There's an interesting thing too about metamizol. It's very popular here in Spain for some types of pain (for example, teeth related stuff or post-surgery) and it's used widely without much problem. In fact, it was the most sold medication in Spain in 2023 (sold under the Nolotil brand) [0]. But it's forbidden in places like the UK.
Thing is, as we are a popular destination with British tourists or even pensioners that live in the Mediterranean, we've found in the last years that British population is genetically more likely to have a very dangerous side effect, agranulocytosis, that could result in death.
Can't find the exact source (I'm on my phone), but seems like at least half of the metamizol related agranulocytosis cases in Spain have been of British origin, and several deaths have been reported. There's a ongoing legal process where at least 40 deaths are being investigated [1] and doctor have stopped providing metamizol to persons of British origin, and do it carefully for other persons.
So what was perfectly safe around here, was found quite dangerous for certain subset of the British population (no jokes about balconies, please).
Edit for some sources:
From 1998 to 2003, out of the 13 agranulocytosis cases from a hospital in Marbella, 8 were foreigner, and of those 5 were from the UK [2]. According to the ADAF association, out of the 45 deaths attributed to metamizol in Spain since 1996, only 8 of them were Spanish (they don't tell their sources in that article) [3]
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0: https://fefe.com/wp-content/uploads/2023/05/Obs.-marzo23ok.pdf
1: https://guardian.pressreader.com/article/281857238286709
2: https://www.sciencedirect.com/science/article/abs/pii/S0014256509713104
3: https://www.elespanol.com/ciencia/salud/20231128/denuncian-sanidad-muerte-decenas-britanicos-espana-tomaron-nolotil/812919101_0.html