Ibuprofen can cause dangerous increases in lithium blood levels, leading to lithium toxicity. Lithium has a very narrow therapeutic range, and even small increases in blood levels can cause serious neurological, kidney, and cardiac toxicity that may be irreversible.
How This Interaction Works (Mechanism)
Ibuprofen reduces renal prostaglandin synthesis, which decreases renal blood flow and glomerular filtration rate. Lithium is almost entirely eliminated by the kidneys, and its reabsorption in the proximal tubule is linked to sodium reabsorption. When renal prostaglandins are inhibited, lithium clearance drops by approximately 20 to 25 percent, causing levels to rise into the toxic range. The effect can occur within a few days of starting ibuprofen.
Source: American Psychiatric Association Lithium Monitoring Guidelines, 2025
Avoid ibuprofen and all NSAIDs while taking lithium unless specifically approved by your psychiatrist. Use acetaminophen for pain relief. If an NSAID is necessary, check lithium levels within 5 to 7 days of starting and monitor closely. Low-dose aspirin (81 mg) has less effect on lithium levels and may be a safer alternative for mild pain. Report any tremor, confusion, vomiting, or unsteadiness immediately.
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Sources and standards behind this page
What a drug interaction does, and how strongly it is supported, is documented in public labeling and federal safety references rather than in any one summary, and the sources below are the primary ones. They are linked so a reader can check a claim without taking this page's word for it.
- DailyMed carries the current FDA labeling for every marketed drug product, including the warnings and drug interaction sections.
- Drugs@FDA is the federal database of approved drug products and their approval documents.
- FDA: Drug interactions, what you should know explains how drug-drug, drug-food and drug-condition interactions are described on labels.
- FDA Drug Safety Communications publishes the agency's safety alerts and label changes as they are issued.
- FDA MedWatch is the program for reporting and reviewing adverse events, including suspected interactions.
- openFDA provides public access to FDA labeling and adverse event data.
- MedlinePlus drug information is the National Library of Medicine's consumer reference for what a medicine is and how it is taken.
- NIAAA: Harmful interactions documents which medicines interact with alcohol and how.
- NCCIH: Herb-drug interactions summarises the evidence on interactions between herbal products and medicines.
- National Library of Medicine maintains the drug and health databases the sources above draw on.
This page describes how this interaction works and where it is documented. It is not medical advice: a prescriber or pharmacist decides what applies to a particular patient and medication.
Frequently Asked Questions
Lithium and Ibuprofen have a severe interaction and should generally not be taken together without close medical supervision. The combination can cause serious, potentially life-threatening side effects. Contact your doctor immediately if you are currently taking both medications.
Ibuprofen can cause dangerous increases in lithium blood levels, leading to lithium toxicity. Lithium has a very narrow therapeutic range, and even small increases in blood levels can cause serious neurological, kidney, and cardiac toxicity that may be irreversible.
Yes. Anytime you are taking multiple medications, supplements, or substances, you should inform your doctor and pharmacist. They can evaluate your specific risk factors (age, kidney function, other medications, medical conditions) and determine whether the Lithium and Ibuprofen combination is safe for you, or whether adjustments are needed.
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