In the UK, ibuprofen, aspirin and paracetamol are sold freely everywhere (but only in small packs). Painkillers containing codeine are available over the counter, after talking to a pharmacist. Anything stronger requires a prescription.
The 500/5 cocodamols will cause liver damage before any codeine kicks in.
What is interesting is that if you really interesting is that a certain large pharmacy does a 200/12 ibuprofen + codeine combo.
I once had a prolapsed lower disc (from sport) and neck spasm (from stupidity) at the same time. Whilst I couldn't take naproxen (lots of reflux even with omeprazole), that and 500/15 cocodes with diazepam was the only way to get to sleep.