I think it was tramadol that neti mentioned
Common tramadol side effects may include: headache, dizziness, drowsiness, tired feeling; constipation, diarrhea, nausea, vomiting, stomach pain; or feeling nervous or anxious.
If you want to feel nervous take a three yr old to a garden centre....oh lawdy. Turned round to see him waving a ceramic pot above his head, handfuls of gravel have been distributed into plant pots and everything's been patted and examined at far too close quarters (including a customer's dog). The best one was whisking the lid off a rhubarb forcing pot and peering into it for several minutes. He finally looked up and squinted in the sunlight and asked if that was a spider in there....haha. He marched into the shop on his own and had a chat with the assistant about wanting some seeds. I bought him some sunflowers... and nasturtiums because they always grow, not poisonous and they'll attract caterpillars if he's lucky. All round winner :)
Oh, it's his birthday tomorrow (not) and he's been chimbley sweeping with mummy...obviously doctors aren't being paid enough, lol.