Ibuprofen gehört zu den meistverkauften Schmerzmitteln weltweit und ist in Deutschland rezeptfrei erhältlich. Es lindert Schmerzen, senkt Fieber und hemmt Entzündungen. Doch obwohl es frei verkäuflich ist, ist Ibuprofen kein harmloses Medikament: Falsche Dosierung, zu lange Einnahme oder bestimmte Vorerkrankungen können ernsthafte Nebenwirkungen verursachen.
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This article is for informational purposes and does not replace medical advice. For severe stomach pain, blood in stools, difficulty breathing, or chest pain: call 999 or go to A&E immediately.
Ibuprofen is the best-selling over-the-counter painkiller in the UK. It combines three properties in one: pain relief, fever reduction, and — at sufficiently high doses — anti-inflammatory action. This makes it the most versatile OTC painkiller — but also the one with the broadest interaction profile.
| Property | Details |
|---|---|
| Active substance | Ibuprofen (2-(4-isobutylphenyl)propionic acid) |
| ATC code | M01AE01 (propionic acid derivatives) |
| Drug class | Non-steroidal anti-inflammatory drug (NSAID) |
| Available forms | Tablets, capsules, syrup, suppositories, gel/cream, granules |
| Half-life | approx. 2–3 hours |
| OTC up to | 400 mg single dose / 1,200 mg daily dose |
| Prescription required above | >400 mg single dose (e.g. 600 mg, 800 mg) |
| Onset of action | approx. 30–60 min (faster with ibuprofen lysinate) |
Typical indications: back pain, headaches, joint pain, period pain, toothache, and fever.
Ibuprofen inhibits the enzymes cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). These enzymes produce prostaglandins — messenger substances that trigger and amplify pain, fever, and inflammation. Inhibiting both enzymes reduces prostaglandin production, relieving pain, fever, and inflammation.
COX-2 is mainly active at sites of inflammation and is the actually intended target. COX-1, by contrast, has a protective function: it produces prostaglandins that protect the stomach lining and forms thromboxane A2 in the platelets. When COX-1 is inhibited, the stomach lining loses its protection — which explains the stomach problems. And thromboxane levels fall, affecting blood clotting.
Diclofenac is considerably more COX-2-selective than ibuprofen — it inhibits COX-2 more strongly relative to COX-1. COX-2 in the blood vessels produces prostacyclin, which dilates vessels and inhibits clot formation. Strong COX-2 inhibition shifts the balance towards thromboxane — vasoconstriction and thrombosis tendency. With ibuprofen, this effect is smaller than with diclofenac, but present — especially at higher doses above 1,200 mg daily. Above this threshold, ibuprofen's risk of heart attack also rises measurably.
Ibuprofen lysinate is ibuprofen combined with the amino acid lysine. This salt dissolves in water considerably faster than conventional ibuprofen — and is therefore absorbed more quickly by the small intestine. Onset of action is approximately 15–20 minutes earlier. Important: potency and duration of action are identical — ibuprofen lysinate is not stronger, only faster. For acute attacks such as migraine or sudden severe headaches, it is therefore the better choice. It is also somewhat easier on the stomach when taken on an empty stomach than conventional ibuprofen.
The principle is: as low as possible, for as short a time as necessary. This is not a hollow phrase — every additional day and every additional 200 mg increases the gastric, renal, and cardiac risk. NICE guidelines recommend NSAIDs at the lowest effective dose for the shortest possible time.
| Use | Single dose | Max. daily dose | Note |
|---|---|---|---|
| Mild to moderate pain (OTC) | 200–400 mg | 1,200 mg | Max. 3–4 days without seeing a doctor |
| Fever | 200–400 mg | 1,200 mg | Fever lasting >3 days: see a doctor |
| Severe pain (prescription) | 400–800 mg | 2,400 mg | Only with a prescription |
| Rheumatic conditions | 1,200–2,400 mg | 2,400 mg | Long-term use under medical supervision |
Ibuprofen should ideally not be taken on an empty stomach. Taking it during or directly after a meal significantly reduces the risk of stomach pain and heartburn — even if this delays the onset of action by 15–30 minutes. For most everyday situations this is not a problem. Anyone who needs fast action — for example during acute migraine — can use ibuprofen lysinate, which is also better tolerated on an empty stomach.
Further intake rules: take with a large glass of water, not with milk or juice. Swallow tablets whole. Maintain a gap of at least 6–8 hours between individual doses. If a dose has been missed: never double up — simply continue at the next regular time. No alcohol during the course — the combination substantially increases the risk of gastrointestinal bleeding.
Ibuprofen is well tolerated with short, low-dose use. Side effect rates rise substantially with dose and duration, however. The three most relevant risk areas are the gastrointestinal tract, the cardiovascular system, and the kidneys.
Stomach pain, heartburn, and nausea are the most common complaints. They arise because ibuprofen reduces the stomach lining's protective prostaglandins via COX-1 inhibition. With longer use, gastric ulcers and gastrointestinal bleeding can develop — particularly in patients over 65, those taking corticosteroids concurrently, or those with pre-existing stomach conditions. Anyone in these risk groups should only take ibuprofen together with a proton pump inhibitor such as pantoprazole.
Black or bloody stools are a warning sign of gastrointestinal bleeding and always constitute an emergency — call 999 or go to A&E immediately.
At daily doses above 1,200 mg and with long-term therapy, the risk of heart attack and stroke rises measurably. The risk is lower than with diclofenac, but present. Particularly relevant for patients with pre-existing heart disease, high blood pressure, or diabetes. Ibuprofen can also raise blood pressure and reduce the effectiveness of antihypertensives such as ramipril or candesartan. Anyone who notices suddenly worse blood pressure control should think of their painkiller.
Ibuprofen inhibits prostaglandins in the kidneys that are important for regulating the kidney's blood vessels. With short-term use this is not a problem for healthy kidneys. With longer use, dehydration, pre-existing kidney disease, or in combination with diuretics and ACE inhibitors/sartans, the Triple Whammy risk arises: triple burden on the kidneys that can in the worst case lead to acute kidney failure. More on this in chapter 6.
Ibuprofen has a considerable interaction potential that is frequently underestimated in everyday life — because it is available over the counter and therefore considered "harmless". The most dangerous combinations concern cardiac and blood pressure patients.
Anyone taking daily low-dose aspirin for heart protection who additionally takes ibuprofen risks cancelling aspirin's heart-protective effect. The mechanism is the same as with diclofenac: ibuprofen reversibly occupies the COX-1 binding site — before aspirin can bind there irreversibly. If ibuprofen is there first, aspirin finds no free site. The solution: take aspirin at least 30 minutes before ibuprofen — or better, choose paracetamol (acetaminophen) as the painkiller, which does not have this interaction.
The most dangerous three-way combination in self-medication: ibuprofen (or diclofenac) together with an ACE inhibitor such as ramipril or a sartan such as candesartan, and a diuretic gives the Triple Whammy. All three mechanisms strike kidney function simultaneously and can lead to acute kidney failure. Anyone taking antihypertensives and a diuretic should generally avoid ibuprofen and switch to paracetamol. brite's interaction check detects this combination automatically.
| Medication / substance | Interaction | Recommendation |
|---|---|---|
| Low-dose aspirin (heart protection) | Blocks aspirin's antiplatelet effect | Take ibuprofen at least 30 min after aspirin, or use paracetamol |
| Anticoagulants (warfarin, apixaban / Eliquis, rivaroxaban / Xarelto) | Increased bleeding risk | Avoid combination where possible |
| ACE inhibitors / sartans | Effect reduced + Triple Whammy with diuretic | Monitor blood pressure; prefer paracetamol |
| Diuretics | Triple Whammy → kidney failure | Monitor kidney values; drink adequate fluids |
| Lithium | Raises lithium levels → toxicity | Monitor lithium levels |
| Methotrexate | Delays methotrexate excretion → toxicity | Only under medical supervision |
| Corticosteroids | Substantially increased gastrointestinal bleeding risk | Stomach protection (pantoprazole) required |
| SSRIs (citalopram, escitalopram) | 12-fold increased GI bleeding risk | Paracetamol instead of NSAIDs! |
| Alcohol | Increased gastrointestinal bleeding risk | No alcohol during the course |
