The effect of acyclovir on the tubular secretion of creatinine in vitro

Acyclovir dosing in herpes encephalitis: A scoping review

BACKGROUND

Herpes encephalitis, a rare yet potentially fatal viral infection, is treated exclusively with acyclovir, the sole antiviral medication used for this condition. Acyclovir recommended dose is 10 mg/kg/dose intravenous every 8 hours; however, it is unclear what body weight should be utilized in obese patients. Using the ideal body weight may result in subtherapeutic ineffective concentrations, while utilizing the actual body weight might result in acyclovir induced adverse effects, either nephrotoxicity or neurotoxicity or both.

OBJECTIVE

The objective of this scoping review is to explore existing evidence regarding acyclovir dosing for obese patients afflicted with herpes encephalitis.

METHODS

MEDLINE, EMBASE, Scopus, Web of Science, and CINAHL databases were searched on 26 May 2023, with no language restrictions. Two independent reviewers utilized the Covidence software to carry out the screening and selection of the articles. A total of 22 articles were included in the current review.

RESULTS

The prevalence of acyclovir-associated nephrotoxicity ranged from 13% to 21%, while the prevalence of neurotoxicity was not clearly defined. However, there is lack of evidence regarding what may arise from subtherapeutic concentrations. An approach has been suggested to help clinicians to give the most appropriate acyclovir dose to herpes encephalitis patients. Patients with normal kidney function could receive the normal doses based on actual weight if normal weight and based on adjusted body weight if obese. On the other hand, if the patients are experiencing augmented renal clearance, they could receive up to the maximum recommended doses.

CONCLUSION

Overall, there is a lack of consistency on which body weight to use to calculate acyclovir dose in obese patients. So it is recommended that further studies compare the concentration of intravenous acyclovir between obese and nonobese patients and relating the resultant concentration with patient outcomes.

Critical Review of Synthesis, Toxicology and Detection of Acyclovir

Acyclovir (ACV) is an effective and selective antiviral drug, and the study of its toxicology and the use of appropriate detection techniques to control its toxicity at safe levels are extremely important for medicine efforts and human health. This review discusses the mechanism driving ACV’s ability to inhibit viral coding, starting from its development and pharmacology. A comprehensive summary of the existing preparation methods and synthetic materials, such as 5-aminoimidazole-4-carboxamide, guanine and its derivatives, and other purine derivatives, is presented to elucidate the preparation of ACV in detail. In addition, it presents valuable analytical procedures for the toxicological studies of ACV, which are essential for human use and dosing. Analytical methods, including spectrophotometry, high performance liquid chromatography (HPLC), liquid chromatography/tandem mass spectrometry (LC-MS/MS), electrochemical sensors, molecularly imprinted polymers (MIPs), and flow injection–chemiluminescence (FI-CL) are also highlighted. A brief description of the characteristics of each of these methods is also presented. Finally, insight is provided for the development of ACV to drive further innovation of ACV in pharmaceutical applications. This review provides a comprehensive summary of the past life and future challenges of ACV.

Factors associated with acyclovir nephrotoxicity in children: data from 472 pediatric patients from the last 10 years

Acyclovir may cause acute kidney injury (AKI) due to the accumulation of relatively insoluble acyclovir crystals in renal tubules. The aim of this study was to evaluate risk factors associated with acyclovir-related AKI in children. Between January 2010 and December 2019, pediatric recipients of intravenous (IV) acyclovir were evaluated retrospectively. There were a total of 472 patients [249 (52.7%) boys] of which 32 (6.8%) had AKI [15 (46.8%) boys]. Patients with AKI had greater mean age, baseline creatinine level, and duration of treatment compared to patients without AKI (p<0.001). In the AKI group, concomitant nephrotoxic drug use was more frequent (p=0.032), and the percentage of patients treated with 1500 mg/m²/day dosage was higher (p<0.001). AKI was diagnosed at a mean of 4.3 ± 2.5 days after acyclovir initiation and creatinine levels returned to normal at a mean of 7.3 ± 3.6 days after AKI diagnosis. Only eight patients (25%) had vomiting which led to suspicion of AKI. Being older than 100.5 months (HR: 4.501, 95% CI: 1.802-11.241; p=0.001), use of 1500 mg/m²/day acyclovir (HR: 9.536, 95% CI: 2.157-42.158; p=0.003) and use of concomitant nephrotoxic drugs (HR: 5.043, 95% CI: 2.289-11.109; p<0.001) were the factors that independently increased the likelihood of nephrotoxicity.Conclusion: Most patients were asymptomatic when they were diagnosed with AKI. Clinicians should be aware of AKI risk in pediatric patients with risk factors (age >100.5 months, 1500 mg/m²/day dosage, concomitant use of nephrotoxic drugs). Acyclovir dosing should be evaluated in prospective, multicenter studies in order to identify the lowest possible therapeutic doses that do not increase AKI risk. What is Known: • Although acyclovir is mostly well tolerated, nephrotoxicity may be seen due to the accumulation of acyclovir crystals in renal tubules. • Older age, obesity, and concomitant use of other nephrotoxic drugs are reported to be risk factors for acyclovir-induced AKI in children. What is New: • In this study, pediatric patients with acyclovir-induced AKI were older, received treatment longer, received concomitant nephrotoxic drugs more commonly, and had higher acyclovir dosage and baseline creatinine levels compared to those without AKI. • Being older than 100.5 months of age, use of 1500 mg/m²/day dosage and use of nephrotoxic drugs concomitantly appear to be the prominent risk factors for AKI development in children treated with acyclovir.

Acute kidney injury (AKI) associated with intravenous aciclovir in adults: Incidence and risk factors in clinical practice

OBJECTIVES

This study sought to identify the incidence of, and risk factors for, acute kidney injury (AKI) in adults treated with parenteral aciclovir.

METHODS

A single-centre retrospective cohort study of prospectively acquired electronic clinical, pharmacy and laboratory data was performed with approval of the Caldicott guardian. AKI was defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria, prior to analysis of baseline patient and treatment-related risk factors.

RESULTS

269 aciclovir treatment episodes were identified in 268 patients. Overall incidence of AKI was 13%. Half of AKI episodes were KDIGO grade 2/3. In univariate analysis, AKI occurred more frequently in patients with pre-existing chronic kidney disease (CKD), diabetes, and in patients treated with higher daily doses of aciclovir. There was also a trend to increased age in patients with AKI. In a binomial logistic regression model only CKD and daily dose remained significant independent factors.

CONCLUSIONS

AKI is an important side effect of parenteral aciclovir, the incidence of which is comparable to established nephrotoxic drugs such as aminoglycosides. Patients with pre-existing chronic kidney disease or receiving higher total doses are at greatest risk, reinforcing the clinical importance of appropriate dose adjustment for ideal body weight and baseline renal function.

Heme oxygenase expression as a biomarker of exposure to amphiphilic polymer-coated CdSe/ZnS quantum dots

Because of their unique optical properties, quantum dots (QDs) have become a preferred system for ultrasensitive detection and imaging. However, since QDs commonly contain Cd and other heavy metals, concerns have been raised regarding their toxicity. QDs are thus commonly synthesised with a ZnS cap structure and/or coated with polymeric stabilisers. We recently synthesised amphiphilic polymer-coated tri-n-octylphosphine oxide - poly(maleic anhydride-alt-1-tetradecene (TOPO-PMAT) QDs, which are highly stable in aqueous environments. The effects of these QDs on viability and stress response in five cell lines of mouse and human origins are reported here. Human and mouse macrophages and human kidney cells readily internalised these QDs, resulting in modest toxicity. TOPO-PMAT QD exposure was highly correlated with the induction of the stress response protein heme oxygenase-1 (HMOX1). Other stress biomarkers (glutamate cysteine ligase modifier subunit, NAD(P)H, necrosis) were only moderately affected. HMOX1 may thus be a useful biomarker of TOPO-QDOT QD exposure across cell types and species.