A 32-year-old male with a 5-year history of heroin use presents to the de-addiction clinic. He reports using 2–3 grams of heroin daily and wants to initiate treatment. Which investigation is most appropriate to establish the baseline severity of opioid dependence and guide pharmacotherapy?

Explanation

## Clinical Assessment of Opioid Dependence Severity **Key Point:** The Clinical Opiate Withdrawal Scale (COWS) is the gold-standard validated instrument to quantify the severity of opioid withdrawal and guide the intensity and timing of pharmacotherapy initiation. ### Why COWS is the Investigation of Choice The COWS score: - Measures 11 objective and subjective withdrawal symptoms - Generates a numerical score (5–80) that correlates with withdrawal severity - Guides dosing decisions for methadone or buprenorphine - Helps time induction to prevent precipitated withdrawal - Is reproducible and clinically validated across populations ### Severity Interpretation | COWS Score | Withdrawal Severity | Clinical Action | |---|---|---| | 5–12 | Minimal | Supportive care; consider outpatient induction | | 13–24 | Mild–Moderate | Pharmacotherapy; close monitoring | | 25–36 | Moderately severe | Inpatient management recommended | | >36 | Severe | Urgent pharmacotherapy; inpatient setting | **Clinical Pearl:** COWS is administered at baseline and repeated every 1–2 hours during induction to titrate opioid-agonist dosing safely and avoid both under-treatment (relapse risk) and over-treatment (respiratory depression). **High-Yield:** COWS is the **only validated scale** that directly informs pharmacotherapy dosing in opioid use disorder — it bridges clinical assessment and treatment initiation.