Major
Diclofenac × Lithium
Non-steroidal anti-inflammatory drugs (NSAIDs)×Psycholeptics. Lithium
Mechanism
Similar to naproxen + lithium. NSAIDs reduce renal lithium clearance via prostaglandin blockade.
Symptoms
Tremor, muscle twitching, nausea, diarrhoea, confusion, ataxia. Symptoms emerge when serum lithium exceeds 1.2 mmol/L.
Management
Avoid prolonged combination. If diclofenac is needed for a short course, reduce lithium by 25–30% and check level at 5–7 days. For chronic analgesia: paracetamol.
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.