Apremilast (Otezla) is a drug you take by mouth that's approved to treat psoriatic arthritis and plaque psoriasis in adults. It's an inhibitor of phosphodiesterase-4 (PDE-4), an enzyme that controls inflammation in a cell.
Side effects include diarrhea, nausea, and headache. Some people in studies who took the drug had weight loss. If you use the medicine, it's recommended that you check your weight regularly and also watch out for signs of depression.