I checked the side effects expecting something sever and... not really all that unusual. Surprisingly, a lot of drugs have side effects like that, they're just incredibly rare and statistically extremely unlikely (lottery level in some cases). My understanding is everything, even things that are probably unrelated specifically to the drug, is written down in testing. But to be used commonly on the market, those severe symptoms actually have to be rare. It's like chemo. We'd all know it was a dangerous drug if it was actually dangerous, and it certainly wouldn't be "widely used" if it was dangerous as for something like diabetes, another drug would be the more common go-to.