Drug interactions
Lithium + Naproxen
Severity: Major
Lithium and Naproxen: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Naproxen can raise serum lithium concentrations and may lead to lithium toxicity with tremor, confusion, ataxia, vomiting and diarrhea. The risk is greater with renal impairment, dehydration or advanced age.
What this interaction means in plain words
Lithium and Naproxen can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Lithium belongs to Central Nervous System; Naproxen belongs to Musculoskeletal.
Why it happens
NSAID inhibition of renal prostaglandins reduces renal blood flow and lithium clearance, increasing lithium reabsorption.
What to do
Avoid the combination where possible, or measure lithium levels at baseline and within about a week of starting naproxen, reducing the lithium dose as required. Counsel the patient to report signs of toxicity.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Naproxen
- Ketorolac intranasal + Naproxen Contraindicated
- Ketorolac + Naproxen Contraindicated
- Aceclofenac + Naproxen Major
- Acemetacin + Naproxen Major
- Acetylsalicylic acid + Naproxen Major
- Alteplase + Naproxen Major
Other interactions of Lithium
- Lithium + Thioridazine Contraindicated
- Lithium + Vandetanib Contraindicated
- Aceclofenac + Lithium Major
- Acemetacin + Lithium Major
- Amisulpride + Lithium Major
- Amlodipine-benazepril + Lithium Major
Frequently asked questions
Can I take Lithium with Naproxen?
MediHelp rates the interaction as major. Lithium and Naproxen can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Naproxen can raise serum lithium concentrations and may lead to lithium toxicity with tremor, confusion, ataxia, vomiting and diarrhea. The risk is greater with renal impairment, dehydration or advanced age.
How serious is the interaction between Lithium and Naproxen?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible, or measure lithium levels at baseline and within about a week of starting naproxen, reducing the lithium dose as required. Counsel the patient to report signs of toxicity.
What other medicines interact with Naproxen?
MediHelp also lists interactions of Naproxen with, for example, Ketorolac intranasal, Ketorolac, Aceclofenac. The full list is on the Naproxen page.
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