Major
Established
الوصف
Naproxen, like all NSAIDs, reduces renal prostaglandin synthesis, impairing lithium excretion and causing lithium toxicity.
الآلية
Naproxen inhibits COX-1 and COX-2, reducing prostaglandin E2-mediated vasodilation of renal afferent arterioles, decreasing GFR and lithium clearance with 25–50% elevation in serum lithium.
الأهمية السريرية
Even short courses of naproxen can precipitate lithium toxicity; the interaction is well-documented across all NSAIDs.
التدبير
Avoid NSAIDs; use acetaminophen for analgesia in patients on lithium; if NSAID is essential, monitor lithium levels within days.