I had a medication which I had to apply for permission to take. It was given. In the list are some every day pain killers.

https://government.ae/en/information-and-services/health-and-fitness/drugs-and-controlled-medicines
The related links at the bottom contains the list of controlled or banned medication.
Unfortunately when you use Google the first link is from a traveller who speaks of the list as mythical and just says to have your prescription, and not to take more than you need.

Citalopram is also a controlled drug in most countries, including the UK, that is only available on prescription. It just highlights that before carrying any drugs across international borders that you need to check what you are and aren't allowed to bring in with you whether for persoanl use or not. For example, you can buy painkillers including codeine in the ingredients over the counter in UK pharmacies but codeine is banned in many countries, including I understand Dubai, and you can expect to encounter difficulties in taking it in to them.

It is always essential to check what is and isn't allowed and what conditions might or might not apply even if the medication is legal in the country you are visiting - what is legal in one country is not not necessarily legal in another country. For example, the restrictions on entering Cuba are very few but one of them is that any medication must be in its original packaging and you must only bring in what would be regarded as sufficient for your planned stay and not an excessive amount. So what I do is keep my regular medication in the blister packs and take any excess out of the boxes and I have had no trouble. But should I ever do what my Mum routinely does when travelling or going on holiday ie taking them out of the blister packs and sorting them out into daily pillboxes for the duration and just taking them with her, I could expect to encounter difficulties at Cuban customs.

He has been released now just read it in the news apparently it wasn't what he took but the fact he took 6 months worth as he was planning a long trip.

My brother-in-law used to live in Oman and his parents went out a few times to visit him. Codeine is banned in Oman but my mother-in-law always insisted on taking Cocodamol with her. What made matters worse was that I think it had been prescribed to her mum rather than to her. I was always told I was being paranoid when I warned about potential difficulties.