- Concomitant use of drugs which may be susceptible to interactions with diclofenac, or affect safety if used concomitantly (serotonin-selective reuptake inhibitors (SSRI), lithium, digoxin, anticoagulants, antidiabetic agents, cyclosporin, methotrexate, quinolone antimicrobials, other NSAIDs, steroids and diuretics)