Nanna58, I have been on the max dose of Sulfazalazine for many years.
Initially, I suffered dreadful nausea and indegestion. It was so debillitating, I was absolutely miserable.
With the approval of my consultant, my GP prescribed anti nausea tablets to help cope with it.
Also, if you take Omneprazole at least one hour before your first dose, that may help. You cannot take them at the same time, as the Omneprazole inhibits the Sulfasalazine.
I persevered, because I can't tolerate most of the RA drugs , ended up in Coronary Care with a reaction to one RA drug and was running out of options.
Please speak to your GP or consultant, it will eventually settle down and in my case, persevering paid off.
I hope you feel better soon.