No matter what step he takes next, he should check with the person who wrote the prescription. The description is too general to act on. The other medication may produce fewer unwanted effects for him or it may not. Reducing the amount or simply remaining at the present level without further increases can sometimes allow adjustment. Standard schedule for this medication is usually gradual.
Here's some background before I ask what to do. My father has been working on dropping weight for some time. He managed to lose some but the doctors still viewed him as overweight so they started him on semaglutide. He's taken it for roughly a month and a half and is now at 1 mg. Every time I see him he says it leaves him feeling awful. It upsets me to watch him go through this and I don't know what to recommend. Should the amount be reduced? Should he pause and resume later? I don't know much about the medication so any thoughts would help.