If your arthritis is more severe, your doctor may prescribe disease-modifying anti-rheumatic drugs (DMARDs). These slow down the progression of the arthritis and its effects and also ease its symptoms. They can take weeks or months to have an effect, so continue taking them even if they seem not to be making any difference. You may need to try a few to find a DMARD that suits you. If you have severe psoriatic arthritis and other medicines haven't worked, you may be prescribed 'biologic' medicines made from animal or human proteins that block the progress of psoriatic arthritis in your immune system. However, they aren't suitable for everyone.
Attribution: BUPA