Long-Term Opioid Therapy - What Are the Effects?
Most people who need to take opioids on a long-term basis for chronic noncancer pain are understandably concerned about what kind of effect it will have on them. Many have mistakenly believed that opioids destroy both the body and the brain - and possibly even shorten lives. Although pain management experts have long contended that opioid therapy is not dangerous when properly administered, until now there has been no actual research on long-term opioid use (10 years or more) to back them up.
Enter Forest Tennant, MD, who undertook a first-of-its-kind research study evaluating chronic pain patients who had been receiving opioid therapy for 10 to 35 years. The results of his study should be extremely encouraging for patients who need long-term opioid therapy as well as their doctors, some of whom may have been hesitant about it. Tennant concluded that the significant improvements in quality of life and physical functioning from opioid therapy are so positive they outweigh any negative complications, which can be easily managed.
Tennant's study looked at 16 female and 8 male chronic pain patients between 30 and 79 years of age. Their chronic pain conditions were:
Neuropathies and Arthropathies - 29.2%
Spinal Degeneration - 25%
Abdominal Adhesions or nNeuropathies - 20.8%
Fibromyalgia - 12.5%
Headache - 8.3%
Hip Necrosis -4.2%
The subjects had all been receiving continuous opioid therapy for 10 to 35 years.
All were taking a long-acting form of either morphine, oxycodone, fentanyl or methadone and one or more short-acting opioids for breakthrough pain or pain flares.
They all also took additional medications such as muscle relaxants, sleep aids, hormone replacements and dietary supplements.
Almost all of the patients (22 of 24) said their pain had permanently decreased over time. And the vast majority (20 of 24) felt their opioids still provided the same relief as when they started treatment. All of the patients reported one or more functions or activities they can do now that they couldn't do prior to beginning opioid therapy (i.e., get out of bed everyday, take walks, shop or visit friends).
Several new medical conditions developed in the group over the 10+ year period, such as hormone abnormalities, weight gain, tooth decay, tachicardia, hypertension, osteoporosis, hyperlipidemia, and diabetes. There was no clear way to determine whether these conditions were caused by the pain, the opioid therapy, the natural aging process, or were just inherent in the patients; however, all of the conditions could easily be medically managed.
All but one of the males in the study experienced lowered serum testosterone, a known complication of opioid therapy, which can be conrolled by hormone replacement therapy.
Notably, there were no neurologic complications including dementia, hyperalgesia, tremor or seizures. Nor were there any liver, kidney, or gastrointestinal complications, except for minor constipation.
Rather than causing serious health problems, Tennant suggests that because of the decrease in pain, opioids may actually allow or even promote neurologic healing. He goes on to suppose that opioid therapy may prevent a number of medical complications of pain and also may prevent early death due to the over-stimulation of the pituitary-adrenal-axis or possibly electrical stimulation produced by damaged nerves. Tennant acknowledges that this is a small study and states that much additional study is needed to determine cause and effect of medical conditions in opioid-maintained patients.
Finally, Tennant concludes, "Even though the number of patients evaluated here is relatively small, the great improvement in their quality of life and physical functioning is so positive and the complications of the therapy so easily managed that long-term opioid therapy should continue to be provided and evaluated."
Source: Tennant F. A 10-year evaluation of chronic pain patients treated with opioids. Heroin Addict Relat Clin Probl [Europad Journal]. 2009;11(1):31-34.