Amoxicillin-induced crystal nephropathy: A nationwide French pharmacovigilance databases study

Nephrotoxicity of Amoxicillin and Third-Generation Cephalosporins: An Updated Review

Because of their broad-spectrum bactericidal activity, amoxicillin (AMX) and third-generation cephalosporins (TGC) are widely used for the prophylaxis and treatment of established infections. They are considered relatively safe, but several recent reports have suggested substantial nephrotoxicity, especially with AMX use. Considering the importance of AMX and TGC for clinical practice, we conducted this up-to-date review, using the PubMed database, which focuses specifically on the nephrotoxicity of these molecules. We also briefly review the pharmacology of AMX and TGC. Nephrotoxicity of AMX may be driven by several pathophysiological mechanisms, such as a type IV hypersensitivity reaction, anaphylaxis, or intratubular and/or urinary tract drug precipitation. In this review, we focused on the two main renal adverse effects of AMX, namely acute interstitial nephritis and crystal nephropathy. We summarize the current knowledge in terms of incidence, pathogenesis, factors, clinical features, and diagnosis. The purpose of this review is also to underline the probable underestimation of AMX nephrotoxicity and to educate clinicians about the recent increased incidence and severe renal prognosis associated with crystal nephropathy. We also suggest some key elements on the management of these complications to avoid inappropriate use and to limit the risk of nephrotoxicity. While renal injury appears to be rarer with TGC, several patterns of nephrotoxicity have been reported in the literature, such as nephrolithiasis, immune-mediated hemolytic anemia, or acute interstitial nephropathy, which we detail in the second part of this review.

Incidence, associated factors, and effect on renal function of amoxicillin crystalluria in patients receiving high doses of intravenous amoxicillin (The CRISTAMOX Study): A cohort study

BACKGROUND

Amoxicillin crystalluria (AC), potentially responsible for acute kidney injury (AKI), is reported more and more frequently in patients treated with high doses of intravenous amoxicillin (HDIVA). The main objective of this study was to evaluate AC incidence in these patients. The secondary objectives were to identify factors associated with AC and to evaluate its impact on the risk of AKI.

METHODS

This multicentre, observational, cohort study was conducted between Mar 18, 2014 and Aug 16, 2019 in Dijon, Nancy, and Reims University Hospitals as well as Châlon-sur-Saône, Charleville-Mézières, and Troyes general hospitals in France. Adult patients (≥18 years) treated with HDIVA and having been tested for AC at least once during treatment were included. Clinical, biological, and therapeutic characteristics of the patients were collected. A univariable mixed logistic regression model assessed the factors associated with AC. A multivariable Cox model with AC as a time-dependent variable assessed the prognostic factors for AKI. ClinicalTrials.gov number: NCT02853292.

FINDINGS

Of the 112 included patients, 27 (24.1%, 95% CI [16.2-32.0]) developed at least one episode of AC within a mean of 5.1 days. The factors associated with its occurrence were the concomitant use of angiotensin converting enzyme (ACE) inhibitors (OR=4.6, 95% CI [2.2-9.3], p<0.0001) and the decrease of urinary pH (OR=2.1 for one pH point decrease, 95% CI [1.2-3.7], p=0.009). 20 patients (17.9%) presented with AKI, within a mean time of 10.9 days. The main factor associated with the occurrence of AKI was the occurrence of AC (aHR=7.4, 95% CI [2.5-22.2], p=0.0003).

INTERPRETATION

AC occurred in a quarter of patients treated with HDIVA and was highly prognostic of AKI.

FUNDING

None.

The Crystalline Nephropathies

Crystalline nephropathies are a unique form of kidney disease characterized by the histologic finding of intrarenal crystal deposition. The intrinsic nature of some molecules and ions combined with a favorable tubular fluid physiology leads to crystal precipitation and deposition within the tubular lumens. Crystal deposition promotes kidney injury through tubular obstruction and both direct and indirect cytotoxicities. Further kidney injury develops from inflammation triggered by these crystals. From a clinical standpoint, the crystalline nephropathies are associated with abnormal urinalysis and urinary sediment findings, tubulopathies, acute kidney injury (AKI), and/or chronic kidney disease (CKD). Urine sediment examination is often helpful in alerting clinicians to the possibility of crystal-related kidney injury. The identification of crystals within the kidneys on biopsy by pathologists prompts clinicians to evaluate patients for medication-related kidney injury, dysproteinemia-related malignancies, and certain inherited disorders. This review will focus on the clinical and pathologic aspects of these 3 categories of crystalline nephropathies.

Streptococcal and enterococcal endocarditis: time for individualized antibiotherapy?

Recommendations for the treatment of streptococcal and enterococcal endocarditis are based on old efficacy studies, but the starting doses have never been reassessed and are associated with significant adverse events. Based on data from other serious infections, we suggest that maintaining a concentration of β-lactams higher than 4-6 times the responsible bacteria MIC 100% of the time in the heart of the vegetation would be a pertinent therapeutic objective. The data point to a diffusion gradient of β-lactams in the vegetation. Yet, so far as is known, the ratio of antibiotic concentration at steady state between plasma and vegetation cannot be completely determined. Answering this crucial question would make it possible for each patient to have a targeted β-lactam plasma concentration, according to the MIC for the responsible bacteria. This would lead the way to personalized antibiotherapy and allow a safe switch to oral medication.

Crystal nephropathy and amoxicillin: insights from international spontaneous reporting systems

BACKGROUND

A substantial increase in amoxicillin-induced crystal nephropathy was recently reported in France. Our study aims to further characterize this safety issue from a worldwide perspective.

METHODS

We queried both the FDA Adverse Event Reporting System (FAERS) and the Eudravigilance databases, and performed disproportionality analysis, selecting only adverse events (AEs) related to crystal nephropathy where amoxicillin or amoxicillin/clavulanic acid were reported as suspect. In FAERS, the reporting odds ratios were calculated and deemed significant by the lower limit of the 95% confidence interval (LL95%CI) > 1, selecting all other drugs/events recorded in FAERS as comparator. Deduplication followed by case-by-case assessment and comparison between French and non-French cases were also performed in both databases.

RESULTS

Overall, 57,754 and 84,764 AE reports with amoxicillin or amoxicillin/clavulanic acid were recorded in FAERS and Eudravigilance, respectively, with France accounting for 18.7% and 22.0% of cases. Specific AEs of interest were retrieved in 144 and 239 cases, respectively. Increased reporting was found in FAERS for crystalluria (N = 99; LL95%CI 53.18), crystal nephropathy (24; 27.01), medication crystal in urine present (9; 92.00), crystal urine (8; 11.90), and crystal urine present (4; 1.57). In FAERS and Eudravigilance databases, reports were classified as serious in 98.8% and 91.2% of cases, respectively. Acute kidney injury (AKI) was found in 81.2% and 71.1% of patients. Amoxicillin was mainly given intravenously, and a dose ≥ 12 g/day was administered in 50.0% and 19.7% of cases in the FAERS and Eudravigilance databases, respectively.

CONCLUSION

Although causal association cannot be firmly inferred, a consistent signal of crystal nephropathy with amoxicillin emerged, especially in France. Clinicians should monitor patients for possible early AKI onset, especially when dealing with intravenous administration of daily doses > 12 g.

[Amoxicillin induced crystal nephropathy : Monitoring of residual plasma levels]

Since 2010, a lot of cases of amoxicillin induced crystal nephropathy have been reported to the French pharmacovigilance centers partly due to the high doses recommended by infectious disease guidelines. Typical clinical presentation and exclusion of others toxics or immuno-allergic causes are mandatory to assess the diagnostic. Amoxicillin crystals are rarely found or searched and renal biopsy is not frequently performed due to technical reasons and prompt renal recovery after antibiotics withdrawal. Monitoring of residual plasma concentration is rarely used in clinical practice for diagnostic or prognostic interest. We present 9 consecutive cases of acute kidney injury suspected to be due to amoxicillin crystals with residuals plasma levels to disclose a predictive threshold of tubulopathy. All patients had a high residual rate at diagnosis but we cannot find a threshold that would allow to adapt the antibiotic dose, enhance hydratation and alkalinizide urine to increase the medication solubility and limit renal toxicity.

Amoxicillin-induced crystal nephropathy: A nationwide French pharmacovigilance databases study

AIMS

Amoxicillin (AMX)-induced crystal nephropathy (AICN) is a rarely reported adverse drug reaction (ADR) but its increase has been recently reported in the Paris area. Our aim was to investigate the incidence, characteristics and outcome of AICN in France.

METHODS

Retrospective analysis of all AICN cases reported to the French National Pharmacovigilance Database and the Marketing Authorization Holders Pharmacovigilance Database. AICN notification rate was compared to intravenous AMX and AMX-clavulanate sales.

RESULTS

In total, 101 AICN cases were included. Intravenous AMX/AMX-clavulanate was prescribed as surgical prophylaxis (32 surgical patients) or to treat infection (69 medical patients). AKI KDIGO stage 3 was observed in 70 patients and 24/70 patients required renal replacement therapy and/or intensive care unit admission. The annual notification rate of AICN was increased by a factor of 13 since 2010 (6 [0;7] and 77 [24;111] cases per 100 000 patient-years of exposure, before and after 2010 respectively; P < .001). In surgical patients, the increase in AICN has been reported since 2010 and was mainly related to inadequate AMX administration. In medical patients, the increase in AICN was observed since 2014. After 2014, medical patients were older (67 [42;77] vs 74 years [64;84] respectively; P < .05) and were treated more frequently for endocarditis (0/20 vs 15/49 respectively; P < .01). A contributing factor was observed or suspected in 62 patients.

CONCLUSION

AICN is a severe ADR that dramatically increased in France since 2010. Assessment of AICN contributing factors and AMX drug monitoring in patients receiving high dose of AMX could reduce the risk of AICN.

High Incidence of Amoxicillin-Induced Crystal Nephropathy in Patients Receiving High Dose of Intravenous Amoxicillin

Background: Amoxicillin (AMX)-induced crystal nephropathy (AICN) is considered as a rare complication of high dose intravenous (IV) AMX administration. However, recently, its incidence seems to be increasing based on French pharmacovigilance centers. Occurrence of AICN has been observed mainly with IV administration of AMX and mostly under doses over 8 g/day. Given that pharmacovigilance data are based on declaration, the real incidence of AICN may be underestimated. Thus, the primary objective of the present study was to determine the incidence of AICN in the current practice. Materials and Methods: We conducted a retrospective study between 1 January 2015 and 31 December 2017 in Angers University Hospital. Inclusion criteria were age over 18 years-old and IV AMX administration of at least 8 g/day for more than 24 h. Patients admitted directly into the intensive care units were excluded. Medical records of patients that developed Kidney Disease:Improving Global Outcome (KDIGO) stage 2–3 acute kidney injury (AKI) were reviewed by a nephrologist and a specialist in pharmacovigilance. AICN was retained if temporality analysis was conclusive, after exclusion of other causes of AKI, in absence of other nephrotoxic drug administration. Results: A total of 1303 patients received IV AMX for at least 24 h. Among them, 358 (27.5%) were exposed to AMX doses of at least 8 g/day and were included. Patients were predominantly males (68.2%) with a mean age of 69.1 years-old. AMX was administered for a medical reason in 78.5% of cases. Patients received a median dose of AMX of 12 g/day (152.0 mg/kg/day). Seventy-three patients (20.4%) developed AKI, 42 (56.8%) of which were KDIGO stage 2 or 3. Among the latter, AICN diagnosis was retained in 16 (38.1%) patients, representing an incidence of 4.47% of total patients exposed to high IV AMX doses. Only female gender was associated with an increased risk of AICN. AMX dose was not significantly associated with AICN development. Conclusion: This study suggests a high incidence of AICN in patients receiving high IV AMX doses, representing one third of AKI causes in our study. Female gender appeared as the sole risk factor for AICN in this study.