Interactions between herbal remedies and antirheumatic drugs.

Many patients with rheumatological conditions use herbal remedies as an adjunct to their conventional antirheumatic medication, often without seeking advice. Herbal remedies are exempt from the usual drug safety requirements and may be a cause of both adverse effects and drug interactions. Data on interactions between herbal remedies and conventional antirheumatic medication is scarce. Reasons include a perception that herbal remedies are safe, a lack of reporting by patients and healthcare professionals and a lack of knowledge about the pharmacology and composition of herbal remedies, as well as adulteration. Interactions are likely between herbal remedies with antiplatelet or nephrotoxic effects and NSAIDs, hepatotoxic herbal remedies and disease-modifying antirheumatic medication, and between St. John's Wort and cyclosporin.