DRUG CLASS AND MECHANISM: Arthrotec is a combination of diclofenac and misoprostol. Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) similar to ibuprofen (Motrin or Advil), naproxen (Naprosyn), and others that is used to treat inflammation, pain, and fever. Diclofenac, like other NSAIDs works by inhibiting the production of prostaglandins. Prostaglandins are a family of chemicals produced by the cells of the body that promote inflammation, pain, and fever. In addition, they support the function of platelets that are necessary for the clotting of blood, and protect the lining of the stomach from the damaging effects of acid.