Oral acyclovir induced hypokalemia and acute tubular necrosis a case report

A Rare Presentation of Herpes Simplex Virus Encephalitis With Ischemic Stroke and Associated Acyclovir-Induced Acute Kidney Injury

This case report describes a 26-year-old female presenting with clinical features of encephalitis, which progressed to ischemic stroke. In addition, she was started on intravenous acyclovir 750 mg three times a day (TID, 10 mg/kg body weight every eight hours, recommended dose), which led to the development of an acute kidney injury (AKI). Subsequently, conservative management and a reduction in the dosage of acyclovir, followed by stopping it, led to the recovery of the patient's renal function. Three days after completely stopping the drug administration, she was continued on a reduced dose of intravenous acyclovir, completing a 10-day course, with improvement in overall condition with some residual right upper limb and lower limb weakness and slurring of speech. This case signifies the importance of presentation, timely management, and prevention of acyclovir-induced AKI; in addition, it also reports a less common complication of herpes simplex virus encephalitis (HSVE), which is ischemic stroke. The management of all these herpes simplex virus (HSV-1)-related complications in a single case will add much to the existing literature.

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.

Incidence, Risk Factors and Prognosis of Hypokalaemia in Patients with Normokalaemia at Hospital Admission

Background

Hypokalaemia (K+<3.5 mmol/L) is observed in 20% of hospitalised patients. Previous studies have often dealt with the symptoms, prevalence and risk factors in hospitalised patients. Very few studies have dealt with hospital-induced hypokalaemia. The aim was to determine the incidence, predisposing risk factors and prognosis of patients developing hypokalaemia after admission.

Materials and Methods

A prospective observational study was performed for two months. Patients with at least two potassium values after admission and normal K values at admission were considered for inclusion. Clinical features, diagnoses, laboratory reports and treatment details, including antibiotics, were noted.

Results

A total of 653 patients were studied; 138 (21.1%) developed hypokalaemia. Diabetes, ischaemic heart disease (IHD), heart failure, chronic kidney disease, hypertension, chronic liver disease and chronic obstructive pulmonary disease (COPD) were the most associated comorbidities. Urea, creatinine, transaminases and neutrophilia at admission differed significantly between those with and without hypokalaemia groups. Most patients developed mild hypokalaemia (78.2%). Hypokalaemia developed mostly on the second (22.4%) and third (24.6%) days of hospitalisation. Antibiotics were used in 60% of patients. The potassium values returned to normal within 2.5 ± 1.9 days. Three patients subsequently developed hyperkalaemia.

Conclusion

Patients admitted under general medicine mostly developed mild hypokalaemia, even if they had multiple risk factors for developing hypokalaemia. Inpatient hypokalaemia had an incidence of 21%. An overwhelming majority (~88%) had at least one risk factor. Hypokalaemia was not attributed to causing mortality in any patient.

Nephrotoxicity in cancer treatment: An update

It has been estimated that nearly 80% of anticancer drug-treated patients receive potentially nephrotoxic drugs, while the kidneys play a central role in the excretion of anticancer drugs. Nephrotoxicity has long been a serious complication that hampers the effectiveness of cancer treatment and continues to influence both mortality and length of hospitalization among cancer patients exposed to either conventional cytotoxic agents or targeted therapies. Kidney injury arising from anticancer drugs tends to be associated with preexisting comorbidities, advanced cancer stage, and the use of concomitant non-chemotherapeutic nephrotoxic drugs. Despite the prevalence and impact of kidney injury on therapeutic outcomes, the field is sorely lacking in an understanding of the mechanisms driving cancer drug-induced renal pathophysiology, resulting in quite limited and largely ineffective management of anticancer drug-induced nephrotoxicity. Consequently, there is a clear imperative for understanding the basis for nephrotoxic manifestations of anticancer agents for the successful management of kidney injury by these drugs. This article provides an overview of current preclinical research on the nephrotoxicity of cancer treatments and highlights prospective approaches to mitigate cancer therapy-related renal toxicity.

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.

Acyclovir-Loaded Solid Lipid Nanoparticles: Optimization, Characterization and Evaluation of Its Pharmacokinetic Profile

Acyclovir is an antiviral drug used for the treatment of herpes simplex virus infection. Its oral bioavailability is low; therefore, frequent and high doses are prescribed for optimum therapeutic efficacy. Moreover, the current therapeutic regimen of acyclovir is associated with unwarranted adverse effects, hence prompting the need for a suitable drug carrier to overcome these limitations. This study aimed to develop solid lipid nanoparticles (SLNs) as acyclovir carriers and evaluate their in vivo pharmacokinetic parameters to prove the study hypothesis. During the SLN development process, response surface methodology was exploited to optimize the composition of solid lipid and surfactant. Optimum combination of Biogapress Vegetal 297 ATO and Tween 80 was found essential to produce SLNs of 134 nm. The oral bioavailability study showed that acyclovir-loaded SLNs possessed superior oral bioavailability when compared with the commercial acyclovir suspension. The plasma concentration of acyclovir-loaded SLNs was four-fold higher than the commercial suspension. Thus, this investigation presented promising results that the method developed for encapsulation of acyclovir offers potential as an alternative pathway to enhance the drug’s bioavailability. In conclusion, this study exhibited the feasibility of SLNs as an oral delivery vehicle for acyclovir and therefore represents a new promising therapeutic concept of acyclovir treatment via a nanoparticulate drug delivery system.

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.