Bioethical approach to determine the feasibility of using medicines involves systemic analysis of pharmacoepidemiological and pharmacoeconomic aspects of treatment, especially while treating the most common and chronic diseases. Psoriasis is the most common disease of the skin and subcutaneous tissue, accounting for 15% of cases. The rate of psoriatic complications constitutes 6–42%. Skin lesions, psoriatic arthritis, cardiovascular diseases, metabolic syndrome, inflammatory intestinal diseases, mental disorders and malignant lesions produce a great effect on health, duration and quality of life, and result in early loss of labor capacity and disability of patients. So, it is important to study effectiveness and safety of systemic medicines in patients with severe and moderate-to-severe disease and perform subsequent analysis of possible use and comparison of the effectiveness of various combinations. Most affordable but ineffective medicines commonly cause real growth of further expenses on treatment, and postpone administration of more effective, though much more expensive medicines. Economic aspects of rational use of healthcare resources are becoming increasingly important whereas pharmacoeconomic values are crucial while selecting a treatment strategy.