The Clinical Opiate Withdrawal Scale (COWS) was developed by Dr. Donald R. Wesson and Dr. Walter Ling in 2003 to assist healthcare professionals in assessing opioid withdrawal severity. It is used across inpatient and outpatient settings to guide treatment decisions, including the initiation of medications like buprenorphine. (Wesson & Ling, J Psychoactive Drugs)

Key Points

  • The Clinical Opiate Withdrawal Scale (COWS) was created by Dr. Donald R. Wesson and Dr. Walter Ling to measure opioid withdrawal severity.
  • COWS scores 11 symptoms including pulse rate, gastrointestinal upset, pupil size, tremors, anxiety, and more.
  • Each symptom is assigned a numeric value, and the total score categorizes withdrawal as mild, moderate, moderately severe, or severe.
  • The scale is used in both inpatient and outpatient detox settings to guide treatment decisions, including the initiation of medications like buprenorphine.
  • Symptom-triggered medication protocols based on COWS scores can improve safety and reduce withdrawal complications.
  • The Subjective Opiate Withdrawal Scale (SOWS) complements COWS by capturing patient-reported symptoms.
  • COWS builds on previous scales like the CIWA-Ar for alcohol withdrawal, providing substance-specific tools for detox management.
  • Accurate withdrawal assessment is critical to preventing relapse and ensuring successful long-term recovery.

The 11 Withdrawal Symptoms on the COWS Scale

COWS evaluates eleven symptoms—similar to a severe flu—plus physiological signs like pulse rate, enabling clinicians to track withdrawal over time.

  1. Resting Pulse Rate: 0 to 4 points (80 bpm or less to over 120 bpm).
  2. Gastrointestinal Upset: 0 to 4 points (none to multiple vomiting/diarrhea).
  3. Sweating: 0 to 4 points (none to sweat streaming off face).
  4. Tremor: 0 to 4 points (no tremor to gross tremor).
  5. Restlessness: 0 to 3 points (able to sit to unable to sit still).
  6. Yawning: 0 to 3 points (none to several times per minute).
  7. Pupil Size: 0 to 3 points (normal to extremely dilated).
  8. Anxiety and Irritability: 0 to 4 points (none to unable to participate).
  9. Bone or Joint Aches: 0 to 3 points (none to visibly sore).
  10. Goosebumps: 0 to 2 points (none to visible piloerection).
  11. Runny Nose & Watery Eyes: 0 to 2 points (none to constant tearing).

A total score classifies withdrawal: 5–12 mild, 13–24 moderate, 25–36 moderately severe, >36 severe.

COWS Scoring Table

COWS Table

 

Symptom Assessment Criteria Scoring
Resting Pulse Rate 80 or below, 81-100, 101-120, greater than 120 bpm 0, 1, 2, 4
Gastrointestinal Upset No symptoms, stomach cramps, nausea or loose stool, vomiting or diarrhea, multiple vomiting/diarrhea 0, 1, 2, 3, 4
Sweating No symptoms, self-reported chills/flushing, observable sweat, sweat on brow/face, streaming sweat 0, 1, 2, 3, 4
Tremor No tremor, felt but not seen, slight observable, gross tremor or muscle twitching 0, 1, 2, 4
Restlessness Able to sit still, difficulty sitting still, frequent shifting, unable to sit still 0, 1, 2, 3
Yawning None, once or twice, three or more times, several times per minute 0, 1, 2, 3
Pupil Size Pinned or normal, larger than normal, moderately dilated, extremely dilated 0, 1, 2, 3
Anxiety and Irritability None, increasing irritability/anxiousness, obvious irritability/anxiousness, difficult participation 0, 1, 2, 4
Bone or Joint Aches None, mild discomfort, severe aches, visibly sore 0, 1, 2, 3
Goosebumps Skin smooth, piloerection felt, piloerection visible 0, 1, 2
Runny Nose and Watering Eyes None, nasal stuffiness/moist eyes, constant runniness/tear streaming 0, 1, 2

Historical Context: COWS & SOWS

The COWS was inspired by earlier alcohol withdrawal scales such as CIWA-Ar and was designed as a practical clinical tool for the rising heroin epidemic in the early 2000s. Its structure parallels that of the Clinical Institute Withdrawal Assessment for Alcohol.

Subjective Opiate Withdrawal Scale (SOWS)

The SOWS, created by Dr. Michael Gossop at the Maudsley Hospital in London, is a patient-reported scale covering broader symptoms such as insomnia and emotional distress. It complements the COWS for a fuller picture of withdrawal. (Gossop, Addict Behav. 1990)

Medically Managed Detox Using COWS

COWS scores guide the appropriate use of medications like buprenorphine or clonidine. A 2018 VA Medical Center study confirmed that symptom-triggered detox using COWS reduced complications and improved retention. (PMC6007729)

Adjunct medications may include:

  • Buprenorphine: Initiated when COWS scores indicate moderate to severe withdrawal.
  • Clonidine: A non-opioid medication that reduces anxiety and sympathetic symptoms.
  • Dicyclomine: Relieves abdominal cramps and spasms.
  • Loperamide: Manages diarrhea symptoms.
  • Zofran (ondansetron): Treats nausea and vomiting.
  • Doxepin or Trazodone: Address insomnia symptoms.
  • Ibuprofen / Acetaminophen: Help relieve general body aches under supervision.

CIWA vs COWS

The CIWA-Ar (Clinical Institute Withdrawal Assessment for Alcohol) is designed to assess alcohol withdrawal symptoms such as hallucinations, tremors, and anxiety. In contrast, the COWS is specific to opioid withdrawal, targeting physiological changes like pupil dilation and elevated pulse rate. Both tools are vital for guiding medication-assisted detox in their respective domains.

References