**4. Diagnosis and treatment of opioid use disorder or other SUD in the setting of co-occurring chronic pain**

### **4.1 Approach to the patient**

Patients presenting for care who are suffering from chronic pain and/or SUD must be evaluated with thoroughness, compassion, empathy, and respect. A successful clinical approach typically involves reflective listening, acknowledgment and validation of the patient's feelings, absence of judgment, evident expertise, and use of gentle persuasion for the patient to choose to pursue collaborative and volitional change. Motivational interviewing is one evidence-based technique in which patients are encouraged to consider change without confrontation or power struggle, where the provider will "roll with resistance" expressed by the patient, and instead focus on the patient's strengths while projecting optimism regarding their ability to change with proper support [39, 40].

As noted in the previous section, screening tools can be useful in identifying SUD or potential prescription drug misuse, investigating potential mental health comorbidities, and providing a periodic ongoing reassessment of the plan of care. These ideally can be reviewed along with other relevant patient data either before or during the first consultation visit. A thorough patient history is essential for accurate diagnosis and development of a safe and appropriate treatment plan [41, 42]. Ideally, the practitioner will obtain a good understanding of the patient's subjective symptoms and they are established underlying or co-occurring diagnoses, and a detailed understanding of past and current treatment, including medication management, nonpharmacologic interventions, and self-care practices. As above, the clinical approach to gather history should be non-judgmental and empathetic.

The physical exam is a compulsory, standard-of-care component of a medical evaluation for any new patient, and patients presenting with chronic pain and/or SUD histories are no exception. Naturally, a problem-focused exam of the area(s) of the body where pain symptoms are localized will contribute to the diagnosis, and assessment of symptom severity and functional limitations. For patients with concern for SUD, examination of the skin for evidence of injection sites, both old and more recent, can be illuminating, though, in the era of illicit fentanyl, drug smoking has replaced intravenous use in some locales. Evidence of advanced liver disease may manifest as icteric sclerae, jaundiced skin, or abdominal ascites. Poor dentition can be

## *Management of Co-Occurring SUD and Chronic Pain DOI: http://dx.doi.org/10.5772/intechopen.105721*

a marker of a variety of SUD-related factors but is particularly common with regular use of methamphetamine. The presence of lymphadenopathy in a patient with SUD may be indicative of an immunocompromised state due to HIV, tuberculosis, or other infectious diseases. A thorough neurologic and mental status examination is also critical to establish neurocognitive and behavioral status, motor and/or sensory deficits, and cranial nerve functioning.

Laboratory tests can be helpful in assessing the presence and severity of organ diseases such as liver and kidney functioning, along with evaluation of relevant metabolic, infectious, hemodynamic, hormonal, and other data. Urine toxicology screening is a standard method of evaluating adherence to expectations around the use of prescribed medications and confirming absence of use of unauthorized substances. Imaging tests are often useful in working up musculoskeletal, gastrointestinal, or CNS complaints. Other useful data can typically be found in the electronic health record, such as other practitioners' assessments, as well as easy access to review of the state prescription monitoring program database, which provides evidence for use of prescribed medications and any detection of unreported use of other controlled prescription medications.

## **4.2 Reaching a diagnosis and formulating a treatment plan**

Substance use disorders are diagnosed using the standardized definition provided in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), which contains 11 criteria [26]. Diagnosis is classified as mild with a score of 2–3, moderate with a score of 4–5, and severe with a score of 6 or more. It is important to clarify whether the patient's substance use has the potential to have reached a state of physiologic dependence and/or withdrawal with repeated use and attempted cessation, so that management of withdrawal can be prioritized in the earliest stages of treatment.

There is no single treatment or approach that is appropriate for all patients in all scenarios. Treatment planning should always involve a "menu of options" that is considered in a collaborative fashion in consultation with the patient. Ideally, treatment choices will be informed and supported by other stakeholders such as the patient's loved ones and other members of their care team.

For patients with chronic pain who may have developed OUD, treatment options include the following:


Regardless of the specifics of the treatment approach, all patients who have been identified as misusing prescribed medications or otherwise engaging in unhealthy substance use are deserving of the medical provider's concern and attention. The clinical circumstances should be viewed as a therapeutic opportunity to intervene in an impactful and potentially life-saving way.
