* Apremilast (Otezla) is a phosphodiesterase-4 inhibitor that has been approved for use in the treatment of active psoriatic arthritis. Apremilast increases intracellular cyclic adenosine monophosphate, decreasing the levels of several proinflammatory mediators. The most common adverse effects are diarrhea, headache, and nausea. Apremilast may induce or exacerbate depression; serious depression is possible, although not common. Apremilast can also produce significant weight loss.