RCTs are the gold standard for evaluating the effectiveness of medications, however, they are not the best method for identifying uncommon safety signals[28, 29]. To complement RCTs and enhance safety assessments, real-world observational studies and pharmacovigilance data mining are utilized[30]. In this study, we conducted an analysis using a comprehensive postmarketing safety surveillance database to explore any potential relationship between CAZ/AVI and its AEs, adopting a pharmacovigilance approach to collect and analyze extensive safety data.
This study illustrated that the indication ranking first was Klebsiella infection, possibly because CAZ/AVI has advantages in the treatment of Klebsiella infection[7]. Health experts (83.28%) contributed the majority of the reports; these experts are usually considered more trustworthy sources of reports. In total, 89.18% of all cases experienced severe outcomes. It should be emphasized that the serious outcomes may be correlated with the infection itself rather than with CAZ/AVI-related AEs. However, it is not clear, and it is not possible to clearly distinguish between infection-related outcomes and outcomes caused by AEs due to CAZ/AVI administration.
The disproportionality analysis revealed that “infections and infestations”, “investigations”, “renal and urinary disorders”, “hepatobiliary disorders”, and “congenital, familial and genetic disorders” were the most common and significant AEs at the SOC level. The majority of AEs associated with infection were probably brought on by infected patients' illness development rather than by CAZ/AVI therapy per se, including pathogen resistance and Candidal infections[9]. Our study identified positive signals related to liver and kidney functions, as well as to disorders of the blood and lymphatic systems. The majority of these AEs corresponded with information already documented in the medication's product label. However, when it comes to "congenital, family, and generic disorders," no positive signals met the standard at the PT level, likely due to a restricted number of case reports.
In our analysis, we also detected significant signals of AEs related to the central nervous system (CNS), including seizure, encephalopathy, epilepsy, myoclonus, status epilepticus, depressed level of consciousness, altered state of consciousness, nervous system disorder, neurotoxicity, petit mal epilepsy, generalised tonic-clonic seizure, brain oedema, and partial seizures. These AEs were not extensively mentioned in the CAZ/AVI instructions. However, our analysis results showed that AEs related to the CNS were a significant category of AEs for the drug, with a large number of related case reports being identified. These events should garner clinical attention. A study investigating the CNS adverse events associated with the use of CAZ/AVI revealed that CAZ/AVI exhibited a relatively stronger signal for nervous system disorders than did meropenem, ceftazidime, and ceftriaxone in real-world data[14]. Previous safety research revealed that the single drug ceftazidime can easily penetrate the blood‒brain barrier; however, most of the ADRs in the CNS caused by ceftazidime are transient[31]. Previous research has shown that the main risk factors for CNS-related ADRs in patients receiving antibacterial drugs include kidney failure (ceftazidime and avibactam are primarily excreted through the kidneys in their prototype), potential brain abnormalities, and CNS infections[32]. Additionally, the emerged positive signals “mental status changes” and “delirium” may be associated with the neurotoxicity of the medication or potentially linked to the patient's frailty following illness.
In our safety analysis of CAZ/AVI, we also detected several hemorrhagic AE signals, including petechiae, melaena, and shock haemorrhagic. However, our study did not find any positive signals in terms of coagulation-related test indicators. We speculate that the occurrence of bleeding AEs associated with this product may be related to thrombocytopenia to some extent. However, further studies are needed to better understand the safety characteristics related to bleeding.
Notably, hypernatremia is another newly detected significant signal, which suggests that this sodium-containing preparation may lead to excessive sodium intake in clinical practice. This medication includes approximately 146 mg of sodium per bottle (2.5 g), which accounts for 7.3% of the WHO-recommended adult daily sodium requirement of 2 g. That is, the drug (2.5 g iv q8h) will be responsible for 21.9% of the maximum daily sodium intake of adults recommended by the WHO under normal dosage. Regardless of whether the data are reliable, excessive sodium intake should undoubtedly be considered in patients on a sodium-controlled diet.
According to the study's findings, nearly half of the AE cases occurred within 1 day (n = 45, 7.17%) or within 1–3 days (n = 44, 7.07%) following the start of CAZ/AVI. The median onset time was found to be 4 days. The longest occurrence period was 55 days in 9 of the AE cases that occurred a month later. Therefore, a longer follow-up period is required to monitor the AEs of CAZ/AVI in upcoming clinical studies.
The FAERS database is considered one of the most important sources of data, and the study of spontaneous reporting systems is a valuable technique for discovering potential signals. However, our study has several limitations. First, since all the information was submitted voluntarily, the credibility of the findings may be inconsistent. Second, the data analysis did not consider several unmeasured variables that could impact AEs, such as potential drug‒drug interactions, drug combinations, and comorbidities. Third, the FAERS does not contain information about patients who took the drug without experiencing any AEs. Therefore, it is impossible to deduce the actual incidence of reported AEs from FAERS data. Fourth, we were unable to establish a precise causal link. The disproportionality study only provided an estimation of signal strength, which was statistically significant. It did not quantify risk or identify causality. Prospective clinical trials are still needed to confirm any causal connection[33]. Nevertheless, the FAERS database has been successfully utilized to analyze postmarketing pharmacovigilance studies in the past. Despite these drawbacks, these data can provide a new update for medical staff who are constantly monitoring patients who receive CAZ/AVI.