Structuring Opioid Therapy
As analgesics, opioids are without equal, cutting most types of pain, on average, by at least 30 percent.1 However, opioids are not a panacea and confer significant risks to patients in addition to benefits. Opioid therapy for chronic pain has the best chance for success when treating clinicians take steps to maximize safety and support appropriate use.
Three common sources of risk are 1) patient difficulty in managing opioid use, 2) the potential worsening of sleep-disordered breathing, and 3) dosing that leads to respiratory depression—particularly when methadone is prescribed or consumed for pain by people unfamiliar with its special properties.
The neurobiological disease of addiction is not synonymous with drug abuse, which can have numerous causes; however, any problem a patient manifests in managing opioid intake is likely to damage the integrity of pain therapy if not dealt a swift and suitable solution. Because true opioid addiction affects only about 1% of the general population2 and up to perhaps 5% of the chronic-pain population (see Figure 1), it is clear that most people who take medications for pain will not become addicted to them. Difficulties in managing opioid intake that stem from causes other than addiction are common, however. Figure 1 illustrates the relationships and frequency of aberrant behavior, abuse, and addiction documented in the author’s pain practice. Although 40% of the patients displayed at least one aberrant behavior associated with medication misuse within one year, only 20% of the patients met a diagnosis of drug abuse and still fewer (2-5%) met the diagnosis for opioid addiction. It could be said that all addicted people, then, are abusers, but not all abusers are addicted. Furthermore, aberrant behavior only rises to the level of drug abuse about half the time and is even more seldom a sign of the disease of addiction.
These delineations help the clinician choose the right monitoring guidelines because, as motivations for abuse differ, so will the clinician’s response in intensifying monitoring measures. Drug abuse and the comorbid conditions that sometimes give rise to it must be addressed in tandem with pain therapy or the pain therapy has little chance of success.
Management takes place by initiating a structure for prescribing opioids that contains the following components:
- All patients to be prescribed opioids for pain must undergo assessment prior to beginning opioid therapy to determine their level of risk for drug abuse.
- Once the assessment is complete, patients should be stratified according to risk level.
- Patients are then monitored according to risk level using “proactive," rather than “reactive," strategies.3
- Patients’ treatment plans and goals are reassessed frequently, adjusted as needed, and documented thoroughly.
Assessment and Risk Stratification
Several opioid-specific assessments are available for clinical use, including the Opioid Risk Tool (ORT)4 and the Screener and Opioid Assessment for People with Pain (SOAPP),5 as well as several non-opioid-specific tools that can be adapted. Tools to assess for current or potential substance abuse utilize risk factors for abuse such as age, personal or family histories of substance abuse, past sexual abuse, the presence of complicating mental disorders, smoking status, and prior problems with the law, to name a few. Assessment for drug-abuse potential should be routine for every patient seeking opioid therapy to treat chronic pain. Opioid-specific tools that have been validated in pain populations and that have predictive value are preferred, but clinicians must choose a template that fits with their own clinical situation that considers the time available, access to expertise, and preference for self-administered or interview tools. Perhaps more important than the choice of tools is the consistent action of performing and thoroughly documenting some type of assessment that combines the best available assortment of questions supported by the literature and clinical experience.
Assessing patients gives clinicians the information needed to stratify patients according to abuse risk; typically, abuse risk can be classified as high, moderate, or low. Low-risk patients, for example, tend to have mild-to-moderate pain, an absence of complicating mental disorders and substance-abuse histories, and stronger self esteem and coping skills compared to higher risk patients. The risk increases to moderate when life stress is significant, pain is intractable and social support systems are weak. High-risk patients are marked by major mental health disorders, family and personal histories of substance abuse, histories of sexual and physical abuse (particularly as children), status as smokers, and age less than 50 years.
Patients are monitored according to risk category, with monitoring measures intensifying as the risk rises. See Table 1 (page 14) for a suggested hierarchy of monitoring measures based on risk level. For all patients, clinicians should carefully document the ‘Four As’: analgesia, activities of daily living, adverse events, and aberrant drug taking.6 When abuse risk rises to moderate or high, clinicians should schedule clinic visits more frequently with prescription refills contingent on attendance and, consider as needed, such actions as limiting or eliminating rapid-onset analgesics (ROAs), referring for addiction/psychiatric evaluation, or requiring increased compliance testing via urine or other drug screening.7 When abuse risk is high, many of the most stringent measures, such as referral for treatment of mental health or substance disorders, become mandatory and consideration should be given to appointing a third party, such as a relative, to control and administer medication. In addition, clinicians should limit or eliminate ROAs for the highest-risk patients and also consider limiting short-acting opioids (SAOs). Compliance testing via urine or blood should be intensified, and some screenings should be unanticipated by the patient. When a patient’s risk for abuse appears unclear, it is preferable to monitor that patient more strictly than is necessary for a time than to underestimate the hazards of drug abuse. Monitoring measures can always be adjusted downward once an acceptable level of compliance has been established.
Choosing the Right Opioid Formulation
Patients’ vulnerabilities for opioid abuse are conferred by genetics, environment, and drug properties. The pharmacology of an opioid formulation, though a weaker factor in abuse potential than environmental or genetic influences, is still a significant contributor to abuse risk. Therefore, the drug’s pharmacokinetics, lipophilicity, and attractiveness in terms of abuse potential—particularly to patients with histories of drug abuse—must all be taken into consideration when choosing treatment regimens.