Ibuprofen Toxicology

Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that reduces levels of the hormones that cause pain, inflammation, swelling and fever. It is used to treat conditions such as toothache, headache, arthritis, back pain and menstrual cramps.

Like other NSAIDs, ibuprofen is associated with a number of side effects. Overdosing on the drug can lead to toxicity and serious harmful effects, although the risk of life threatening complications or death is low. The effects of overdose include symptoms that range in severity, from no symptoms at all through to those requiring intensive care. Toxic effects are usually not seen at doses of less than 100 mg/kg but they can be severe when doses exceed 400 mg/kg.

Some of the symptoms of toxicity from ibuprofen are described below.

Gastrointestinal effects

Gastrointestinal blood loss due to ibuprofen intake occurs in a dose-related manner. This blood loss occurs in up to 17% of patients who receive 1,600 mg per day and in almost a quarter of those who receive 2,400 mg per day.

The risk of severe gastrointestinal side effects is increased among those with a previous history of serious gastrointestinal events and those who abuse alcohol. For these patients, ibuprofen should be used with caution.

Mild and transient gastrointestinal side effects are the most frequently reported effects, occurring in up to a quarter of patients and they include nausea, vomiting, dyspepsia, diarrhea, flatulence and abdominal pain. The more serious gastrointestinal effects such as occult blood loss, gastrointestinal hemorrhage, ulcer and pancreatitis, are uncommon.

Effects on the liver

Elevations in liver function tests are found in up to 15% of patients. The hepatic side effects cholestasis, hepatitis, jaundice and hepatic failure have rarely been reported. Ibuprofen has also been implicated in children with acute vanishing bile duct syndrome and in acute hepatitis among patients with chronic hepatitis C. Patients with liver disease require regular liver function tests when they are receiving ibuprofen. Ibuprofen-induced hepatitis can lead to fatality.

Renal effects

Renal side effects include urinary retention, renal insufficiency, acute renal failure, nephrotic syndrome and acute tubular necrosis. Reduced renal function may increase the risk of these side effects.

Cardiovascular effects

Examples of cardiovascular effects include elevated blood pressure, which occurs in less than 1% of patients receiving ibuprofen and peripheral edema, which affects between 1% and 3% of patients. This may be important in patients who already have high blood pressure or congestive heart failure. Ibuprofen may also inhibit antihypertensive effects in patients already receiving medication for high blood pressure.

Nervous system

Side effects that involve the nervous system are rare and include drowsiness, dizziness and headache. Several cases of aseptic meningitis associated with ibuprofen use have also been reported. The incidence of this side effect is more common among patients with systemic lupus erythematosus or other diseases of the connective tissue, although it has also occurred in patients without these underlying conditions.

Hematologic effects

Hematologic side effects include neutropenia, platelet dysfunction, aplastic anemia, agranulocytosis, eosinophilia, thrombocytopenia, hemolytic anemia and decreased hemoglobin and hematocrit.

Although uncommon, a reduced serum hemoglobin may occur in cases of occult gastrointestinal blood loss.

Hypersensitivity effects

Hypersensitivity side effects include pruritis, urticarial rashes, bronchospasm, angioedema, and anaphylactoid reactions and they are particularly likely to occur in individuals who have asthma, nasal polyps or bronchospastic reactivity to aspirin. The occurrence of systemic reactions such as interstitial nephritis and Steven-Johnson syndrome have been reported in rare cases.

Dermatologic effects

Dermatologic effects are rare and include pruritis, vasculitis, alopecia, maculopapular rash, erythema multiforme and vesiculobullous eruptions. Photosensitivity reactions have also been reported.

Ocular effects

Examples of ocular side effects include blurred vision, scotomata and diplopia.

Further Reading

• All Ibuprofen Content
• What is Ibuprofen?
• Ibuprofen Chemistry
• Ibuprofen Mechanism
• Ibuprofen Side Effects

Written by

Sally Robertson

Sally has a Bachelor's Degree in Biomedical Sciences (B.Sc.). She is a specialist in reviewing and summarising the latest findings across all areas of medicine covered in major, high-impact, world-leading international medical journals, international press conferences and bulletins from governmental agencies and regulatory bodies. At News-Medical, Sally generates daily news features, life science articles and interview coverage.