The incidence, risk factors, and clinical outcomes of acute kidney injury (staged using the RIFLE classification) associated with intravenous acyclovir administration

M2 Genotype of Varicella zoster virus associated with Severe Herpes zoster in Pakistan

This case report is of herpes zoster which is caused by Varicella zoster virus (VZV). The patient was presented with acute renal failure associated with intravenous acyclovir administration for its management. A 50 years old man visited the hospital with rashes on his back. The serum sample was positive for anti-VZV IgM via Enzyme Linked Immunosorbent Assay (ELISA), and vesicular swab for VZV via polymerase chain reaction (PCR). Phylogenetic analysis identified it as M2-genotype. Patient was treated with intravenous acyclovir administration, which led to acute renal failure. Later with shift to oral acyclovir, renal functions were restored. Elderly patients with reactivation of VZV in Pakistan are at risk to contract herpes zoster. Acyclovir is drug of choice via intravenous route was found to be nephrotoxic, however oral acyclovir was safe and effective. This is first report on pathogenic VZV genotype from Pakistan and is presented to highlight that the herpes zoster cases of elderly patients' treatment option need to be revisited.

Characteristics, management and outcome of Herpes Simplex and Varicella-Zoster virus encephalitis: a multicentre prospective cohort study

OBJECTIVE

To characterize differences between Herpes Simplex virus encephalitis and Varicella-Zoster virus encephalitis (HSVE and VZVE) and other aetiologies of infectious encephalitis (IE), and to investigate the impact of time-to-aciclovir (ACV) start, ACV dose and duration on outcome.

METHODS

We compared 132 HSVE, 65 VZVE and 297 other IE enrolled in a prospective cohort (ENCEIF). We estimated associations between time-to-ACV start, dose or duration and outcome through adjusted odds ratio (aOR) using logistic regression analysis.

RESULTS

Prevalence of immunodepression differed among aetiologies: 15/65 (23%) for VZVE, 13/132 (10%) for HSVE and 30/297 (10%) for other IE (p <0.05), as was presence of seizure at admission: 27/132 (20%) for HSVE, 4/65 (6%) for VZVE and 43/297 (14%) for other IE (p <0.05). Poor outcome at hospital discharge (Glasgow outcome scale ≤3) differed among the three groups: 40/127 (31%) for HSVE, 12/65 (18%) for VZVE and 38/290 (13%) for other IE (p <0.05). Time-to-ACV start was associated with outcome in HSVE (aOR 3.61 [1.25-10.40]), but not in VZVE (aOR 0.84 [0.18-3.85]). Increased ACV dose was not associated with outcome among HSVE (aOR 1.25 [0.44-3.64]) nor VZVE (aOR 1.16 [0.24-5.73]).

DISCUSSION

HSVE and VZVE are distinct in clinical presentation, outcome and prognostic factors. The impact of early ACV initiation was more apparent for HSVE than for VZVE; however, this could be because of VZVE's smaller sample size and lower outcome rate leading to low statistical power or because of potential distinct IE pathophysiology.

Associations between Different Antivirals and Hospital-Acquired Acute Kidney Injury in Adults with Herpes Zoster

Key Points

Among intravenous antivirals, acyclovir was associated with the highest risk of hospital-acquired AKI, followed by penciclovir/ganciclovir and foscarnet. The risk of hospital-acquired AKI was dose dependent for intravenous nucleoside analogs.

Background

To examine the association of use of different antivirals with hospital-acquired AKI among Chinese adults with herpes zoster.

Methods

This study selected 3273 adult patients who received antiviral therapy for herpes zoster during hospitalization from the China Renal Data System. We identified and staged AKI using patient-level serum creatinine data according to the Kidney Disease Improving Global Outcomes criteria. We compared the relative risks of hospital-acquired AKI among patients treated with different antivirals using Cox proportional hazards models.

Results

Among 3273 patients, 1480 (45%), 681 (21%), 489 (15%), and 623 (19%) were treated with acyclovir/valacyclovir, ganciclovir, penciclovir/famciclovir, and foscarnet, respectively. During the follow-up period, a total of 111 cases of hospital-acquired AKI occurred, predominantly classified as AKI stage 1. The cumulative incidences of hospital-acquired AKI were 5%, 3%, 3%, and 1% in the patients receiving acyclovir/valacyclovir, ganciclovir, penciclovir/famciclovir, and foscarnet, respectively. Compared with acyclovir/valacyclovir, penciclovir/famciclovir/ganciclovir and foscarnet were associated with a lower risk of hospital-acquired AKI, with an adjusted hazard ratio of 0.59 (95% confidence interval [CI], 0.37 to 0.94) and 0.27 (95% CI, 0.11 to 0.63), respectively. Compared with intravenous acyclovir, intravenous penciclovir/ganciclovir and foscarnet were associated with a lower risk of hospital-acquired AKI with an adjusted hazard ratio of 0.53 (95% CI, 0.29 to 0.98) and 0.31 (95% CI, 0.12 to 0.76), respectively. The associations were consistent across various subgroups and sensitivity analyses.

Conclusions

Among antiviral therapies for herpes zoster, we found different risks of hospital-acquired AKI among the patients receiving different antivirals, in particular, those administered intravenously. Among intravenous antivirals, acyclovir was associated with the highest risk of hospital-acquired AKI, followed by penciclovir/ganciclovir and foscarnet. Confirmation studies with large samples from other populations are warranted.

Updated antimicrobial dosing recommendations for obese patients

The prevalence of obesity has increased considerably in the last few decades. Pathophysiological changes in obese patients lead to pharmacokinetic (PK) and pharmacodynamic (PD) alterations that can condition the correct exposure to antimicrobials if standard dosages are used. Inadequate dosing in obese patients can lead to toxicity or therapeutic failure. In recent years, additional antimicrobial PK/PD data, extended infusion strategies, and studies in critically ill patients have made it possible to obtain data to provide a better dosage in obese patients. Despite this, it is usually difficult to find information on drug dosing in this population, which is sometimes contradictory. This is a comprehensive review of the dosing of different types of antimicrobials (antibiotics, antifungals, antivirals, and antituberculosis drugs) in obese patients, where the literature on PK and possible dosing strategies in obese adults was critically assessed.

Acyclovir-Induced Nephrotoxicity and Neurotoxicity: A Report of Two Cases

Acyclovir is a widely used antiviral agent used to treat viral meningitis. Although well tolerated, on rare occasions, it can cause severe nephrotoxicity and neurotoxicity. It is recommended that the dose of intravenous acyclovir be calculated based on the ideal body weight for height rather than the actual weight in obese patients to avoid excessive dosage. We report two patients who developed severe acute kidney injury and neurological symptoms while on intravenous acyclovir therapy. The first patient was a 57-year-old obese woman known to have epilepsy who received a dose of intravenous acyclovir based on her actual weight of 80 kg and subsequently developed acyclovir-induced nephrotoxicity and increased seizure activity. The second patient was a 60-year-old, slightly overweight, man, who received a dose of intravenous acyclovir based on his actual weight of 80 kg and subsequently developed both acyclovir-induced nephrotoxicity and possible neurotoxicity. No other cause for the deterioration in renal function or neurological symptoms was identified, and there was rapid recovery within three days of stopping acyclovir therapy. This case report emphasizes the importance of monitoring renal function while patients are on intravenous acyclovir therapy and highlights the fact that even non-obese, overweight patients are at risk of toxicity when their actual body weight instead of their ideal body weight for height is used for intravenous acyclovir dose calculation.

A decreasing plasma concentration of a toxicologically active metabolite 9-carboxymethoxymethylguanine after dialysis - A potential new clinical biomarker for improving encephalopathy in patients treated with acyclovir

Although acyclovir is a key drug for the treatment of herpes infections, a consciousness disorder known as "acyclovir encephalopathy" is among its side effects. We encountered a patient with encephalopathy and measured the plasma and cerebrospinal fluid concentrations of acyclovir and its toxicologically active metabolite 9-carboxymethoxymethylguanine (CMMG). Before dialysis, cerebrospinal fluid concentrations of acyclovir and CMMG in this patient with a consciousness disorder were approximately 10% and 1%, respectively, of their plasma concentrations. After 3 days of dialysis, plasma CMMG levels decreased to detectable but below quantitative levels (<0.1 μg/mL), resulting in normal consciousness. These results suggest that decreasing plasma CMMG concentration could be one of clinical biomarkers for improving consciousness in patients with encephalopathy associated with acyclovir.

Fluid Stewardship of Maintenance Intravenous Fluids

Despite the frequent use of maintenance intravenous fluids (mIVF) in critically ill patients, limited guidance is available. Notably, fluid overload secondary to mIVF mismanagement is associated with significant adverse patient outcomes. The Four Rights (right drug, right dose, right duration, right patient) construct of fluid stewardship has been proposed for the safe evaluation and use of fluids. The purpose of this evidence-based review is to offer practical insights for the clinician regarding mIVF selection, dosing, and duration in line with the Four Rights of Fluid Stewardship.

Antimicrobial safety considerations in critically ill patients: part I: focused on acute kidney injury

INTRODUCTION

Antibiotic prescription is a challenging issue in critical care settings. Different pharmacokinetic and pharmacodynamic properties, polypharmacy, drug interactions, and high incidence of multidrug-resistant microorganisms in this population can influence the selection, safety, and efficacy of prescribed antibiotics.

AREAS COVERED

In the current article, we searched PubMed, Scopus, and Google Scholar for estimating renal function in acute kidney injury, nephrotoxicity of commonly used antibiotics, and nephrotoxin stewardship in intensive care units.

EXPERT OPINION

Early estimation of kidney function with an accurate method may be helpful to optimize antimicrobial treatment in critically ill patients. Different antibiotic dosing regimens may be required for patients with acute kidney injury. In many low-resource settings, therapeutic drug monitoring is not available for antibiotics. Acute kidney injury may influence treatment effectiveness and patient outcome.

Incidence, patterns, risk factors and clinical outcomes of intravenous acyclovir induced nephrotoxicity

Objectives

Acyclovir is approved to treat herpes simplex virus (HSV) type 1, type 2 and varicella-zoster virus. It is mainly eliminated via the kidneys, for which drug crystals accumulation might lead to nephrotoxicity. This study aimed to determine the incidence, risk factors, preventive measures, and clinical outcomes of acyclovir induced-nephrotoxicity.

Methods

This is a retrospective cohort study of patients >12 years of age at Sultan Qaboos University Hospital (SQUH) receiving IV acyclovir therapy between January 2016 and December 2020.

Results

Out of 191 included patients, 40 (20.1%) developed acyclovir induced-nephrotoxicity. Age (per year older: OR 1.04, 95 %CI 1.01–1.07), total duration of treatment (per day OR1.19, 95 %CI 1.06–1.33), and concomitant use of vancomycin (OR 5.96, 95 %CI 1.87–19.01) were significant independent risk factors for acyclovir induced-nephrotoxicity development. Nine patients (4.5%) died during the same hospitalization, including those three patients who required renal replacement therapy (1.5%).

Conclusion

Frequent monitoring of kidney function for older patients with concurrent use of vancomycin and IV hydration is essential to prevent IV acyclovir induced-nephrotoxicity. Antimicrobial stewardship is a crucial method to reduce the duration of treatment with IV acyclovir as appropriate.

Rapid determination of acyclovir, its main metabolite 9-carboxymethoxymethylguanine, ganciclovir and penciclovir in human serum by LC-MS/MS

A novel MS‐based analytical method for simultaneous analysis of the antiviral drugs acyclovir, its metabolite 9‐carboxymethoxymethylguanine, ganciclovir, and penciclovir in human serum is described. These antiviral drugs are active against herpes virus infections. Acyclovir and penciclovir are regarded as safe and effective medicines with mild side effects such as headache and gastrointestinal discomfort, and ganciclovir is regarded as more toxic and is known to cause, for example, bone marrow suppression. Acyclovir’s main metabolite 9‐carboxymethoxymethylguanine is a presumptive neurotoxin and should be monitored in patients with impaired renal function or in cases with neurotoxic symptoms. A sample was prepared using protein precipitation with 1% formic acid in methanol containing isotopically labeled internal standard. Chromatographic separation on a biphenyl column and mass spectrometric detection were performed in multiple reaction monitoring (MRM) mode on a Xevo TQ‐S micro with ESI in positive ion mode, within 3 min. Inter‐day assay accuracies for the quality controls varied between 95 and 104% and intra‐day assay between 93 and 105%. Inter‐day and intra‐day assay imprecision for the quality controls ranged between 1.4 and 4.2% and 1.7 and 6.5% respectively. The lower limit of quantification for all four substances was 0.156 μmol/L. It is an accurate and reproducible method for therapeutic drug monitoring.

Nutritional Risk Screening 2002 was associated with acute kidney injury and mortality in patients with acute coronary syndrome: Insight from the REACP study

BACKGROUND AND AIMS

Acute kidney injury (AKI) is a common complication of acute coronary syndrome (ACS), and is associated with increased risk of morbidity and mortality. We aimed to evaluate the impact of malnutrition risk at admission assessed using Nutritional Risk Screening 2002 (NRS-2002) on AKI and mortality in patients with ACS.

METHODS AND RESULTS

We enrolled 3185 ACS patients from the retrospective multi-centre study. AKI was defined as criteria of the 2012 Kidney Disease Improving Global Outcomes. Risk of malnutrition was defined as NRS-2002 score ≥3. The end points were AKI and all-cause mortality. There were 926 (29.1%) patients with risk of malnutrition and 481 (15.1%) patients complicated with AKI during hospitalisation, and 378 (12.0%) patients died during the 13.1 (8.5-20.4) months of follow-up. Patients with NRS-2002 score ≥3 had a higher incidence of AKI and all-cause mortality (P < 0.001). Multivariate logistic and Cox regression analysis showed that the adjusted odd ratios and hazard ratios of categorised NRS-2002 (<3 vs. ≥3) for AKI and mortality were 1.643 (95% confidence interval: 1.242-2.172, P < 0.001) and 2.026 (95% confidence interval: 1.491-2.753, P < 0.001), respectively. In structural equation modelling, the indirect effects of NRS-2002 on mortality via AKI were 54.1% (P < 0.001).

CONCLUSION

The risk of malnutrition assessed using NRS-2002 was useful in identifying high-risk patients with AKI and mortality, and patients with ACS may benefit from further nutritional intervention and prevention of AKI.

REGISTRATION NUMBER

ChiCTR1900024657.

Novel Insights to Enhance Therapeutics With Acyclovir in the Management of Herpes Simplex Encephalitis

Acyclovir is an antiviral drug poorly absorbed in the gastrointestinal tract due to its hydrophilicity, with low oral bioavailability (~20%). Although acyclovir is prescribed in the management of herpes simplex encephalitis (HSE), the disease has a poor prognosis, particularly if the treatment is delayed, reaching mortality rates of 70% if left untreated. Thus, high acyclovir doses are administered by intravenous (IV) infusion, usually at a dosage of 10 mg kg^-1 8-hourly in adults with normal renal function. However, the mortality related to HSE treated with acyclovir remains high (~20%) and permanent sequelae are commonly reported after 1 year (~50%). This review analyzed clinical trials following IV acyclovir administration. Novel insights aiming to improve drug bioavailability were reviewed, including acyclovir or its prodrugs, leading to the systemic distribution of the drug or drug targeting. Much research effort has been made to improve antiviral therapy, searching for delivery systems increasing acyclovir bioavailability by non-invasive pathways, such as oral and nasal pathways, or parenterally administered nanotechnology-based systems leading to drug targeting. Nanocarriers administered by non-invasive pathways represent feasible alternatives to treat HSE, even though not be industrially manufactured yet.

Design and Assessment of a Polyurethane Carrier Used for the Transmembrane Transfer of Acyclovir

THE Herpes simplex viruses (HSV-1, HSV-2) are responsible for a wide variety of conditions, from cutaneous-mucosal to central nervous system (CNS) infections and occasional infections of the visceral organs, some of them with a lethal end. Acyclovir is often used intravenously, orally, or locally to treat herpetic infections but it must be administered with caution to patients with kidney disease and to children of early age. The main objectives of this study were to synthesize and evaluate new polyurethane nanoparticles that might be used as proper transmembrane carriers for acyclovir. Polyurethane particles were obtained by a polyaddition process: a mixture of two aliphatic diisocyanates used as organic phase was added to a mixture of butanediol and polyethylene glycol used as aqueous phase. Two different samples (with and without acyclovir, respectively) were synthesized and characterized by UV-Vis spectra in order to assess the encapsulation efficacy and the release profile, FT-IR, DSC, SEM, and SANS for structural characterization, as well as skin irritation tests. Nearly homogeneous samples with particle sizes between 78 and 91 nm have been prepared and characterized revealing a medium tendency to form clusters and a high resistance to heat up to 300 °C. The release profile of these nanoparticles is characteristic to a drug delivery system with a late discharge of the loaded active agents. Very slight increases in the level of transepidermal water loss and erythema were found in a 15-day evaluation on human skin. The results suggest the synthesis of a non-irritative carrier with a high encapsulation efficacy that can be successfully used for the transmembrane transfer of acyclovir.

Ayurveda management of oro-facial herpes: a case report

Viral infections are one of the challenging health hazards of the present medical care. One among such viral infections is "Oro-facial Herpes", caused by the Varicella Zoster Virus (HSV-1). This case report shows the successful treatment of "Oro-facial herpes" and its complication only through Ayurveda. In which, there will be closed grouped vesicles on an erythematous base in the dermatomal pattern, with burning type of pain. The condition in Ayurveda can be co- related to 'Visarpa'. We present a case of 72-year, male, with sudden onset of edema over upper gums, with 3 to 4 vesicles over the left upper lip, left part of face within 2 days, along with reduced sensation to touch and temperature. The patient had redness, watering and burning sensation of left eye. Clinically the patient was diagnosed with "Oro- Facial Herpes". As pitta dosha and raktadhatu vitiation was noticed the case was managed by Nitya pitta rechaka (cholegogue), the dravy's with tikta, sheetaveerya and ruksha in nature. The patient showed improvement over 5 months of treatment from 10-Apr to 15-Aug-2018. The complaints of pain in the lesions reduced from 8 to 2, headache from 8 to 1 (VAS) and burning sensation reduced by 90%.

Diagnostic Challenges with Acyclovir Crystalluria - A Case Study

BACKGROUND/OBJECTIVE

Marked to abundant crystalluria may cause significant morbidity due to acute renal injury. Intravenous acyclovir administration may result in a pathologic crystalluria, especially in cases with increased renal concentration of the drug. It is important that clinical laboratory staff recognize and communicate the presence of abundant crystalluria to clinical staff to avoid irreversible kidney injury.

METHODS

We report a case of crystalluria in a patient treated empirically with intravenous acyclovir for possible viral meningitis.

RESULTS

Opaque "milky" urine was submitted for urine analysis which showed abundant long needle-shaped brightly birefringent crystals under polarized light microscopy and was diagnosed as acyclovir crystalluria.

CONCLUSIONS

Any case of moderate to abundant crystalluria should be reported in a timely manner to the clinical staff to facilitate treatment modification to reduce the risk of acute kidney injury. Laboratory staff should be aware and recognize acyclovir treatment as a possible cause of pathologic crystalluria.

Acute Kidney Injury During Treatment with Intravenous Acyclovir for Suspected or Confirmed Neonatal Herpes Simplex Virus Infection

OBJECTIVE

To describe the epidemiology of and risk factors associated with acute kidney injury (AKI) during acyclovir treatment in neonates and infants.

STUDY DESIGN

We conducted a multicenter (n = 4), retrospective cohort study of all hospitalized infants age <60 days treated with intravenous acyclovir (≥1 dose) for suspected or confirmed neonatal herpes simplex virus disease from January 2011 to December 2015. Infants with serum creatinine measured both before acyclovir (baseline) and during treatment were included. We classified AKI based on changes in creatinine according to published neonatal AKI criteria and performed Cox regression analysis to evaluate risk factors for AKI during acyclovir treatment.

RESULTS

We included 1017 infants. The majority received short courses of acyclovir (median, 5 doses). Fifty-seven infants (5.6%) developed AKI during acyclovir treatment, with an incidence rate of AKI at 11.6 per 1000 acyclovir days. Cox regression analysis identified having confirmed herpes simplex virus disease (OR, 4.35; P = .002), receipt of ≥2 concomitant nephrotoxic medications (OR, 3.07; P = .004), receipt of mechanical ventilation (OR, 5.97; P = .001), and admission to an intensive care unit (OR, 6.02; P = .006) as risk factors for AKI during acyclovir treatment.

CONCLUSIONS

Among our cohort of infants exposed to acyclovir, the rate of AKI was low. Sicker infants and those exposed to additional nephrotoxic medications seem to be at greater risk for acyclovir-induced toxicity and warrant closer monitoring.

Leflunomide increased the renal exposure of acyclovir by inhibiting OAT1/3 and MRP2

Rheumatoid arthritis patients can be prescribed a combination of immunosuppressive drug leflunomide (LEF) and the antiviral drug acyclovir to reduce the high risk of infection. Acyclovir is a substrate of organic anion transporter (OAT) 1/3 and multidrug resistance-associated protein (MRP) 2. Considering the extraordinarily long half-life of LEF's active metabolite teriflunomide (TER) and the kidney injury risk of acyclovir, it is necessary to elucidate the potential impact of LEF on the disposition of acyclovir. Here we used a specific MRP inhibitor MK571 and probenecid (OAT1/3 and MRP2 inhibitor) to assess the effects of MRP2 and OAT1/3 on the pharmacokinetics and tissue distribution of acyclovir in rats. We showed that LEF and probenecid, but not MK571 significantly increased the plasma concentration of acyclovir. However, kidney and liver exposures of acyclovir were increased when coadministered with LEF, probenecid or MK571. The kidney/plasma ratio of acyclovir was increased to approximately 2-fold by LEF or probenecid, whereas it was increased to as much as 14.5-fold by MK571. Consistently, these drugs markedly decreased the urinary excretion of acyclovir. TER (0.5-100 μmol/L) dose-dependently increased the accumulation of acyclovir in MRP2-MDCK cells with an IC₅₀ value of 4.91 μmol/L. TER (5 μmol/L) significantly inhibited the uptake of acyclovir in hOAT1/3-HEK293 cells. These results suggest that LEF/TER increased the kidney accumulation of acyclovir by inhibiting the efflux transporter MRP2, which increased its kidney/plasma ratio and renal injury risk. However, the inhibitory effects of LEF/TER on OAT1/3 reduced the tubular cells' uptake of acyclovir and increased the plasma concentration.