Drug interactions in the treatment of rheumatoid arthritis and psoriatic arthritis

Background Treating patients with inflammatory joint diseases (rheumatoid arthritis, psoriatic arthritis) according to established treatment algorithms often requires the simultaneous use of three or more medications to relieve symptoms and prevent long-term joint damage as well as disability. Objective To assess and give an overview on drug-drug interactions in the pharmacotherapy of inflammatory joint diseases with regards to their clinical relevance. Methods All possible drug combinations were evaluated using three commercially available drug interaction programs. In those cases where only limited/no data were found, a comprehensive hand search of Pubmed was carried out. Finally, the drug-drug interactions of all possible combinations were classified according to evidence-based medicine and a specifically generated relevance-based system. Results All three interaction software programs showed consistent results. All detected interactions were combined in clearly structured tables. Conclusion A concise overview on drug-drug interactions is given. Especially in more sophisticated cases extensive knowledge of drug interactions supports optimisation of therapy and results in improved patient safety.