This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
If you or someone near you has taken opioids and is hard to wake, breathing slowly or not at all, call 911 and give naloxone if you have it.
Measuring opioid withdrawal
When someone who is physically dependent on opioids stops or cuts down, withdrawal begins within hours for short-acting drugs such as heroin and fentanyl, or after a day or more for methadone. It is rarely life-threatening in itself but very unpleasant: anxiety, aches, sweating, runny nose, gooseflesh, cramps and diarrhea. The Clinical Opiate Withdrawal Scale (COWS), published by Wesson and Ling in 2003, turns these signs into a number so that withdrawal can be followed over time and treatment timed well.
The 11 items
The clinician observes the patient for a few minutes and rates:
- resting pulse (0 to 4)
- sweating (0 to 4)
- restlessness (0 to 5)
- pupil size (0 to 5)
- bone or joint aches (0 to 4)
- runny nose or tearing (0 to 4)
- stomach upset (0 to 5)
- tremor (0 to 4)
- yawning (0 to 4)
- anxiety or irritability (0 to 4)
- gooseflesh skin (0 to 5)
Only signs that are new and due to withdrawal count; a cold, a fever or anxiety from another cause should not be scored.
Interpretation
| Score | Withdrawal |
|---|---|
| below 5 | none significant |
| 5 to 12 | mild |
| 13 to 24 | moderate |
| 25 to 36 | moderately severe |
| above 36 | severe |
Timing buprenorphine
Buprenorphine binds opioid receptors very tightly but activates them only partly. If it is taken while a full opioid is still attached, it pushes that drug off the receptor and causes sudden, severe precipitated withdrawal. Most protocols therefore wait until the COWS reaches about 8 to 12 or more, typically 12 to 24 hours after the last short-acting opioid and longer after methadone. With fentanyl, which is stored in fat tissue, some clinicians use a low-dose start instead.
Worked example
A patient last used heroin 14 hours ago. Their pulse is 92 (1 point), they report chills (1), find it hard to sit still (1), have slightly large pupils (1), mild aches (1), a stuffy nose (1), stomach cramps (1), a tremor that can be felt (1), yawn twice (1) and feel irritable (1), with smooth skin (0). The COWS is 10: mild withdrawal. Many clinicians would wait an hour or two and reassess before the first buprenorphine dose.
Getting help
Medication for opioid use disorder, buprenorphine or methadone, halves the risk of death. The SAMHSA National Helpline (1-800-662-4357) can point to treatment nearby, and naloxone is available without a prescription at most US pharmacies.