Where feasible, a physician with expertise in pain management and/or addiction can help select and implement the most appropriate care plan for CNCP patients who are addicted to opioids.
1. Options for Treatment
Three treatment options for the opioid-addicted patient with CNCP are:
- Methadone or buprenorphine treatment
- Structured opioid therapy
- Abstinence-based treatment
2. Treatment with Methadone and Buprenorphine
2.1. Methadone Treatment
1. Indications for methadone treatment are any of the following:
- a failed trial of structured opioid therapy
- using opioids by injection, snorting, or crushing tablets
- accessing opioids from multiple physicians or from the "street"
- addiction to opioids and to other drugs/substances, e.g., alcohol, cocaine
2. Methadone is effective for the treatment of opioid addiction in the presence of CNCP.
- Methadone maintenance treatment involves daily supervised dispensing, urine drug screening, and counseling.
- To obtain an exemption to prescribe methadone for opioid addiction, physicians should check with their provincial regulating body for direction.
- The patient should be expected to consent to open communication between the methadone provider and the primary-care physician (include in treatment agreement).
- Primary-care physicians and methadone providers should inform each other of newly diagnosed health conditions for the patient and long-term prescribing of other medications, particularly opioids and benzodiazepines.
2.2 Buprenorphine Treatment
1. Indications for buprenorphine treatment are similar to those for methadone treatment; buprenorphine treatment could be preferred over methadone for:
- patients who are at higher risk of methadone toxicity (e.g., elderly, benzodiazepine users)
- adolescents and young adults
- patients in communities where methadone treatment is unavailable.
2. Buprenorphine is a safe and effective treatment for patients with a dual diagnosis of CNCP and opioid addiction.
- Physicians should be aware of provincial regulatory guidelines regarding buprenorphine prescribing and training requirements.
- Buprenorphine (buprenorphine and buprenorphine-naloxone are being used interchangeably) is a partial mu opioid agonist with a long duration of action. It is a well-established treatment, with good supporting evidence for the treatment of opioid addiction (West 2000; Mattick 2008).
3. Structured Opioid Therapy (SOT)
Structured opioid therapy has been shown to improve outcomes in patients who have exhibited aberrant drug-related behaviours (see Recommendation 12). SOT is the use of opioids (other than methadone or buprenorphine) to treat CNCP with specific controls in place, including patient education, a written treatment agreement, agreed-on dispensing intervals, and frequent monitoring.
3.1 Indications for a Structured Opioid Therapy Trial
An ideal candidate for a SOT trial would be an opioid-addicted patient with CNCP who:
- Has a well-defined somatic or neuropathic pain condition for which opioids have been shown to be effective. (See Recommendation 4 for a review of evidence of opioid effectiveness.)
- Is well-known to the physician
- Is not currently addicted to cocaine, alcohol or other drugs
- Is not, to the physician’s knowledge, accessing opioids from other sources, injecting or crushing oral opioids, or diverting the opioid
3.2 Treatment Agreement Specifications
A written treatment agreement is strongly recommended. It should specify controls relating to prescribing and monitoring, and outline expectations of patient compliance with referral for consultation or treatment programs, e.g., pain management and/or addiction consultation or programs.
3.3 Opioid Selection and Prescribing
- It may be advisable to switch patients to a different opioid. (See Recommendation 13.)
- Avoid oxycodone and hydromorphone, if possible.
2. Dose: It is advisable to keep below 200 mg morphine equivalent.
3. Dispensing intervals: e.g., daily, bi-weekly or weekly dispensing interval, with no early prescription refills.
3.4 Monitoring Structured Opioid Therapy
Frequent monitoring is required; it could include:
- Urine drug screening (see Recommendation 3)
- Pill and patch count
- Evaluation for significant opioid effectiveness (i.e., improved function or at least 30% reduction in pain intensity, see Recommendation 9)
3.5 Failed Trial
If a) opioid effectiveness is not achieved, or b) the patient is not compliant, consider the SOT a failed trial. Taper and refer for opioid agonist treatment or abstinence-based treatment.
4. Abstinence-Based Treatment
- Abstinence-based treatment can be a patient preference or used when methadone or buprenorphine treatment is not available.
- Abstinence-based treatment begins with medically assisted withdrawal management, using clonidine, or tapering doses of methadone, buprenorphine or other opioids.
- This should be immediately followed by formal addiction treatment (inpatient or outpatient).
- Patients should be strongly cautioned that 1) they have lost their tolerance to opioids after as little as a week or two of abstinence, and 2) they are at risk for overdose if they relapse to their original opioid dose (Strang 2003).
R21. Summary of Peer-Reviewed Evidence
1. Structured opioid therapy has been shown to improve outcomes in patients who have exhibited aberrant drug-related behaviours.
Several observational studies have documented improved outcomes in patients receiving structured opioid therapy. In one study, 85 patients on opioids were referred to a primary-care, multidisciplinary disease management program operated by internists, pharmacists and a psychiatrist. Patients received monthly structured assessments, pain contracts, medication titration and monitoring for substance misuse. Twenty-seven patients (32%) were identified as misusers; 15 of these dropped out of the program because they were not prescribed opioids. Those who remained in the program improved pain, depression and disability scores (Chelminski 2005).
Wiedemer (2007) prospectively evaluated a structured opioid renewal clinic operated by a nurse practitioner and clinical pharmacist. About half of the 335 patients referred to the clinic had aberrant drug-related behaviours. The clinic used random urine drug screening, treatment agreements, frequent visits, and pill counts. Only small quantities were dispensed. Of the patients with aberrant baseline behaviours, 45% complied with the treatment agreement and their aberrant behaviours resolved, 38% dropped out of treatment, 13% were referred to addiction treatment, and 4% were weaned off opioids.
A retrospective evaluation of a clinic that performed careful adherence monitoring through urine drug screens and pill counts documented a 50% reduction in cases of opioid abuse (double doctoring or dealing), from 18% to 9% (Manchikanti 2006).
Currie et al. (2003) conducted an evaluation of an outpatient treatment program for 44 chronic pain patients, most of whom had opioid addiction. The clinic provided counseling and close medication supervision, with a tapering protocol using scheduled, long-acting opioids. Half the patients were able to taper completely off opioids and most were able to reduce their opioids (Currie 2003). The patients reported improvements in pain and mood.
These studies suggest that structured opioid therapy can result in increased compliance with the treatment agreement and increased referrals for addiction treatment. These results are promising but the evidence in support of structured opioid therapy is not as strong as the supporting evidence for buprenorphine and methadone therapy for opioid addiction. Also, the clinics using structured opioid therapy were well staffed by nurse practitioners, pharmacists and therapists; it might be difficult for primary-care physicians to undertake this form of treatment. Therefore, we suggest that structured opioid therapy be reserved for patients who meet the criteria listed above – unlikely to be accessing opioids from other sources, altering the route of delivery or diverting.
2. Methadone is effective for the treatment of opioid addiction in patients with CNCP.
Farre et al. conducted a meta-analysis of 13 randomized, double-blinded trials. They showed that higher doses of methadone were more effective than low doses in reduction of illicit opioid use. They concluded that oral methadone at doses of 50 mg/day or higher is the drug of choice for opioid addiction (Farre 2002).
One study found that methadone patients with opioid addiction who also had pain (n=103) had similar substance-related outcomes to those methadone patients in the group without significant pain (n=97). Compared to patients who did not report pain at baseline, patients with pain showed similar reductions in heroin, alcohol, cocaine and illicit prescription sedative use and greater reductions in illicit prescription opioid use. At 1-year follow-up, there was no significant difference in past 30 day use of heroin, cocaine, alcohol, illicit prescription sedative or opioid use between patients with and without pain at baseline (Ilgen 2006).
3. Patients who “successfully” completed inpatient detoxification were more likely than other patients to have died within a year. The explanation may be loss of tolerance.
Strang et al. followed up patients who received inpatient opiate detoxification, and looked for evidence of increased mortality, and investigated the distinctive characteristics of patients who died. To test whether loss of tolerance increased the risk of overdose, they grouped the patients into three categories, according to their opiate tolerance at the point of leaving treatment: 43 “still tolerant” (ST) patients who failed to complete detoxification; 57 “reduced tolerance” (RT) patients who completed the prescribed phase of detoxification but who prematurely left the treatment program; and 37 “lost tolerance” (LT) patients who completed the detoxification and also completed the inpatient treatment program. The three overdose deaths that occurred within four months after treatment were all from the LT group; the two deaths unrelated to overdose (although both these patients had relapsed) were one LT patient with end stage renal failure and one RT patient with Clostridium welchii infection; no deaths occurred in the ST group (Strang 2003).
4. Buprenorphine is a safe and effective treatment for patients with a dual diagnosis of CNCP and opioid addiction.
A review study found that there was some evidence for the use of buprenorphine in the treatment of CNCP (it largely reviewed trials that used the transdermal preparation) and that it was well tolerated in elderly patients (Johnson 2005).
Myers et al. 2005 state that the “introduction of buprenorphine management has the potential to greatly improve the treatment of chronic pain in patients with a history of addiction to opioids or with a family history of addictive disorders” (Myers 2005).
5. There is evidence from several studies for the safety and effectiveness of buprenorphine use in primary care.
Controlled trials have demonstrated that buprenorphine maintenance treatment is safe and effective when prescribed in primary care settings (O'Connor 1998, Fiellin 2002, Caplehorn 2003, Gibson 2003, Lintzeris 2004, Simoens 2005, Stein 2005, Barry 2007, Mintzer 2007, Moore 2007). Physicians providing office-based opioid agonist treatment report high levels of satisfaction, although they would like better access to counseling and other social services (Becker 2006).