Residency · Residency · Family Medicine
Substance Use Disorders: Screening and Office-Based Treatment
Introduction
Substance use disorders (SUDs) are chronic, relapsing medical conditions that affect approximately 17% of the adult population. Family medicine physicians are uniquely positioned to identify SUDs early through universal screening, provide brief interventions, and deliver office-based treatment including medications for opioid and alcohol use disorders.
Epidemiology
Alcohol use disorder affects approximately 29 million adults in the United States. Opioid use disorder affects approximately 5.6 million adults, with over 80,000 opioid-related overdose deaths annually. Cannabis use disorder is the most common illicit drug use disorder. Tobacco and nicotine use disorder remains the leading preventable cause of death. SUDs frequently co-occur with depression, anxiety, PTSD, and chronic pain.
Screening
Universal Screening Tools
SBIRT (Screening, Brief Intervention, and Referral to Treatment) is the recommended framework for primary care. The AUDIT-C is a three-item alcohol screen, with a score of 4 or more in men and 3 or more in women suggesting unhealthy alcohol use. The full AUDIT is a ten-item version providing severity grading. The DAST-10 is a ten-item drug abuse screening test. The NIDA Quick Screen is a single-question screen for drug use in the past year. The TAPS Tool is a combined tobacco, alcohol, prescription medication, and substance use screener.
When to Screen
Screening should occur at annual wellness visits and new patient encounters, during pregnancy (all trimesters), and when clinical indicators suggest possible SUD, such as missed appointments, unexplained injuries, mood instability, or chronic pain with escalating opioid requirements.
Brief Intervention
Brief intervention uses motivational interviewing techniques including open-ended questions, affirmations, reflective listening, and summaries (OARS). Clear medical advice about risks should be provided in a nonjudgmental manner. Readiness to change is assessed using the stages of change model. For hazardous drinking without dependence, brief interventions reduce consumption by 10 to 30%.
Office-Based Treatment: Alcohol Use Disorder
Pharmacotherapy
| Medication | Dose | Mechanism | Key Considerations |
|---|---|---|---|
| Naltrexone (oral) | 50 mg daily | Opioid antagonist; reduces cravings | Contraindicated with opioid use or acute hepatitis |
| Naltrexone (injectable) | 380 mg IM monthly | Same as oral | Better adherence; requires opioid-free period |
| Acamprosate | 666 mg TID | Glutamate modulation | Safe in liver disease; renally dosed |
| Disulfiram | 250 mg daily | Aversive reaction with alcohol | Requires high motivation and adherence |
| Gabapentin (off-label) | 900-1800 mg/day | GABA modulation | Helpful with comorbid anxiety/insomnia |
| Topiramate (off-label) | 200-300 mg/day | Multiple mechanisms | Weight loss as side benefit |
Naltrexone (oral 50 mg daily or injectable 380 mg monthly) reduces heavy drinking days and cravings and is contraindicated in patients on opioids or with acute hepatitis. Acamprosate (666 mg three times daily) supports abstinence by modulating glutamate, is safe in hepatic impairment, and is renally dosed. Disulfiram (250 mg daily) causes an aversive reaction with alcohol and requires high patient motivation and adherence. Gabapentin (off-label) has emerging evidence for reducing heavy drinking, particularly in patients with comorbid anxiety or insomnia. Topiramate (off-label) reduces heavy drinking days, with weight loss as a beneficial side effect.
Monitoring
Drinking patterns should be tracked with timeline follow-back or brief questionnaires. Liver function tests (AST, ALT, GGT) serve as biomarkers of change. Phosphatidylethanol (PEth) is a sensitive and specific biomarker for recent alcohol consumption.
Office-Based Treatment: Opioid Use Disorder
Medications for Opioid Use Disorder (MOUD)
Buprenorphine-naloxone (Suboxone) is first-line for office-based treatment. As of 2023, the X-waiver requirement has been eliminated, allowing any DEA-licensed prescriber to prescribe buprenorphine. Induction begins when the patient is in moderate withdrawal, with a COWS score of 8 to 12 or greater. The typical maintenance dose is 12 to 16 mg sublingual daily. Micro-dosing using the Bernese method allows initiation without requiring full withdrawal. Naltrexone (extended-release injectable) is given as a monthly injection and requires 7 to 10 days opioid-free before initiation. Methadone is highly effective but restricted to federally certified opioid treatment programs.
Harm Reduction
Naloxone (Narcan) should be prescribed to all patients with OUD and their household members, along with education on overdose recognition and naloxone administration. Safe injection practices should be discussed and referral to syringe service programs offered where available. Fentanyl test strips help detect fentanyl in the drug supply.
Office-Based Treatment: Tobacco Use Disorder
Combination nicotine replacement therapy (patch plus short-acting gum or lozenge) is more effective than single-agent NRT. Varenicline is the most effective single agent and is safe in cardiovascular disease, with the FDA black box warning having been removed. Bupropion SR is useful in patients with comorbid depression but should be avoided in seizure disorders. Pharmacotherapy combined with behavioral counseling produces the best outcomes. The 5 A's framework (Ask, Advise, Assess, Assist, Arrange follow-up) guides the clinical encounter.
Special Considerations
Pregnancy
For tobacco, NRT is first-line along with behavioral counseling. For opioids, buprenorphine (monoproduct) or methadone is the standard of care; opioids should not be withdrawn abruptly as cessation risks fetal distress. There is no safe level of alcohol in pregnancy, and screening should occur at every prenatal visit.
Adolescents
The CRAFFT screening tool is validated for ages 12 to 21. Motivational interviewing and family-based interventions are first-line. Pharmacotherapy data are limited, and referral to addiction medicine is appropriate for complex cases.
Addressing Stigma
Person-first language should be used: "person with opioid use disorder" rather than "addict" or "drug abuser." SUDs should be framed as chronic medical conditions analogous to diabetes or hypertension. Urine drug screening should not be used as a punitive measure but rather as a clinical monitoring tool.
Clinical Pearls
Universal screening normalizes the conversation and increases detection rates; single-question screens are sufficient to start. Buprenorphine is one of the most effective treatments in all of medicine, reducing opioid overdose mortality by approximately 50%. Naltrexone for alcohol use disorder is vastly underprescribed and should be considered for any patient with moderate to severe AUD. Naloxone should be co-prescribed for every patient with OUD or high-risk opioid prescriptions. Brief interventions for hazardous alcohol use are among the most cost-effective preventive services in primary care.
References
- Substance Abuse and Mental Health Services Administration. Key Substance Use and Mental Health Indicators. 2023 National Survey on Drug Use and Health.
- Kampman K, Jarvis M. American Society of Addiction Medicine (ASAM) national practice guideline for the treatment of opioid use disorder: 2020 focused update. J Addict Med. 2020;14(2S):1-91.
- Jonas DE, Amick HR, Feltner C, et al. Pharmacotherapy for adults with alcohol use disorders in outpatient settings: a systematic review and meta-analysis. JAMA. 2014;311(18):1889-1900.
- US Preventive Services Task Force. Screening and behavioral counseling interventions to reduce unhealthy alcohol use. JAMA. 2018;320(18):1899-1909.