Increased risk of GI bleeding w/ warfarin, SSRIs. Increased risk of GI bleeding or ulceration w/ steroids, corticosteroids, anti-inflammatory agents. Increased plasma conc of digoxin. Decreased effect of uricosuric agents & α-interferon. Interaction w/ sulphonylureas, probenecid, methotrexate, cyclosporin, tacrolimus, valproic acid, insulin, phenytoin, triiodothyronine, barbiturates & lithium, diuretics. Do not administer simultaneously w/ live flu virus vaccines. Possible case of Reye's syndrome w/ varicella virus vaccine.