Opioids & Synthetic Opioids
Comprehensive Substance Reference & Harm Reduction Guide
Opioids & Synthetic Opioids
GUIDE-WIDE SAFETY NOTICE: This guide is for recognition, harm-reduction, and emergency-reference purposes. Appearance alone cannot reliably identify a substance. Counterfeit pills, powders, vapes, edibles, and street mixtures may contain unexpected drugs. Do not taste, smell closely, burn, or handle an unknown substance to identify it. If poisoning is possible, contact Poison Control (U.S. 1-800-222-1222) or 911 for severe symptoms.
1. Opioids & Synthetic Opioids
| Substance | Appearance, Route & Intoxication | Physical Side Effects | Severe Toxicity / Overdose & Response |
| Fentanyl | Fine/chunky white, off-white, beige, or light-brown powder; counterfeit tablets; patches/lozenges. Snorted, smoked, injected, swallowed. Pinpoint pupils, heavy sedation, nodding, slurred speech. | Constipation, nausea/vomiting, itching, dry mouth, dizziness, slowed breathing, reduced bowel motility. | Overdose: Unresponsiveness; very slow/stopped breathing; gurgling/snoring; blue/gray skin/lips; limp body. Response: 911, naloxone, breathing support/CPR, recovery position. Repeat naloxone if needed. |
| Heroin | White, tan, brown powder or dark sticky tar. Snorted, smoked, injected. Pinpoint pupils, nodding, itching, drowsiness. | Constipation, nausea/vomiting, itching/flushing, dry mouth, slowed breathing; injection infections and vein damage. | Overdose: Respiratory depression, unconsciousness, blue/gray skin, choking/gurgling. Response: 911, naloxone, breathing support, recovery position. |
| Oxycodone / Hydrocodone | Prescription tablets/capsules; imprints. Usually swallowed. Drowsiness, pinpoint pupils, slowed speech. | Constipation, nausea/vomiting, itching, dizziness, dry mouth, sweating, slowed breathing. | Overdose: Unresponsiveness, slow/stopped breathing, clammy/blue/gray skin. Response: 911, naloxone, breathing support. |
| Morphine / Methadone | Tablets, oral liquids, injectables. Oral/injected. Sedation, pinpoint pupils, slowed breathing. | Constipation, nausea, sweating, itching, dizziness, sedation; methadone can cause QT prolongation (heart rhythm). | Overdose: Profound sedation, severe respiratory depression, coma. Prolonged effects. Response: 911, naloxone, airway/breathing support; continued monitoring. |
| Buprenorphine / Suboxone | Sublingual films/tablets, injections/implants. Drowsiness, small pupils, slowed reactions. | Constipation, nausea, headache, sweating, dizziness, sleepiness; slowed breathing rises with other sedatives. | Overdose: Marked sedation/respiratory depression with alcohol/benzos/opioids. Response: 911, naloxone, breathing support. |
| Codeine | Prescription tablets/capsules/cough liquids. Oral. Sleepiness, small pupils, nausea. | Constipation, nausea/vomiting, itching, dizziness, sleepiness, slowed breathing. | Overdose: Respiratory depression, unconsciousness, choking. Response: 911, naloxone, breathing support. |
| Tramadol | Prescription tablets/capsules. Oral. Drowsiness, dizziness, nausea, possible agitation. | Nausea, constipation, dizziness, sweating, headache; lowers seizure threshold, contributes to serotonin toxicity. | Overdose: Seizures, respiratory depression, altered consciousness. Response: 911 for seizures/abnormal breathing, naloxone for opioid component, EMS evaluation. |
| Hydromorphone / Oxymorphone | Potent prescription tablets/injectables. Oral or injected. Sedation, pinpoint pupils, slowed breathing. | Constipation, nausea/vomiting, itching, dizziness, profound drowsiness. | Overdose: Rapid respiratory depression, coma, cyanosis. Response: 911, naloxone, airway/breathing support. |
| Nitazenes / Emerging Synthetic Opioids | Powders or counterfeit pills; non-distinctive. Variable routes. Opioid signs: pinpoint pupils, sedation, stopped breathing. | Marked sedation, nausea/vomiting, pinpoint pupils, slowed breathing, low oxygen; highly unpredictable potency. | Overdose: Profound and prolonged respiratory depression. Response: 911, immediate naloxone, breathing support, repeat naloxone as needed. |