results

In this study, hydrocodone was the most prescribed opiate. One of the reasons for performing medical urine drug tests is to determine if the patient is taking other non-prescribed drugs. For the pain treated patients the most observed drug was hydromorphone, this is a metabolite of hydrocodone, and morphine as well as a prescription drug. The incidence of illicit drug use was significant (about10%) However the use of alcohol as measured by the frequency of positive ETS in specimens was about 23% far greater than any other non-prescribed drug. We observed drugs not listed in the CLSI guidelines which included mitragynine, methylphenidate, fluoxetine, bupropion, meperidine, 6-betanaltrexol, naltrexone, naloxone, zolpidem, and phentermine.

Our study was limited to the opiate drugs, hydrocodone, oxycodone, morphine, and the opiate agonists, methadone, buprenorphine. We also tested for the illicit drugs heroin, fentanyl, cocaine, and THCA.

The major drugs found were opiates showing compliance, however, alcohol use was prevalent, but the incidence of illicit drug use was low.

All the authors are employees of Precision Diagnostics LLC.

There are no conflicts of interest.

1. Catherine A, Hammett-Stabler (2018) C63 Laboratory Support for Pain Management Programs. 1^st ISBN: 978-1-68440-002-7, C63Ed1: 74.
2. Pesce AJ, Chandler N., Ackerman G (2021) Information Technology Structure for Urine Drug Testing Reports. 21ST Century Pathology 1(1): 103.
3. Krock K, Pesce A, Ritz D, Thomas R, Cua A, et al. (2017) Lower Cutoff for LC-MS/MS Urine Drug Testing Indicates Better Patient Compliance. Pain Physician 20(7): E1107-E1113.
4. Pesce A, Sundyhanata R, Ritz D, Thomas R, Ackerman G, and Bollman K Effects of a Pandemic and Isolation on Alcohol and Psychoactive Medication Use in a Population of Rehabilitation and Pain Patients. Ann Clin Lab Sci 51(5): 694-697.
5. The 50 most-filled prescriptions of 2022. Single Care.