Interactions between glucocorticoids and warfarin in chronic inflammatory (autoimmune) diseases

Overview

Glucocorticosteroids are still very important part of the treatment of chronic inflammatory disorders. Their use is often accompanied by unpleasant adverse effects, problems associated with withdrawal during their long-term use and interactions with conco­mitantly administered drugs. One of the important interactions that may often occur in clinical practice is interaction with warfarin. Despite the fact that as glucocorticosteroids so warfarin are used for many years and seem to be completely known, their co-administration is still accompanied by uncertainties. The interaction may have pharmacodynamic or pharmacokinetic character and both types result in increased risk of bleeding. The pharmacodynamic interaction can be expected to increase a risk of gastrointestinal bleeding to which a gastrotoxicity of glucocorticosteroids contributes. A pharmacokinetic interaction is considered to influence a hepatic metabolism of warfarin and to increase its availability. The exact mechanism is still not fully understood. Manifestations of both types of interactions are taken up with a delay. Co-administration requires increased attention and close monitoring of international normalized ratio. At higher doses of glucocorticosteroids proton pump inhibitors are also effective in prevention of gastrotoxicity.

Key words:
glucocorticosteroids – warfarin – interaction – rheumatology – autoimmune disorders