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7 Articles in Volume 5, Issue #7
Bioethics and Intractable Pain
Childhood Costochondritis and Biofeedback
Chronic Pain and Biopsychosocial Disorders
Head Region Neuropathies
Physical Therapy in Pain Management
Tennant Blood Study: Preliminary Report
Treating Muscular Dysfunction of Lower Limbs

Tennant Blood Study: Preliminary Report

Many physicians throughout the United States have begun therapeutic blood monitoring of chronic pain patients who require opioids. The motivations for this endeavor are multiple:

1. Monitor compliance with prescribed opioids;
2. Determine if tolerance and an adequate level of opioids are present in the blood to control pain;
3. Determine if the opioid dosage is appropriate since some patients malabsorb or too rapidly metabolize opioids.

Two major problems have emerged involving opioid blood levels. The standard published ranges of blood levels for opioids—originally established for non-tolerant, acute pain patients suffering, for example, from post-operative or dental pain—are erroneously being applied to tolerant, chronic pain patients. Table 1, a reference, depicts the published blood levels for non-tolerant patients and can be compared to collected data of this study. To control pain, many opioid-tolerant, severe chronic pain patients may require significantly higher daily opioid dosages for a lifetime. Second, some physicians have been accused of inducing an overdose death strictly based on a high opioid blood level taken at autopsy when, in fact, the patient was tolerant and required the high blood level for adequate pain relief. Death, in fact, was likely due to a cardiovascular or other adverse event.

To resolve these problems and enhance pain care, Practical Pain Management journal has asked a group of physicians to send us blood levels on their chronic pain patients who take opioids. We have chosen to publish preliminary survey results to provide at least some objective clinical data to guide physicians in improving their clinical care and protecting themselves from unscientific claims. Additionally, when completed in mid-2006, this survey will be made available to enforcement agencies, the legal community, state medical boards, and others who need to understand the scientific metabolism and pharmacology of chronic opioid administration.

Be clearly advised that this survey is not meant to determine optimal testing methodology or therapeutic agent. Physicians participating in this survey selected their own local, commercial laboratory resource. While we have requested that opioid blood levels be optimally done two hours post dose, there is no assurance of this time frame. Also, the survey asked for daily opioid dosage and simple patient functions rated simply as fully functional, able to drive, and/or able to work or volunteer. Full functionality is generally characterized as patients being ambulatory and able to bathe, feed, and clothe themselves.
Many physicians have related to us that the lack of data involving blood levels in high dose opioid patients is essentially at a crisis level, given the large number of physicians who have been falsely accused of wrongdoing. Consequently, we present here preliminary data. This data is preliminary only in the sense that the first batch of cases received are presented herein. Many more cases have been received and will be entered into these Tables and published in upcoming issues of PPM. Experienced intractable pain physicians will find no surprises in these reported levels of opioids required for pain relief and restoration of functionality to chronic, severe pain patients.

This study’s results, presented here and in the future, will be summarized by opioid. Within the next six months we will compile all data into a ready-to-use reference. In all cases, the titration instructions for each respective opioid must be followed carefully to ensure safety and efficacy.

We invite comments and experiences with opioid blood levels.

Special thanks to Dr. Lawrence Probes for his assistance in compiling the data.


1. Baselt RC. Disposition of Toxic Drugs and Chemicals in Man, 5th Ed. Chemical Toxicology Institute. Foster City, California, 2000.
2. Goldman L and Ausiells D. Reference Intervals and Laboratory Values in Cecil Textbook of Medicine, 22 ed. Eds, Saunders, Philadelphia, 2004.

Please refer to the Nov/Dec 2005 issue for the complete text. In the event you need to order a back issue, please click here.

Last updated on: January 7, 2021
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