Treating the Opioid-addicted Chronic Pain Patient: The Role of Suboxone
Chronic pain and addiction are frequent comorbidities, creating a therapeutic dilemma for many pain specialists. A recent small-scale trial indicated that approximately one-third of chronic pain patients may have an addictive disorder.1 In addition the non-medical use of opioids is an ever-escalating concern, with reports that about 5% of the population are abusing opioids, including 11.4% of youths aged 12 to 25 years.2 Patients with opioid addiction report chronic pain quite commonly and may present with chronic pain symptoms due to sympathetic arousal, sleep disorders, increased risk for trauma, increased tolerance, and increased stress with hippocampus-pituitary-adrenal axis activation.3
A patient with chronic pain and addiction is also at increased risk for overdose.4,5 The reasons for this are complex and include an increased tolerance to opioids, opioid craving related to addiction, the use of opioids to self-medicate concomitant psychological symptoms, and the impact of withdrawal from all addictive substances on worsening chronic pain syndromes.
Risk Stratification: Identifying High-risk Patients
It is recommended that all pain patients be screened for psychological comorbidities before prescribing medical therapy. Screening for addiction risk, however, can be difficult as the hallmark of the disease is denial of the consequences of addiction on an individual’s life.6 I recommend two screening tests that require minimal training and fewer than 2 minutes to administer in the office. They are the CAGE (adapted to include drugs) and the Drug Abuse Screening Test (DAST).7,8 In addition, the Webster and Webster Opioid Risk Tool (ORT) and the Revised Screener and Opioid Assessment for Patients with Pain (SOAPP-R) are two easy-to-use tools that can help identify risk of opioid medication misuse (Table 1).9,10 Appropriate screening with history, physical examination, and urine drug testing can help make a determination ahead of time regarding what the relative risk (risk stratification) of most patients is to develop an opioid-related adverse event if opioids are prescribed.
Pain Patients Already on Opioids
Unfortunately, many physicians find themselves in a situation where they are seeing chronic pain patients already on opioid therapy with addiction problems. We now understand that these patients are not only at highest risk for overdose and diversion, but they are the least likely to improve function while on an opioid, especially if the opioid is the primary form of pain treatment.11,12
While identifying patients with addiction problems and referring them for appropriate addiction treatment is ideal, this is frequently a diagnosis that may require a number of visits and difficult decisions concerning suitable chronic pain treatment. However, it is important to set a structure in your practice that minimizes risks for all patients. As noted, it is important to take a careful medical history, including substance abuse history, as well as perform a medical evaluation (Table 2).13
Currently, there are no high-quality studies regarding the percent of patients treated with opioid pain medications who developed de novo opioid addiction or dependence. One of the questions most frequently asked is concerning the role of Suboxone (buprenorphine/naloxone) in this setting.14 Patients requesting Suboxone therapy for opioid addiction or dependence may be using opioids without a prescription, prescription opioids alone, or both. For patients on prescription opioids, problems with addiction may have predated their use of prescription medications or began only after starting therapy with prescription opioids. While asking about a previous history of addiction and alcohol problems is important, it may be difficult to determine the extent of the patient’s previous problems with opioids prior to their difficulties with prescription medications. This is frequently addressed during addiction treatment as relapse prevention strategies are reviewed and underscore the importance of concomitant addiction treatment during Suboxone therapy.
Suboxone for Addiction
Suboxone was first approved in 2002 for the treatment of opioid addiction, but not chronic pain. Prior to its approval, opioid addiction was most commonly treated with methadone. Methadone can be dispensed only in a limited number of clinics that specialize in addiction treatment. According to the FDA, “There are not enough addiction treatment centers to help all patients seeking treatment—therefore, Suboxone was the first opioid available under the Drug Abuse Treatment Act of 2000 for the treatment of [opioid] dependence that can be prescribed in a doctor’s office.”
Suboxone contains buprenorphine and naloxone. Buprenorphine is an opioid partial agonist with high affinity for the µ and κ receptors that is effective at preventing opioid withdrawal and cravings while the patient participates in addiction treatment. Naloxone, an opioid antagonist, was added to guard against misuse. Suboxone is currently available as a sublingual film. The half-life of buprenorphine is 24 to 60 hours, making daily or every other daily dosing possible when used for treatment of opioid addiction (Table 3).15 Table 4 lists possible drug–drug interactions with Suboxone.15
Suboxone was specially formulated to help curb abuse. For example, there is a ceiling effect of Suboxone and taking >16 to 32 mg per day will not result in any further positive drug effects and in fact may precipitate withdrawal. If injected, Suboxone produces severe withdrawal symptoms, but no adverse effects when taken orally as prescribed. In addition, taking other opioids while on Suboxone may also precipitate withdrawal. This gives the medication less risk of abuse and side effects than full opioid agonists.
However, the risks of side effects of Suboxone dramatically increase when it is used with alcohol, benzodiazepines, and illicit drugs.13 This makes Suboxone therapy for patients with polysubstance abuse an increased challenge, as it is important to continue to monitor and address any aberrant drug-taking behavior. As noted, patients on benzodiazepine therapy will have increased risk of adverse outcomes if Suboxone is used. For this reason, patients with opioid addiction as part of a polysubstance abuse diagnosis and those on benzodiazepines may not be appropriate candidates for Suboxone or may need a residential or in-patient evaluation before a decision is made about whether to use Suboxone. At the very least, intensive outpatient therapy and careful monitoring will be very important to ensure safety and management of withdrawal symptoms (Table 5).