Ibuprofen × Lithium

Ibuprofen (NSAID) reduces renal prostaglandin synthesis, lowers lithium glomerular clearance, and concurrently increases sodium and lithium reabsorption in the proximal tubules. Serum lithium rises by 20–60% within a week.

Tremor, muscle twitching, nausea, diarrhoea, confusion, ataxia. Severe cases include seizures, coma, and nephrogenic diabetes insipidus with dehydration. Symptoms emerge when serum lithium exceeds 1.2 mmol/L.

Avoid chronic ibuprofen on lithium. For short-term analgesia, use paracetamol, celecoxib, or an opioid. If a short ibuprofen course is needed, reduce lithium by 25–30% and check serum levels at 5–7 days.