16

Substance Use Disorders

Abdel R. Mohammad DDS, MS, MPH

I. Background

Substance use disorders (SUDs) are characterized by potential for addiction. In 2011, the American Society of Addiction Medicine (ASAM) defined addiction as follows:

Addiction is a primary, chronic disease of brain reward, motivation, memory and related circuitry. Dysfunction in these circuits leads to characteristic biological, psychological, social and spiritual manifestations. This is reflected in an individual pathologically pursuing reward and/or relief by substance use and other behaviors.
Addiction is characterized by:

• Inability to consistently abstain
• Impairment in behavioral control
• Craving
• Diminished recognition of significant problems with one’s behaviors and interpersonal relationships
• A dysfunctional emotional response

Like other chronic diseases, addiction often involves cycles of relapse and remission. Without treatment or engagement in recovery activities, addiction is progressive and can result in disability or premature death.¹

Description of Disease

Alcohol Abuse and Alcoholism

American Medical Association (AMA) and the World Health Organization (WHO) view alcoholism as a discrete disease. In 1992, a panel of members from ASAM and the National Council on Alcoholism and Drug Dependence (NCADD) defined alcoholism as follows:

Alcoholism is a primary chronic disease with genetic, psychosocial, and environmental factors influencing its development and manifestation. The disease is often progressive and fatal. It is characterized by impaired control over drinking, preoccupation with the drug (alcohol), use of alcohol despite adverse consequences, and distortions in thinking, most notably denial. Each of these symptoms may be continuous or periodic.²

Opioid Abuse and Dependence

Opiate drugs, derived from the opium “poppy” are central nervous system (CNS) depressants or “downers” and include morphine, heroin, meperidine, hydromorphone, methadone, and codeine. The number of emergency department visits and hospital admissions related to opiate/narcotic abuse has been increasing. This trend is in contrast to other substances of abuse, such as cocaine and marijuana that are CNS stimulants or “uppers.”

Methamphetamine Abuse

Methamphetamine abuse has been identified as an increasing problem in the United States and has surpassed both cocaine and marijuana as the greatest drug threat in most states. It is a CNS stimulant drug, similar in structure to amphetamine, that is taken orally, intranasally (snorting the powder), by needle injection, or by smoking. Methamphetamine increases the release and blocks the reuptake of the brain chemical (or neurotransmitter) dopamine creating an intense euphoria.

Tobacco Dependence

Tobacco dependence is a chronic medical condition that often requires repeated intervention and multiple attempts to stop. All tobacco forms contain tobacco toxins and carcinogens. Ciga­rettes consist of ground processed tobacco rolled in a flame retardant paper; a filter is usually added.

The morbidity and mortality from chronic cigarette smoking is closely related to:

• total years of smoking,
• number of cigarettes per day,
• depth of inhalation,
• use of filtered versus nonfiltered cigarettes,
• use of mentholated cigarette brands.

Smokeless tobacco (ST) is consumed orally, and the principal types of ST consumed in the United States are chewing tobacco (cut tobacco leaves) and snuff (moist ground tobacco), held between the gum and cheek.

Pathogenesis/Etiology

Alcohol Abuse and Alcoholism

Alcohol dehydrogenase (ADH) serves to break down ingested alcohol that is toxic. Genes for slower metabolizing forms of ADH and alcohol consumption during adolescence both increase the risk of adult alcoholism. Alcohol interacts extensively with the dopaminergic reward neurocircuitry and corticolimbic structures in the developing adolescent brain and alcohol-mediated cognitive dysfunction promotes maladaptive behaviors that lead to addiction.³

Recommendations of the National Institute on Alcohol Abuse and Alcoholism (NIAAA) regarding safe (moderate use) amounts of alcohol consumption include:

• up to two drinks per day for men;
• one drink per day for women and the elderly.
  • (one drink equals one 12-oz bottle of beer or wine cooler, one 5-oz glass of wine, or 1.5 oz of 80-proof distilled spirits).

Moderate use of alcohol in this fashion causes few if any problems and can have distinct health benefits including lowered risks for some forms of cardiovascular disease and cerebrovascular accident, and possibly even a mild protective effect against certain forms of dementia.

People who should not drink at all include:

• women who are pregnant or trying to become pregnant (ingestion during pregnancy can cause fetal alcohol syndrome);
• people who plan to drive or engage in other activities that require alertness and skill (such as operating heavy machinery);
• people taking certain over-the-counter (OTC) medications and prescription medications;
• people with medical conditions that can be exacerbated by drinking;
• recovering alcoholics;
• those <21 years old.

Opioid Abuse and Dependence

Some opiate abusers began their use with prescribed opiates to control pain, while others began their experience from social contacts. Opiate drugs compete with endogenously manufactured opiates at various receptor sites in the brain by attaching to opiate receptors on T lymphocytes and leukocytes.

Methamphetamine Abuse

Methamphetamines are widely used psychostimulant drugs that act on monoamine transporters. They have medicinal properties that are or may be useful in treating a variety of medical conditions but may also be abused. Alterations of intracellular messenger pathways, transcription factors, and immediate early genes within the brain reward system are essential to the development of methamphetamine addiction, with genetic risk factors and changes in gene expression less well understood. The abuse of methamphetamine has been related to neurotoxicity in human long-term abusers, increased risk of stroke, and Parkinson’s disease.⁴

Tobacco Dependence

Tobacco products, whether pyrolytic or non­pyrolytic (see Table 16.1), should be consid­ered contaminated nicotine delivery devices. Nicotine dependence is a SUD. Inhalation is not necessary for nicotine to be absorbed into the bloodstream. The pharmacological objective of any tobacco form is the delivery of nicotine to the user’s brain. Tobacco initiation and progression to nicotine addiction is influenced by sociocultural, psychological, physiological, and genetic factors. Chronic tobacco use is characterized by psychological (habituation, behavioral) and pharmacological (addiction, chemical dependency) factors.

Table 16.1. Tobacco Products Consumed in the United States

A major barrier for most smokers who try to quit is the neurobiology of tobacco dependence, which is fed by the most efficient delivery device of nicotine that exists, the cigarette. Cigarette smoking delivers high concentrations of nicotine to the CNS within seconds of the first puff. The primary target for nicotine in the CNS is the cx4/32 nicotinic acetylcholine receptor. When this receptor is activated by nicotine binding, it results in the release of dopamine in the brain’s reward center and provides the positive reinforcement observed with cigarette smoking.

Epidemiology

Alcohol Abuse and Alcoholism

The prevalence of risky use is 30%; problem drinking varies; harmful use/alcohol abuse 5%; and alcohol dependence/alcoholism 4%. Alcohol use accounts for 85,000 deaths per year and more than $185 billion of health-care spending in the United States.⁵

Opioid Abuse and Dependence

It is estimated that 5–23% of prescription opioid doses dispensed are used nonmedically (without a prescription for the high they cause), through sharing or diverting pills to help a friend or family member with symptoms of physical distress or pain. These unintended users are unlikely to receive information about individualized dosing, possible contraindications, drug interactions, side effects, allergies, or other warnings.⁶

Hydrocodone is the most commonly abused prescription narcotic. Although sometimes viewed as a “white collar” addiction, hydro­codone abuse has increased among all ethnic, age, and socioeconomic groups. Of particular concern is the prevalence of illicit use of hydrocodone among school-age children. In 2010, 4.8% (12 million) of the U.S. population age 12 and older reported using prescription painkillers nonmedically.⁷

Heroin is an abused illegal opiate drug synthesized from morphine and is associated with serious health conditions, including fatal overdose, spontaneous abortion, collapsed veins, pulmonary complications, and in users who inject the drug, infectious diseases.⁸

Methamphetamine Abuse

The 2008 U.S. National Survey on Drug Use and Health: National Findings report stated that the number of past month methamphetamine users aged ≥12 years decreased significantly to 314,000 in 2008.⁹ Recent decreases are believed to have resulted from the U.S. government’s Combat Methamphetamine Epidemic Act of 2005, which limited the amount of the precursor drugs––pseudoephedrine and ephedrine––that could be sold OTC and required secure storage of these drugs in pharmacies.

Tobacco Dependence

In 2010, an estimated 19.3% (45.3 million) of U.S. adults were current cigarette smokers, 78.2% smoke daily. Smoking prevalence is higher among men (21.8%) than women (17.3%).¹⁰

Tobacco use is responsible for approximately one death every 1.5 minutes (443,000 tobacco-related deaths annually). The average smoker begins at age 13 and becomes a daily smoker by age 14. Approximately 20% of all dental patients are tobacco users. Another 20% of all dental patients are young people who should be encouraged not to begin use of tobacco products.

In 2010, approximately 8.1 million (3.2%) of U.S. adults 12 years of age or older were current (within the past month) ST users, 13.3 million Americans (5.4% of the U.S. population aged 12 years or older) smoked cigars, and 2.0 million (0.8% of that same population) smoked pipes. Studies show that over 80% of tobacco users want to stop; however, because of the addictive properties of nicotine in tobacco products, many need professional intervention.

Coordination of Care between Dentist and Physician

Dentists have the responsibility to ask relevant questions about a patient’s medical history and the opportunity to look for subtle clues that may lead to a diagnosis of substance abuse, and eventually to life-changing treatment. They should be vigilant in identifying the patient with active disease, so as to provide the appropriate referral to physicians and substance use support personnel.

Dental team members can assist patients and physicians by:

• screening for alcohol/drug/tobacco use and abuse;
• providing alcohol/drug/tobacco prevention information;
• providing brief interventions––directing patients with abuse problems to health-care providers for assessment and treatment;
• supporting dependent patients during their recovery and minimizing relapse in recovering patients.

The patient’s primary care physician should be consulted initially when an alcohol, drug, or SUD is known or suspected. Some patients—those who have received professional treatment for SUDs—may have an ongoing relationship with an addictionist (i.e., a physician with ad­vanced education and certification in treating addictive disorders). Given the breadth of potential medical problems associated with SUDs, including the prevalence of infectious diseases in the drug-using population, the physician can provide information of great value to the dentist.

In these medically complex patients, the dentist should review the accuracy of patient-provided information about current medications and overall health status. These patients may be poor medical historians because they do not understand what they have been told about their health status or because they deny the severity of it. The physician may be able to provide critical historical information. The physician should also be able to provide critical information to the dentist about hepatic status, clotting times, experience with pain management, the potential for unpredictable metabolism of medications, and drugs to be avoided. This is the appropriate time to discuss the use of sedatives, oral anxiolytics, anesthetics, and postoperative pain medication as well as relapse prevention strategies. Physicians may have very specific requests or contracts with their recovering patients (particularly those with a history of abusing prescription medications).

This may include that the patient ask each provider to consult with their physician, that the physician be aware of every prescription received from any provider, and that essential prescriptions be written or dispensed in such a way as to minimize abuse potential (i.e., several small prescriptions rather than one larger amount, or that the patient’s sponsor dispense the medication).

II. Medical Management

Screening, Brief Intervention, Referral, and Treatment (SBIRT)¹¹

SBIRT is a comprehensive, integrated, public health approach to the delivery of early intervention and treatment services for persons with SUDs, as well as those who are at risk of developing these disorders:

• Screening quickly assesses the severity of substance use and identifies the appropriate level of treatment.
• Brief intervention focuses on increasing insight and awareness regarding SUDs and motivation toward behavioral change.
• Referral to treatment provides those identified as needing more extensive treatment with access to specialty care.

A key aspect of SBIRT is the integration and coordination of screening and treatment components into a system of services. This system links a community’s specialized treatment programs with a network of early intervention and referral activities that are conducted in medical and social service settings.

Identification

Alcohol, Opioid, and Methamphetamine Abuse

Primary care physicians should screen by history for substance use at every health maintenance exam or initial pregnancy visit. Several validated screening tools include Alcohol Use Disorders Identification Test (AUDIT), fast alcohol screening tool (FAST), TWEAK (for pregnant women), Michigan Alcohol Screen­ing Test (MAST, MAST-Geriatric [MAST-G]), Paddington Alcohol Test (PAT), rapid alcohol problem screen (RAPS-4), CAGE Survey, and Substance Abuse Subtle Screening Inventory (SASSI).¹²

Health professionals should maintain a high index of suspicion for substance use in persons with:

• a family or personal history of an SUD;
• recent stressful life events and lack of a social support mechanism;
• chronic pain or illness (including a pattern of drug seeking), trauma, mental illness;
• at-risk substance use, which is defined as any illicit drugs; >3 drinks/day or >7 drinks/week in women; >4 drinks/day or >14 drinks/week in men; or >1 drink/day if age >65.
• physical and cognitive disabilities including alcohol use before age 15 and a medical condition associated with substance use.

Tobacco Dependence

Every health-care provider, including the dental team, should identify the smoking patient, advise him or her to quit, assess readiness to make an attempt, assist with the quit attempt (setting a quit date, motivational literature, pharmacotherapy), and arrange for follow-up. Even without full assist and arrange actions, using a practical “assisted referral” approach for assessing tobacco use, providing tailored advice and brief counseling, and encouraging smokers to talk by telephone with a specially trained tobacco counselor, the health team can contribute to increased abstinence rates and patient satisfaction among smoking patients.¹³

Medical History

Alcohol, Opioid, and Methamphetamine Abuse

A diagnosis of either substance dependence or abuse is made when symptoms indicate a maladaptive pattern of substance use resulting in clinically significant impairment or distress. Patients may directly report use or recovery status on the health history or manifest signs that raise suspicion of undiagnosed and untreated dependence.

Tobacco Dependence

There are several forms in which tobacco can be used: cigarettes (traditional, herbal omni), cigars, pipes, smokeless, and lozenges. Smoking can result in systemic and upper aerodigestive tract diseases and increase the risk of several forms of cancer including lung cancer, heart disease, and a number of nonmalignant oral conditions and diseases.

Physical Examination and Laboratory Testing

Alcohol, Opioid, and Methamphetamine Abuse

Although the medical consequences of alcohol abuse are visible in almost every organ system of the body, to a large extent, the same is true for other drugs of abuse. A pathological condition in any organ system may affect the patient’s oral health and subsequent dental treatment.

Analysis of body fluids, hair, or breath can document the presence or absence of a substance (or its metabolites) in the body, but it does not reveal anything about the cardinal symptoms of compulsion, loss of control, tolerance, or withdrawal. Medical test results such as liver function test patterns and altered platelet counts can be strongly indicative of alcoholism, but often do not appear until late-stage illness. The absence of abnormal test results does not indicate the absence of addictive illness. Currently, there is no definitive laboratory procedure for diagnosing alcohol dependence or identifying a genetic susceptibility for this or any of the other addictive illnesses.

Tobacco Dependence

Signs of chronic tobacco use:

• tobacco smell on clothes, hair, and skin;
• premature wrinkling of the skin and yellowing of the fingers and nails;
• presence of tobacco-related cancers and other diseases such as osteoporosis, emphysema, chronic obstructive pulmonary disease, and cardiovascular diseases;
• reduced taste and smell acuity that may result in dietary changes including increased dietary use of salt, sugar, and spices.

Biomarkers of tobacco control:

• Cotinine, the major metabolite of nicotine, has a half-life of 18–20 hours and can be used to quantify an individual’s exposure to nicotine.
• Anabasine, present in trace amounts in tobacco smoke, may help distinguish abstinent tobacco users who are using nicotine replacement therapy (NRT) from those who are continuing to use tobacco.

Medical Treatment

Alcohol, Opioid, and Methamphetamine Abuse

A variety of approaches may be useful for the management of patients with SUDs involving integrated psychiatric, pharmacological, and psychosocial treatments.

Pharmacotherapy for Alcoholism¹⁴

Three oral medications are currently approved to treat alcohol dependence:

• Disulfiram (Antabuse®) discourages drinking by making the person taking it feel sick after drinking alcohol.
• Naltrexone (Depade®, ReVia®) acts in the brain to reduce the craving for alcohol after someone has stopped drinking.
• Acamprosate (Campral®) works by reducing symptoms that follow lengthy abstinence, such as anxiety and insomnia.

In addition, an injectable, long-acting form of naltrexone (Vivitrol®) is available.

Other types of drugs are available to help manage the symptoms of withdrawal (such as tremor, nausea, and diaphoresis) that may occur after someone with alcohol dependence stops drinking.

Pharmacotherapy for Opiate Abuse and Dependence¹⁵

Several treatment options are available for patients dependent on opiates:

• Methadone—Methadone is similar to morphine and is used in addiction detoxification and opioid maintenance therapy (OMT) programs to reduce the withdrawal symptoms for patients addicted to heroin or narcotics. (Methadone can also be prescribed in a physician’s office, but only if it is being used to treat pain.)
• Buprenorphine sublingual tablets (Suboxone® and Subutex®)—Buprenorphine is a Schedule II narcotic but is a partial agonist with a long half-life, features that reduce its abuse potential. Subuxone also contains the narcotic antagonist naloxone, which is not absorbed when taken sublingually but discourages diversion for intravenous abuse. Buprenorphine can be used for both OMT and detoxification. In detoxification, it can be tapered comfortably on a symptom-based schedule.
• Naloxone (Narcan®)—An opioid antagonist used for the complete or partial reversal of opioid depression.

Tobacco Dependence

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