| Physical and chemical barriers |
Resists chewing, crushing, cutting, grating, grinding, pulverizing; dissolving produces a viscous substance that cannot be drawn into a syringe |
| Agonist‐antagonist combination |
Opioid with a corresponding antagonist (to reduce or defeat euphoria associated with abuse; antagonist released only through tampering) |
| Aversive agent |
Opioid is combined with an aversive agent released during tampering (eg, nasal irritant) |
| Delivery system |
Method of drug delivery offers resistance to abuse (eg, sustained‐release depot injectable, subcutaneous implant) |
| Prodrug |
Opioid is released after the parent drug is ingested and metabolized (usually requires stomach enzyme); opioid is not activated through alternative route of administration |
