It is very uncertain whether metronidazole changes adverse events compared with budesonide enema (very low certainty).
It is very uncertain whether methotrexate changes adverse events (Ardizzone 2003) compared with 6‐MP or azathioprine (very low certainty).
It is very uncertain whether methotrexate + infliximab changes adverse events (Schröder 2006) compared with infliximab alone (very low certainty).
It is very uncertain whether methotrexate + infliximab changes serious adverse events (Schröder 2006) compared with infliximab alone (very low certainty).
It is very uncertain whether ciprofloxacin changes adverse events compared with metronidazole (very low certainty).
5‐ASA showed no clear difference in adverse events compared with purine antimetabolites (low certainty).
Azathioprine or 6‐mercaptopurine may leads to lower adverse events compared with methotrexate (low certainty).
It is very uncertain whether 6‐Mercaptopurine changes adverse events compared with methotrexate (very low certainty).
Tacrolimus showed no clear difference in total adverse events compared with beclometasone (low certainty).
Tacrolimus showed no clear difference in serious adverse events compared with beclometasone (low certainty).
It is very uncertain whether 5‐ASA changes serious adverse events compared with purine antimetabolites (very low certainty).
It is very uncertain whether 6‐Mercaptopurine changes serious adverse events compared with methotrexate (very low certainty).
5‐ASA may leads to lower withdrawal due to adverse events compared with purine antimetabolites (low certainty).
It is very uncertain whether azathioprine or 6‐mercaptopurine changes withdrawals due to adverse events compared with methotrexate (very low certainty).
It is very uncertain whether 6‐Mercaptopurine changes withdrawals due to adverse events compared with methotrexate (very low certainty).