Medication · Pain & analgesia · full clinical detail
Ibuprofen
A non-steroidal anti-inflammatory (NSAID) that eases pain, inflammation and fever by blocking prostaglandin production; effective but hard on the stomach and kidneys if overused.
Ibuprofen blocks the enzymes that make prostaglandins, the chemical messengers that make injured tissue painful, swollen and hot and that raise your temperature in fever. With fewer prostaglandins there is less pain, swelling and fever. The same messengers protect the stomach and keep blood flowing to the kidneys, which is why ibuprofen can upset the stomach and strain the kidneys.
Route
Oral (tablets, capsules, liquid); topical gel; intravenous in hospital
Uses
Licensed indications
Use
Status
Country · source
Note
Mild to moderate pain including dysmenorrhoea, dental pain, migraine and postoperative pain; fever
Prescription ibuprofen for osteoarthritis and rheumatoid arthritis, mild to moderate pain and dysmenorrhoea; non-prescription for pain, fever and minor aches
NICE: an NSAID, colchicine or a short course of oral corticosteroid for a gout flare, chosen by the person's comorbidities
Licensed indications come from the product licence in the named country; guideline-supported and off-label uses are cited to the guideline that supports them. Licensing differs between countries.
How it works
Ibuprofen blocks the enzymes that make prostaglandins, the chemical messengers that make injured tissue painful, swollen and hot and that raise your temperature in fever. With fewer prostaglandins there is less pain, swelling and fever. The same messengers protect the stomach and keep blood flowing to the kidneys, which is why ibuprofen can upset the stomach and strain the kidneys.
Blocks the cyclo-oxygenase enzymes COX-1 and COX-2, cutting production of prostaglandins, the local messengers that sensitise pain nerves, widen vessels in inflamed tissue and reset the brain's thermostat in fever. The same prostaglandins protect the stomach lining and keep blood flowing through the kidneys, which explains the main harms.
Mechanism of action
Ibuprofen is a propionic acid NSAID that reversibly and non-selectively inhibits COX-1 and COX-2, reducing synthesis of prostaglandins and thromboxane from arachidonic acid. COX-2 inhibition at sites of inflammation reduces PGE2-mediated nociceptor sensitisation, vasodilation and oedema, and central COX inhibition lowers the hypothalamic set-point in fever. COX-1 inhibition in the gastric mucosa reduces protective mucus and bicarbonate and mucosal blood flow (dyspepsia, ulceration, bleeding), in the kidney reduces the prostaglandins that maintain afferent arteriolar dilatation when renal perfusion is threatened (acute kidney injury in dehydration or with ACE inhibitors, ARBs and diuretics), and in platelets transiently impairs aggregation. Ibuprofen occupying platelet COX-1 can also block the access of aspirin to its acetylation site, blunting aspirin's cardioprotective effect when the two are taken together. All NSAIDs carry a dose- and duration-related increase in thrombotic cardiovascular events; ibuprofen at 1200 mg daily or less appears to carry the lowest risk.
Stomach and duodenal ulcers with bleeding or perforation, especially over 65, with steroids, aspirin or anticoagulants
Acute kidney injury, particularly when dehydrated or with ACE inhibitors and diuretics ('triple whammy')
Heart attack and stroke risk rises with high doses and prolonged use, most with diclofenac and COX-2 inhibitors
Worsening asthma in sensitive people; allergic reactions
Source: NHS: Ibuprofen for adults. Frequencies follow the source's categories; no percentages are invented.
Serious safety information
Boxed warning (US). US labelling carries a boxed warning for all NSAIDs: an increased risk of serious cardiovascular thrombotic events (heart attack and stroke), which rises with dose and duration, and of serious gastrointestinal bleeding, ulceration and perforation, which can occur without warning symptoms. NSAIDs are contraindicated for pain around coronary bypass surgery. US
Special warning. Gastrointestinal bleeding and ulceration: UK information advises stopping ibuprofen and seeking urgent help for black stools, vomiting blood or severe stomach pain; risk rises with age, previous ulcers, alcohol and combination with aspirin, anticoagulants, SSRIs or steroids. UK
Special warning. Cardiovascular events: all NSAIDs slightly increase the risk of heart attack and stroke, most at high doses over long periods; ibuprofen at up to 1200 mg a day carries the lowest risk, and people with heart disease or risk factors should use it only when needed. UK
Special warning. Asthma: ibuprofen can provoke bronchospasm in people whose asthma has been worsened by aspirin or NSAIDs before. UK
Warnings and precautions
Kidney. Acute kidney injury can develop when ibuprofen is taken while dehydrated or with ACE inhibitors, ARBs or diuretics; avoid in severe kidney impairment and use the lowest dose for the shortest time in the elderly. UK
Pregnancy. Not recommended in pregnancy unless a doctor advises, and avoided from 20 weeks (US labelling) and particularly from 30 weeks (UK), because NSAIDs can affect the baby's kidneys, the amniotic fluid and the ductus arteriosus. UK
Contraindications
Factor
Detail
Strength
Country · source
Active or previous gastrointestinal bleeding or perforation related to NSAIDs
Contraindicated with a history of gastrointestinal bleeding or perforation caused by an NSAID, or active or recurrent peptic ulceration.
"Absolute" and "relative" follow the wording of the cited source; where the source does not classify, the cell is blank.
Interactions
Check interactions
Taking Ibuprofen with other medicines? Add them to the checker to see what the official sources say about each pair: the mechanism, general management and monitoring, never a bare "safe".
Interactions documented in the official sources cited on each card. The list covers the medicines represented on this site and is not exhaustive; how the interaction data is compiled.
Contraindicated or avoidOfficial guidance: avoid the combination
Ibuprofen and other NSAIDs add to aspirin's stomach irritation and bleeding risk, and ibuprofen taken before low-dose aspirin can block its protective antiplatelet effect.
Contraindicated or avoidOfficial guidance: avoid the combinationtherapeutic duplication
Taking ibuprofen with another NSAID (naproxen, diclofenac, celecoxib, high-dose aspirin) adds stomach, kidney and heart harm without extra pain relief.
Why it can occur
additive bleeding risk
What official information says
UK information advises not taking ibuprofen with similar painkillers such as aspirin or naproxen without talking to a pharmacist or doctor.
What to discuss with a clinician
Official UK information: one NSAID at a time.
Basis of the status
NHS: Taking ibuprofen with other medicines (do not take with similar painkillers)
NSAIDs reduce the kidney's excretion of methotrexate and can raise it to toxic levels.
Why it can occur
renal clearance
What official information says
UK information lists methotrexate among medicines to tell a doctor about; the BNF advises avoiding NSAIDs with high-dose methotrexate and monitoring with low-dose.
What to discuss with a clinician
Official guidance: avoided with high-dose methotrexate; monitored with weekly low-dose methotrexate.
NSAIDs such as ibuprofen can reduce the blood-pressure-lowering effect of losartan and, particularly with a diuretic or dehydration, cause acute kidney injury and high potassium.
Why it can occur
nephrotoxicity · Loss of the renal prostaglandins that keep the afferent arteriole open when angiotensin II is blocked; the 'triple whammy' with a diuretic
What official information says
UK information advises telling a doctor before taking anti-inflammatory painkillers such as ibuprofen with losartan; the BNF advises monitoring renal function.
What to discuss with a clinician
Official UK guidance: avoid regular NSAID use where possible; if used, kidney function and potassium are checked and the person stays well hydrated.
NSAIDs such as ibuprofen can reduce the blood-pressure-lowering effect of lisinopril and, particularly with a diuretic or dehydration, cause acute kidney injury and high potassium.
Why it can occur
nephrotoxicity · Loss of the renal prostaglandins that keep the afferent arteriole open when angiotensin II is blocked; the 'triple whammy' with a diuretic
What official information says
UK information advises telling a doctor before taking anti-inflammatory painkillers such as ibuprofen with lisinopril; the BNF advises monitoring renal function.
What to discuss with a clinician
Official UK guidance: avoid regular NSAID use where possible; if used, kidney function and potassium are checked and the person stays well hydrated.
Any NSAID (ibuprofen, naproxen, diclofenac, celecoxib, high-dose aspirin) with losartan can reduce its effect and cause acute kidney injury and hyperkalaemia.
Why it can occur
nephrotoxicity
What official information says
UK information advises telling a doctor before taking anti-inflammatory painkillers with losartan; the BNF advises monitoring renal function.
What to discuss with a clinician
Avoid regular use where possible; monitor kidney function and potassium if combined.
Therapeutic duplication. Two NSAIDs together (including aspirin at pain-relief doses, or an oral NSAID with a prescription NSAID such as naproxen) add gastrointestinal, kidney and cardiovascular harm without extra pain relief; UK information advises not taking ibuprofen with similar painkillers without advice. UK
Food and drink
With
Effect
Official advice
Food or milk
Taking ibuprofen with or after food reduces stomach irritation, although it slightly slows absorption. (other)
UK information advises taking ibuprofen tablets with a meal or snack, or with milk. UK
Alcohol
Alcohol with ibuprofen increases stomach irritation and the risk of gastrointestinal bleeding. (Additive gastric mucosal injury)
UK information states it is usually safe to drink a small amount of alcohol while taking ibuprofen, but heavy drinking raises the risk of stomach bleeding. UK
Herbal remedies and supplements
With
Effect
Official advice
Ginkgo biloba and other supplements with antiplatelet effects
Possible additive increase in bleeding tendency
UK information notes little research on herbal remedies with ibuprofen and advises telling a pharmacist about any supplement. UK
Monitoring
What
Why
Tests and markers
Source
Kidney function
Before and during longer-term use, particularly in older adults and with ACE inhibitors, ARBs or diuretics
UK information states ibuprofen is not usually recommended in pregnancy unless prescribed, particularly from 30 weeks, because it can cause heart and kidney problems in the baby and reduce amniotic fluid; paracetamol is preferred. UK
Breastfeeding
UK information states ibuprofen is a preferred painkiller while breastfeeding: only tiny amounts pass into milk. UK
Children
Licensed for children from 3 months (over 5 kg) at weight-based doses for pain and fever; not for children with chickenpox because of a possible link with severe skin infection, and used with care in dehydration. UK
Older adults
Older adults are at the highest risk of gastrointestinal bleeding, kidney injury, fluid retention and heart failure from NSAIDs; the lowest dose for the shortest time, usually with a proton pump inhibitor, and often a topical NSAID or paracetamol instead. UK
Kidney impairment
Avoid if possible in kidney disease; contraindicated in severe impairment. Sodium and water retention and a fall in filtration can occur within days, particularly with ACE inhibitors, ARBs and diuretics. UK
Liver impairment
Avoid in severe hepatic impairment (fluid retention, gastrointestinal bleeding, risk of renal failure); use with caution in milder liver disease. UK
Peptic ulcer: contraindicated with active or recurrent ulcers or previous NSAID-related bleeding; a proton pump inhibitor is co-prescribed for others at risk.
Educational summary of drug–condition cautions in the cited sources; not a personal screening.
Effects on tests and results
Creatinine: Creatinine rises and eGFR falls when renal prostaglandins are needed to maintain perfusion; reversible if the drug is stopped promptly. UK
Potassium: Serum potassium can rise, particularly with ACE inhibitors, ARBs or potassium-sparing diuretics. UK
Haemoglobin: Haemoglobin can fall from occult gastrointestinal blood loss. UK
Platelets: Platelet function is reversibly impaired while the drug is present (unlike aspirin's lasting effect). UK
Blood pressure rises by a few mmHg on regular NSAIDs. UK
Pharmacokinetics
Absorption
Rapid and almost complete orally; food delays the peak by about an hour without reducing the total absorbed; topical gel gives high local but low plasma levels
Peak
1-2 hours
Half-life
About 2 hours; dosed every 6-8 hours (modified-release once or twice daily)
Metabolism
Liver, mainly CYP2C9 (and CYP2C8), to inactive hydroxylated and carboxylated metabolites; highly protein bound
Elimination
Metabolites in urine within 24 hours; less than 1% unchanged
Dosing is intentionally not described: doses depend on the indication, the country's licence, kidney and liver function, age, weight and other medicines, and are set by a prescriber.
Medicines that share the class of Ibuprofen. They are separate medicines with their own licences, doses and interactions, not alternative names for Ibuprofen.
Medicines often discussed alongside Ibuprofen: used together, compared with it, or acting on the same problem by a different route.
Educational content. Anatomy Nexus provides medical education and does not replace professional medical advice, diagnosis, treatment, prescribing or pharmacist review. Doses, choices and monitoring are decided by a prescriber for an individual; never start, stop or change a medicine on the basis of this page.
