[Metabolic Acidosis under Acetaminophen Intake - an Unordinary Side Effect].

Area of Science:

• Nephrology
• Toxicology
• Critical Care Medicine

Background:

• Metabolic acidosis is a frequent complication in hospitalized patients.
• Acetaminophen, a common analgesic, can rarely lead to 5-oxoproline accumulation and metabolic acidosis with high anion gap.

Observation:

• A 73-year-old male with Staph. aureus sepsis developed reduced vigilance and high anion gap metabolic acidosis.
• The patient was on long-term acetaminophen (2g/d) and flucloxacillin therapy.
• Elevated urinary 5-oxoproline concentrations were detected.

Findings:

• Discontinuation of acetaminophen and flucloxacillin, along with acetylcysteine administration, normalized the patient's acid-base balance.
• This case highlights the potential for acetaminophen to induce 5-oxoproline accumulation and metabolic acidosis.

Implications:

• Consider 5-oxoproline accumulation in patients with metabolic acidosis, especially those on acetaminophen, and presenting with sepsis, malnutrition, or liver/kidney disease.
• Prompt interruption of acetaminophen and initiation of acetylcysteine are crucial for managing this specific type of metabolic acidosis.