Ibuprofen (Motrin) Overdose: Emergency Evaluation and Treatment
For ibuprofen overdose, immediately assess airway, breathing, and circulation while initiating gastrointestinal decontamination with activated charcoal if the patient presents within 1-2 hours of ingestion, and provide aggressive supportive care targeting metabolic acidosis, hypotension, and CNS depression—the primary life-threatening complications. 1
Immediate Assessment and Risk Stratification
Determine the ingested dose immediately, as toxicity correlates with dose:
- Ingestions <100 mg/kg typically produce minimal to no symptoms 2
- Ingestions >400 mg/kg carry significant risk for severe toxicity including coma, metabolic acidosis, renal failure, and death 3, 4
- All symptomatic patients developed toxicity within 4 hours of ingestion in prospective studies 2
Obtain baseline laboratory studies immediately: serum ibuprofen concentration, complete metabolic panel, arterial blood gas, lactate, and renal function tests 1, 4. Therapeutic ibuprofen levels are 10-50 mcg/mL; levels >100 mcg/mL indicate significant overdose, and levels >200-300 mcg/mL are associated with severe toxicity and potential fatality 1, 3.
Gastrointestinal Decontamination
Administer activated charcoal 1 g/kg (maximum 50 g) orally if the patient presents within 1-2 hours of ingestion and can protect their airway 1, 4. The FDA label specifically notes that "little drug will likely be recovered if more than an hour has elapsed since ingestion," but activated charcoal may still reduce absorption and reabsorption 1.
Do not induce vomiting or perform gastric lavage unless the patient presents within 30-60 minutes of a massive ingestion (>400 mg/kg) and cannot receive activated charcoal 1. These interventions are generally not recommended due to limited efficacy and aspiration risk 4.
Life-Threatening Complications and Management
Metabolic Acidosis
Severe metabolic acidosis is the hallmark of serious ibuprofen toxicity and requires aggressive correction 3, 4, 2. Administer intravenous sodium bicarbonate to maintain arterial pH >7.2 and promote urinary alkalinization, which theoretically enhances ibuprofen excretion since it is an acidic drug 1, 4.
Cardiovascular Collapse
Hypotension and shock occur in massive overdoses (>400 mg/kg) and may be refractory to standard vasopressor therapy 3, 4. Provide aggressive fluid resuscitation with crystalloids initially 4. If hypotension persists despite adequate fluid resuscitation, initiate vasopressor support with norepinephrine or dopamine 3.
Central Nervous System Depression
CNS manifestations range from mild drowsiness to coma 1, 4, 5. Intubate and mechanically ventilate patients with GCS ≤8 or those unable to protect their airway 4. One case report documented reversal of CNS depression with naloxone 0.1 mg/kg IV, though this is not standard therapy and requires further validation 5.
Renal Failure
Acute kidney injury can develop from direct nephrotoxicity and hypoperfusion 2, 6. Monitor urine output closely and maintain adequate intravascular volume 4. Consider renal replacement therapy (hemodialysis or continuous veno-venous hemofiltration) for severe cases with refractory acidosis, electrolyte abnormalities, or oliguric renal failure 3, 6.
Extracorporeal Elimination
Consider hemodialysis or continuous hemofiltration for patients with:
- Serum ibuprofen levels >700-800 mg/L 3, 6
- Refractory metabolic acidosis despite sodium bicarbonate 3, 6
- Cardiovascular collapse unresponsive to vasopressors 3, 6
- Deteriorating clinical status despite maximal supportive care 6
However, recognize that even with aggressive renal replacement therapy, mortality can occur in massive overdoses (>500 mg/kg) 3, 6.
Monitoring and Disposition
Admit all patients with:
- Ingestions >400 mg/kg regardless of symptoms 3, 2
- Any symptomatic patient (GI upset, drowsiness, tachycardia) 4, 2
- Serum ibuprofen level >100 mcg/mL 1, 2
- Metabolic acidosis (pH <7.35 or elevated lactate) 4, 2
Observe asymptomatic patients with ingestions of 100-400 mg/kg for at least 4-6 hours 2. If they remain completely asymptomatic with normal vital signs and laboratory studies at 4-6 hours post-ingestion, they can be medically cleared for psychiatric evaluation or discharge 2.
Discharge patients with ingestions <100 mg/kg who remain asymptomatic after 4 hours of observation 2.
Critical Pitfalls to Avoid
Do not assume ibuprofen overdose is benign based on early presentation—severe toxicity including coma, shock, and death can occur, particularly with sustained-release formulations that may have delayed absorption 6.
Do not delay supportive care while waiting for serum ibuprofen levels—clinical presentation and estimated dose should guide initial management 4.
Do not overlook co-ingestions—always screen for acetaminophen and other substances, as combination toxicity significantly worsens prognosis 3.
Recognize that hypothermia is an ominous sign in massive ibuprofen overdose and indicates severe toxicity with high mortality risk 3.