• N02AA Natural opium alkaloids 74 drugs
• N02AB Phenylpiperidine derivatives 32 drugs
• N02AE Oripavine derivatives 14 drugs
• N02AF Morphinan derivatives 1 drugs
• N02AJ Opioids in combination with non-opioid analgesics 25 drugs
• N02AX Other opioids 64 drugs