Search

Purpose A patient was identified with severe metabolic acidosis, a high anion gap and 5-oxoproline accumulation, probably caused by the simultaneous use of paracetamol (acetaminophen) and flucloxacillin. We wanted to investigate the necessity to control the interaction between both drugs with an automatic alert system. Methods To investigate the relevance of the interaction of paracetamol and flucloxacillin, a retrospective study was conducted. Data on paracetamol and flucloxacillin prescriptions and laboratory data (pH, Na+, HCO3 −, Cl−, albumin and 5-oxoproline levels) were combined to assess the prevalence of acidosis, calculate the anion gap and analyse 5-oxoproline levels in clinically admitted patients using both drugs simultaneously. Results In the 2-year study period, approximately 53,000 admissions took place in our hospital. One thousand and fifty-seven patients used paracetamol and flucloxacillin simultaneously, of which 51 patients (4.8%) had a serum pH ≤ 7.35. One patient, the same patient as presented in the case report, had a high anion gap and a toxic level of 5-oxoproline. Conclusion The prevalence of metabolic acidosis is very low and the only patient identified with the interaction was recognised during normal clinical care. We conclude that automatic alerts based on simultaneous use of paracetamol and flucloxacillin will generate too many signals. To recognise patients earlier and prevent severe outcomes, a warning system (clinical rule) based on paracetamol, flucloxacillin and pH measurement may be helpful. Early calculation of the anion gap can narrow the differential diagnosis of patients with metabolic acidosis and measurement of 5-oxoproline can explain acidosis due the interaction of paracetamol and flucloxacillin. Electronic supplementary material The online version of this article (doi:10.1007/s00228-017-2311-6) contains supplementary material, which is available to authorized users.

Background: The effect of angiotensin II receptor blockers on right ventricular (RV) function is still unknown. Angiotensin II receptor blockers are beneficial in patients with acquired left ventricular dysfunction, and recent findings have suggested a favorable effect in symptomatic patients with systemic RV dysfunction. The current study aimed to determine the effect of losartan, an angiotensin II receptor blocker, on subpulmonary RV dysfunction in adults after repaired tetralogy of Fallot. Methods: The REDEFINE trial (Right Ventricular Dysfunction in Tetralogy of Fallot: Inhibition of the Renin-Angiotensin-Aldosterone System) is an investigator-initiated, multicenter, prospective, 1:1 randomized, double-blind, placebo-controlled study. Adults with repaired tetralogy of Fallot and RV dysfunction (RV ejection fraction [EF] Results: Of 95 included patients, 47 patients received 150 mg losartan daily (age, 38.0±12.4 years; 74% male), and 48 patients received placebo (age, 40.6±11.4 years; 63% male). Overall, RV EF did not change in patients allocated to losartan (n=42) (44.4±5.1% to 45.2±5.0%) and placebo (n=46) (43.2±6.3% to 43.6±6.9%). Losartan did not significantly improve RV EF in comparison with placebo (+0.51%; 95% confidence interval, –1.0 to +2.0; P =0.50). No significant treatment effects were found on secondary outcomes: left ventricular EF, peak aerobic exercise capacity, and N-terminal pro–brain natriuretic peptide ( P >0.30 for all). In predefined subgroup analyses, losartan did not have a statistically significant impact on RV EF in subgroups with symptoms, restrictive RV, RV EFP =0.045). Conclusions: Losartan had no significant effect on RV dysfunction or secondary outcome parameters in repaired tetralogy of Fallot. Future larger studies may determine whether there might be a role for losartan in specific vulnerable subgroups. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02010905.