FAAH and osteoarthritis: FAAH inhibitors have yet to reach the clinic as analgesics,60 with a major clinical trial with the irreversible FAAH inhibitor PF-04457845 failing to induce effective analgesia in patients with pain due to osteoarthritis of the knee.17 Whether this is a compound specific problem and/or whether efficacy would be achieved for another pain disorder remains to be fully determined.