Fenbufen (Lederfen) is a non-steroidal anti-inflammatory drug used primarily to treat inflammation in osteoarthritis, ankylosing spondylitis, and tendinitis. It can also be used to relieve backaches, sprains, and fractures. Fenbufen is available as a capsule or tablet sold with the brand names Cepal, Cinopal, Cybufen, Lederfen, and Reugast. Fenbufen acts by preventing cyclooxygenase from producing prostaglandins which can cause inflammation.

COX-1:3.9 μM, ATP systhesis:0.88 μM(Ki), Caspase-4:0.57 μM, Caspase-1:4.4 μM, COX-2:8.1 μM, Caspase-3:1.2 μM, Caspase-5:0.87 μM, Caspase-9:0.76 μM

Fenbufen and its metabolites could be involved in mitochondrial toxicity through inhibition of ATP synthesis[1]. Fenbufen inhibited prostaglandin release by 80% and reduced rates of protein synthesis in normal muscle and in muscle undergoing hypertrophy in response to tenotomy of a synergist[3].