This chapter on assessment and treatment of substance use disorders provides guidance, particularly for practitioners interested in pain medicine, on how various forms of substance use disorders are diagnosed and managed clinically. Because detection and management of opioid use disorder poses a major concern for physicians using opioids to treat patients, and because diagnosis of opioid use disorder in this context is often confounded by pain issues, the chapter focuses special attention on this complex clinical conundrum. More specifically, the chapter focuses on patients with chronic nonmalignant pain (CNMP) because issues related to opioid use disorder are more vexing in these patients than in patients with cancer or other lifethreatening illnesses.
Various surveys indicate that individuals with chronic pain disorders are more likely to have substance use disorders than are individuals in the general population,1,2
and individuals with substance use disorders also have high rates of pain disorders.3
Therefore, practitioners treating pain disorders are likely to encounter patients with substance use disorders and will need to know how to screen for and recognize these disorders, diagnose these disorders, make appropriate referrals for and/or treat these disorders, monitor for these disorders during ongoing pain treatment, and manage therapy for chronic pain in the context of these disorders.
The first section of the chapter presents the assessment and treatment of all major forms of substance use disorders from the perspective of addiction medicine. The second section focuses on assessment and treatment of opioid use disorder from the perspective of the pain specialist.
Assessment and Treatment of Substance Use Disorders—Addiction Medicine Perspective
The panoply of substance-related disorders includes intoxication, withdrawal, substance use disorder (otherwise known as addiction), and substance induced psychiatric disorders (e.g., psychosis, mood disturbance, or anxiety caused directly by the use of the substance). Substance use disorders occur with a variety of commonly used substances such as alcohol, cannabis, cocaine, opioids, sedative/hypnotics, stimulants like amphetamines and methylphenidate, inhalants, psychedelic agents, and tobacco. A standardized set of criteria characterizing these disorders is provided in the Diagnostic and Statistical Manual of Mental Disorders
(5th ed., DSM-5
Intoxication and withdrawal obviously differ by substance and can generally be diagnosed through history and physical examination. The criteria for substance use disorder which will be covered in greater detail in the following text are identical across substances.
What is currently termed a substance use disorder
was known as either substance abuse
in prior versions of the DSM
, with abuse being considered a milder form of the disorder. The use of the term dependence
generated some confusion and controversy. In contrast to a commonly held conception of “dependence” as notating purely physiologic changes that occur in response to repeated exposure to a substance, in prior versions of the DSM
, “dependence” referred to a syndrome of physiologic signs and symptoms combined with an array of behavioral disturbances. Prior to the advent of DSM-5
, some suggested that the phrase “substance dependence” referring to the Diagnostic and Statistical Manual of Mental Disorders
(4th ed., text rev., DSM-IV-TR
) syndrome be replaced with the term addiction
to avoid confusion between purely physiologic dependence and the syndrome of substance dependence.5
Others felt that the term addiction
has negative connotations leading to stigmatization. A compromise was settled on with DSM-5
using the term substance use disorder
. It is commonly understood that the terms addiction
and substance use disorder
are essentially synonymous and interchangeable.
SCREENING AND RECOGNITION
Clearly, some initial evidence must arise through screening to suggest that a patient has a substance use disorder to trigger a thorough diagnostic assessment. In many cases, screening and diagnostic evaluation may overlap. The idea of “universal precautions” in pain medicine has been advanced as one way to detect potential substance use problems in all pain patients, so there may be some value in routine use of some or all of these screening procedures.6
However, it is often too time-consuming and cumbersome to perform them in primary care, and there is no strong evidence that universal precautions or routine screening leads to better outcomes.
Generally, a thorough history of substance use obtained through a matter-of-fact, nonjudgmental interviewing style will provide a great deal of information or even a formal diagnosis. Most patients are not aware of guidelines for safe quantities of alcohol consumption and will readily divulge the amount of their drinking. Many patients are more reluctant to discuss use of illicit substances, but some will freely admit to such use if they do not fear sanctions or punishment. Oftentimes, this openness is more likely to occur during initial intake. Patients may be less forthright during the course of treatment if they believe they have something to lose by admitting to use. If time allows, it is worth asking explicitly about frequency and quantity of use for each class of substance along with route of administration. It is also quite important to ask about any history of current and past problematic substance use, as such problematic use is known to increase the risk of recurrence in the context of pain management. It is useful to know what types of substance use disorders treatment, if any, have been helpful for the patient in the past.
Recommended safe quantities of alcohol use consist of no more than four standard drinks per day (or more than 14 total per week) for men and three standard drinks (or more than 7 total per week) for women.7
The recommended quantities are less for women because women tend to have less total body water and thus a lower volume of distribution for alcohol.8
Quantities of different forms of alcohol that define a standard drink are listed in Table 91.1
. If patients acknowledge regularly consuming more than the recommended amounts or describe heavy drinking such as five or more drinks on one occasion for men or four or more for women, a more thorough diagnostic evaluation for alcohol use disorder should be pursued.
TABLE 91.1 Quantities of Alcohol that Define a Standard Drink (14 g Pure Alcohol)
Quantity in Standard Drink (in Fluid Ounces)
Spirits (gin, vodka, whiskey)
For illicit substances, any suggestion of more than occasional recreational use of marijuana should prompt a more thorough diagnostic evaluation. It is also important to look for tobacco use disorder, as this disorder has been associated with increased risk of opioid misuse in a number of studies.1,9
Routine blood work can provide an indication of excessive alcohol use. Suggestive findings include elevations in liver transaminases or macrocytic, hyperchromic red blood cells related to alcohol’s interference with folate absorption, and subsequent folate deficiency. Positive serologies for past or current hepatitis B or C infection or HIV infection would raise concerns about a substance use-related mode of transmission.
In addition, specific laboratory testing to detect presence of substances in body fluids offers a convenient component of screening. Typically, urine is tested,10
although tests can also be readily performed in oral fluid or blood.11,12
Substances that have been used are likely to remain present in urine for a longer period than they will in other body fluids (Table 91.2
). For urine testing, a screening test is typically performed via immunoassay. When needed, confirmatory tests using high-performance liquid chromatography/mass spectrometry or gas chromatography/mass spectrometry can be ordered. It is important to note that the routine urine assay for opioids does not detect oxycodone, methadone, buprenorphine, or fentanyl which each requires a specific screening test. Heroin can only be detected shortly after use if its intermediate metabolite, 6-monoacetylmorphine, is present. Subsequently, 6-monoacetylmorphine is rapidly metabolized to morphine. If morphine appears in a urine toxicology specimen, it could represent either pharmaceutical morphine use or heroin use. It is difficult to detect alcohol in urine, blood, oral fluid, or breath unless the use has been quite recent. However, the alcohol metabolites, ethyl glucuronide or ethyl sulfate, indicating recent alcohol use can be detected in urine, blood, or hair.13
A number of self-report questionnaires have been designed to help in screening for substance use disorders, and these can be utilized prior to, concurrent with, or subsequent to the history, physical, and laboratory evaluation to help determine whether a patient warrants more thorough diagnostic evaluation. Although the instruments described in the following text have definite utility in primary care and general populations as well as selected samples such as psychiatric patients, they have not been tested in pain patients.
TABLE 91.2 Drug Detection Times in Urine and Drug Plasma Half-lives
Detection Time in Urine (Based on Standard Cutoff Values)
Cocaine metabolite (Benzoylecgonine)
Heroin metabolite (6-monoacetylmorphine)
3 d single use
7-9 d maintenance dosing
Cannabis single use
Cannabis chronic use
In screening for alcohol use disorders, the currently most frequently used instruments are the Alcohol Use Disorders Identification Test (AUDIT)14
and the Michigan Alcoholism Screening Test (MAST).15
The AUDIT has 10 items related to quantity and frequency of alcohol consumption and to maladaptive behaviors associated with alcohol use and can be completed in about 5 minutes. Each item is scored 0 to 4. A score of 8 or more for men under age 60 years or 4 or more for women or men over age 60 years are considered positive screens indicative of need for further assessment. A shorter version of the AUDIT, the AUDIT-C, which asks only 3 questions related to consumption has also been validated as a screening instrument in primary care settings.16
The MAST contains 25 questions and focuses more on problem behaviors associated with alcohol use. Each item counts for 1 point, and a score of 6 or more indicates a positive screen with need for further assessment. There are shorter versions of the MAST which also appear to function as adequate screening instruments.
In the context of managing pain patients where urine toxicology should be readily available, self-report instruments to screen for drug use problems are probably less useful than a positive urine toxicology. However, if use of a self-report screening instrument is desired, a commonly used instrument is the Drug Abuse Screening Test (DAST).17
The DAST is based on the MAST and has 28 items concerning both intensity and frequency of drug use and problematic behaviors associated with drug use. As with the MAST, each item counts for 1 point, and a score of 6 or more points to the needs for further assessment. Shorter versions of the DAST also exist.
A much briefer option to screen for a possible drug use disorder is the single item question, “How many times in the past year have you used an illegal drug or used a prescription medication for nonmedical reasons?” This single item performed as well as the DAST-10 at detecting a substance use disorder.18
One recently validated instrument that screens for all major substances is the Tobacco, Alcohol, Prescription Medication, and Other Substance Use (TAPS) tool, which is reasonably brief and can be self-administered.19
PRESCRIPTION DRUG MONITORING PROGRAM
Most states in the United States provide prescription drug monitoring programs (PDMPs). How they function and what the requirements are to access them vary widely from state to state. They do provide information on most controlled substance prescriptions that individual patients have obtained. Checking the PDMP can be very helpful in verifying the prescription medications that the patient is reporting via history.20
As noted earlier, criteria provided in DSM-5 represent the most standard way to make a diagnosis of a substance use disorder. At times, it proves fruitful to interview family members if the patient is not forthcoming.
criteria for opioid use disorder as an example. The criteria for a substance use disorder are identical across all substances. To determine the presence or absence of the diagnosis, the interviewer should focus one by one in turn on each substance of potential relevance and systematically go over each of the criteria with the patient for each substance.
TABLE 91.3 Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Diagnostic Criteria for Opioid Use Disorder
A problematic pattern of opioid use leading to clinically significant impairment or distress, as manifested by at least two of the following occurring within a 12-mo period:
Opioids are often taken in larger amounts or over a longer period than was intended.
There is a persistent desire or unsuccessful efforts to cut down or control opioid use.
A great deal of time is spent in activities necessary to obtain the opioid, use the opioid, or recover from its effects.
Craving, or a strong desire or urge to use opioids
Recurrent opioid use resulting in a failure to fulfill major role obligations at work, school, or home
Continued opioid use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of opioids
Important social, occupational, or recreational activities are given up or reduced because of opioid use.
Recurrent use of opioids in situations in which it is physically hazardous
Continued opioid use despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the substance
Tolerance,a as defined by either of the following:
A need for markedly increased amounts of opioids to achieve intoxication or desired effect
A markedly diminished effect with continued use of the same amount of opioid
Withdrawala as manifested by either of the following:
The characteristic opioid withdrawal syndrome
Opioids (or a closely related substance) are taken to relieve or avoid withdrawal symptoms.
a This criterion is not considered to be met for those taking the substance solely under appropriate medical supervision.
Mild = 2-3 symptoms.
Moderate = 4-5 symptoms.
Severe = 6 or more symptoms.
There are 2 physiologic criteria, tolerance and withdrawal, and 9 behavioral criteria. Two or more of the 11 criteria must be present at any one time over a 12-month period to make the diagnosis. If 2 to 3 criteria are present, the disorder is classified as mild; if 4 to 5 are present, as moderate; and if 6 or more, as severe. The physiologic criteria are not considered to be met for individuals taking the substance under medical supervision. For example, a pain patient treated chronically with opioids who is taking them precisely as prescribed might display tolerance to the effects of opioids and withdrawal signs and symptoms if the medication is stopped, but in this situation, these two criteria would not be applied to the diagnosis of opioid use disorder. Similarly, this scenario could occur with an attention-deficit/hyperactivity disorder patient treated chronically with stimulants, or with an anxiety disorder patient treated chronically with benzodiazepines. Conversely, an individual might not have either tolerance or withdrawal but could have the DSM-5 defined substance use if he or she meets at least two of the behavioral criteria, although this scenario occurs rarely in clinical practice. Inspection of the criteria reveals that questions about each criterion are unlikely to be interpreted by patients as critical or threatening and unlikely to engender resistance or deception, particularly if posed in a matter-of-fact, nonjudgmental fashion. Although this procedure sounds time-consuming, it frequently can be accomplished in a matter of minutes for each substance of concern. As mentioned at the outset, the diagnosis of opioid use disorder in a patient with CNMP being treated with opioids may not be as straightforward as simple application of the DSM-5 criteria and is discussed in detail in the following text.
Diagnosis of a substance use disorder certainly should not preclude appropriate interventions for a pain problem and in rare instances, with appropriate monitoring and safeguards, may not categorically preclude opioid treatment of chronic pain.
Co-occurring Psychiatric Disorders
Mental health disorders frequently co-occur with substance use disorders.21,22
It is likely that chronic pain patients who have substance use disorders will have another non-substancerelated co-occurring mental health disorder.23
Oftentimes, co-occurring mental health and substance use disorders interact with negative synergy so that exacerbation of one disorder in turn exacerbates the other.24
Thus, if a pain patient does have a substance use disorder, it is imperative to evaluate that patient for other co-occurring mental health disorders and provide appropriate clinical intervention (including pharmacotherapy and/or psychotherapy) for any that are diagnosed.
TREATMENT AND/OR REFERRAL
Some general comments about treatment and referral will be made, and then specific interventions for use disorders involving each particular class of substances will be outlined. Most physicians get virtually no training or experience in treatment of substance use disorders and, therefore, often feel helpless or hopeless in the face of these disorders. Although many patients with these disorders who do get treatment get it in specialized settings that operate in parallel to and oftentimes outside of mainstream medicine, many patients will refuse a referral to such settings, and a growing body of literature supports the efficacy of physician intervention as a reasonable first attempt at treating these disorders.
Specialty Substance Use Disorders Treatment
If a referral to a specialized substance use disorders treatment provider is needed, the referral could be made to an individual practitioner, another physician, psychologist, social worker, or chemical dependency counselor who specializes in substance use disorders treatment and could work with the patient in a private office setting using one or more of the psychotherapeutic or behavioral interventions detailed in the following text. Frequently, the referral will be made to an addiction treatment or substance use disorders program or agency. The American Society of Addiction Medicine publishes Patient Placement Criteria that can aid in determining what level of addiction treatment is appropriate for a given patient. These criteria have not, however, been fully scientifically validated and are based largely on expert opinion.29,30
Medically Supervised Withdrawal
Some patients, who manifest withdrawal when stopping their substance use, may need medically supervised withdrawal (also known as detoxification
) to stop the substance safely and engage in treatment. The most common substances which require supervised withdrawal are alcohol, sedative-hypnotics, and opioids, although patients may have very unpleasant withdrawal symptoms from marijuana, cocaine, or amphetamines and need some support and monitoring. Medically supervised withdrawal can be accomplished on an outpatient or inpatient basis depending on the severity of the withdrawal. Clearly, alcohol or sedative-hypnotic withdrawal can be life-threatening. Usually, benzodiazepines are prescribed over several days in tapering doses.31
Supervised opioid withdrawal for physiologic dependence on opioids can be accomplished using methadone in a licensed treatment program32
(see the following text) or with buprenorphine33
by appropriately qualified physicians. Alternatively, the α2
-adrenergic agonist, clonidine, can be prescribed to attenuate opioid withdrawal signs and symptoms and tapered over several days.34
Some paradigms, known as ultrarapid opioid withdrawal
, have been developed whereby opioid withdrawal is precipitated with an opioid antagonist such as naloxone or naltrexone under sedation or general anesthesia to complete the withdrawal in a brief period of time. These rapid procedures have no better outcomes than more gradual withdrawal but do have more adverse events such as pulmonary problems and psychiatric instability so they are not recommended.35
It is very important to understand that medically supervised withdrawal (detoxification) alone does not constitute treatment. If medically supervised withdrawal is not immediately followed by more definitive substance use disorders treatment, relapse is almost universal.