Been on Cosentyx for 7 months with no side effects apart from an uptick in bowel activity during loading (which was honestly a welcome relief from the constipation battle - TMI). It did knock me out on injection day at first, I'm on 300mg, but all in all, it's been the best biologic I've had and I hope it keeps working for a long time.
I'd stick with it if your side effects have started to subside, but definitely listen to your own body.
HLA-B27 neg, MTX, Folic Acid, Belbuca, Cosentyx (failed Enbrel, Remicade, Humira). Diclofenac caused kidney failure, Hard breakup with Norco.