Major
Ibuprofen × Lithium
Non-steroidal anti-inflammatory drugs (NSAIDs)×Psycholeptics. Lithium
Mechanism
Ibuprofen reduces lithium renal clearance by inhibiting prostaglandin synthesis in the proximal tubule. Lithium plasma concentration rises 25–60%, leading to intoxication. Lithium has a narrow therapeutic index (target 0.6–1.0 mmol/L, toxic above 1.5).
Symptoms
Within 5–10 days: nausea, vomiting, diarrhea, tremor, confusion, drowsiness. Severe toxicity: seizures, coma, renal injury, arrhythmia.
Management
In bipolar disorder, paracetamol is the first-line analgesic. If an NSAID is needed, use a short course (up to 5 days); check lithium level 4–7 days after NSAID start and 4–7 days after stop. Reduce lithium by 50% and titrate to level.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.