Drug General Information (ID: DDI3K4SUD7)
Drug Name			Caffeine		Drug Info		Methotrexate		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antihypertensive Agents				Antimetabolites
Structure

Mechanism of Caffeine-Methotrexate Interaction (Severity Level: Moderate)
Attenuated pharmacological effects (Unspecific) Click to Show/Hide Mechanism Graph
Drug Name		Caffeine				Methotrexate
Mechanism		Interfere with the efficacy of methotrexate in patients with rheumatoid arthritis				Methotrexate
Key Mechanism Factor 1
		Factor Name		Pharmacodynamics
		Factor Description		Reduced pharmacological effects leading to insufficient efficacy and/or treatment failure.
Mechanism Description		Attenuated pharmacological effects of  Caffeine when combined with Methotrexate

Recommended Action
Management		Until further information is available, the potential for interaction should be considered in patients who consume substantial amounts of caffeine and caffeine-containing foods and are prescribed methotrexate for rheumatoid arthritis. It may be appropriate to limit caffeine intake if an interaction is suspected in cases of treatment failure.

References
1	Grapefruit juice interactions with drugs. Med Lett Drugs Ther 37 (1995): 73-4. [PMID: 7630329]
2	Nesher G, Mates M, Zevin S "Effect of caffeine consumption on efficacy of methotrexate in rheumatoid arthritis." Arthritis Rheum 48 (2003): 571-572. [PMID: 12571869]