| Ocfentanil |
opioid |
39th ECDD (2017) - Critical review |
| OPIUM (note 3 page 6) |
opioid |
None
|
| Oripavine |
opioid |
33rd ECDD (2003) - Pre-review, 34th ECDD (2006) - Critical review |
| Ortho-fluorofentanyl |
opioid |
41st ECDD (2018) - Critical review |
| OXAZEPAM |
benzodiazepine |
None
|
| OXAZOLAM |
benzodiazepine |
None
|
| Oxpheneridine |
other |
7th ECDD (1957) - Critical review , 12th ECDD (1962) - Critical review |
| OXYCODONE |
opioid |
None
|
| Oxymorphone |
opioid |
9th ECDD (1959) - Critical review |