Metabole acidose met verhoogde anion gap ten gevolge van 5-oxoprolinurie bij gelijktijdig gebruik van acetaminofen en flucloxacilline

Abstract

Metabolic acidosis with increased anion gap due to 5-oxoprolinuria with concomitant use of acetaminophen and flucloxacillin 5-oxoprolinuria is a relatively rare metabolic disorder in which there is accumulation of 5-oxoproline leading to a high anion gap metabolic acidosis. The acquired form is usually caused by simultaneous use of acetaminophen (also known as paracetamol) and flucloxacillin, which is not uncommon. The exact incidence and prevalence of the acquired form are not known. This disorder is most likely under-reported as the test used for diagnosis is not always performed nor easy accessible. Diagnosing 5-oxoprolinuria requires testing urine or serum of a patient for the presence of organic acids, which are highly elevated in 5-oxoprolinuria. Due to the relative rareness of the disorder, cases are easily missed. 5-oxoprolinuria should always be suspected in a patient with unexplained high anion gap metabolic acidosis and/or therapy with flucloxacillin with or without the concomitant use of acetaminophen. Treating 5-oxoprolinuria is straightforward and consists of stopping the offending drug(s) which mostly leads to a spontaneous recovery. Treatment with sodium bicarbonate and/or N-acetylcysteine are also described in the literature, but at present there is not sufficient evidence supporting their use.