Death Delusions and Myoclonus: Acyclovir Toxicity

A retrospective review of empiric acyclovir prescribing practices for suspected viral central nervous system infections: A single-centre study

Background

Acyclovir has an important role in the treatment of viral central nervous system (CNS) infection, especially herpes simplex virus (HSV)-1 encephalitis. It is therefore used broadly as empiric therapy for many patients who present to the hospital with symptoms of a possible neurologic infection. We sought to review our practices in acyclovir prescribing, deprescribing, and associated investigations for the clinical syndromes it treats.

Methods

Through a retrospective chart review, we identified patients prescribed acyclovir for a possible CNS infection upon admission to Vancouver General Hospital between January 1, 2019, and December 31, 2019. Patient demographics, signs, symptoms, and comorbidities were taken from admission consultation notes or discharge summaries; their investigations, including laboratory tests and imaging, were also recorded. The primary purpose was to describe the appropriateness of empiric acyclovir use in suspected meningoencephalitis cases.

Results

Among the 108 patients treated with acyclovir, 94 patients had an indication for starting empiric treatment for encephalitis or meningitis. There was suspicion and workup for encephalitis alone in 76 patients. Among discharge diagnoses, the most common was delirium of a different identified source (18 cases), followed by unknown/other (15 cases). There were seven patients whose CSF viral PCR test was positive for HSV or varicella-zoster virus (VZV); three of them had HSV-1 encephalitis. There were two total adverse events recorded attributed to acyclovir; both cases were of mild acute kidney injury.

Conclusion

We found that in many patients, acyclovir was not necessary or could have been stopped earlier, avoiding toxicity and drug costs.

Exposure-safety relationship for acyclovir in the treatment of neonatal herpes simplex virus disease

BACKGROUND

Neonatal herpes simplex virus (HSV) disease has been treated with high-dose (20 mg/kg/dose) acyclovir since 1991.

AIMS

Determine the safety of acyclovir in infants with neonatal HSV treated with high-dose acyclovir; examine the association between acyclovir dose and exposure with adverse events (AEs).

STUDY DESIGN

We obtained demographic information and acyclovir dosing via medical records. Acyclovir exposure was calculated using an established pharmacokinetic model.

SUBJECTS

Infants <120 days of age with neonatal HSV discharged from four academic children's hospitals.

OUTCOME MEASURES

We identified clinical and laboratory adverse events (AEs).

RESULTS AND CONCLUSIONS

We identified 49 infants with neonatal HSV treated with acyclovir; 42 infants had complete 21-day dosing information. Median mean daily dose was 59 mg/kg/day. Clinical AEs were common among all gestational and postnatal age groups. Rash was the most common clinical AE (37 %). Mild laboratory AEs occurred in 2-37 % of infants. The median maximum doses (mg/kg/day) were higher among infants with hypokalemia, elevated blood urea nitrogen, and thrombocytosis. For all other laboratory AEs, the median maximum doses for infants without events were higher or equal to the median maximum dose of infants with the AE. The odds of experiencing any clinical or laboratory AE did not differ by predicted acyclovir exposure for either area under the curve (AUC) or maximum concentration (Cmax) (odds ratio [OR] = 1.00 [0.98, 1.03] and OR = 1.01 [0.93, 1.12], respectively). Although AEs were common with high-dose acyclovir exposure, severe AEs were rare. Acyclovir exposure was not associated with AEs.

A medical algorithm for Cotard delusion based on more than 300 literature cases

OBJECTIVE

Cotard delusion (CD) is a rare psychiatric disorder in which the patient believes to be dead, i.e., the patient holds nihilistic delusions concerning his/her own existence. Taking into account its rarity, and possible subdiagnosis due to unawareness, most of the literature consists of case studies, complicating a more systematic approach and leading to difficulties in deciding the best clinical guidance to offer the patient suffering from CD. The objective of this work is to review the literature and propose an algorithm to help the differential diagnosis and the management of this condition.

METHOD

To do so, an extensive literature research was performed using several bibliographic databases. Since data on this topic is scarce, references in every article were cross-checked, aiming to obtain all available peer-reviewed works on CD.

RESULTS

Research resulted in 328 cases. Several treatment modalities were reported to improve the symptoms of CD, from pharmacotherapy - mainly consisting of antipsychotics and antidepressants - to electroconvulsive therapy.

CONCLUSIONS

Despite its challenging diagnosis, the delusion can be treated with readily available care. Hopefully, this work can be a useful tool to doctors when encountering this odd affliction.

An Unusual Neurological Syndrome in a Haemodialysis Patient

Advanced age and immunosuppressed states allow for complications of herpes zoster such as encephalitis. In this case report, we describe a patient with encephalopathy two days after initiation of antiviral therapy. After the necessary imaging and cerebrospinal fluid (CSF) analysis, it became evident that the neurological syndrome was due to acyclovir. Despite currently practised renal dose modification, the patient developed acyclovir-induced neurotoxicity and required intensification of his dialysis schedule to eliminate the drug. Acyclovir-induced neurotoxicity is a rare clinical presentation and presents a clinical dilemma to the physician who has to distinguish this entity from herpes zoster encephalitis and posterior circulation stroke.

Neurotoxicity associated with acyclovir and valacyclovir: A systematic review of cases

WHAT IS KNOWN AND OBJECTIVE

Acyclovir and valacyclovir are commonly used antivirals with good general tolerance. Despite their good safety profile, they can cause systemic adverse effects, such as neurotoxicity, which are less frequent and known. The objective of this review was to collect all the reported cases of neurotoxicity associated with acyclovir and valaciclovir published in the literature and characterize their clinical course and interventions.

METHODS

A systematic review of cases was carried out following the guidelines established by "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA). The research was carried out using the PubMed-Medline and Embase databases, between July 1984 and March 2021.

RESULTS AND DISCUSSION

A total of 119 cases with neurotoxicity mainly related to acyclovir (n = 88; 73.9%), followed by valaciclovir (n = 35; 29.4%) were analysed. 49.6% (n = 59) were men with a mean age of 59.5 years ± 21.1 (0.5-88). In 83.3% of the cases, renal impairment was documented and 57.1% (n = 68) with end-stage renal disease. The administered dose was higher than the renal adjustment recommendations in 59.7% of the cases. The global mean of onset of symptoms was 3.1 days ± 4.3 (0.2-28) after the start of antivirals. The mean recovery time was 9.8 days ± 21.7 (0.2-180). 74.4% of the patients had a recovery of ≤7 days, 15.9% between 8 and 15 days and 9.8% > 15 days.

WHAT IS NEW AND CONCLUSION

The neurotoxicity induced by acyclovir and its derivative valacyclovir is a poorly known and rare adverse effect that can occur mainly in patients with advanced age and impaired renal function. The most characteristic symptoms are confusion, altered level of consciousness, hallucinations, agitation and dysarthria. The basis of treatment is the discontinuation of the antiviral, and in some cases, it may require additional clearance by dialysis.

Acyclovir-induced neurotoxicity in an immunocompromised patient

This is a case report of a 75-year-old immunocompromised male who developed encephalopathy while undergoing treatment for disseminated herpes zoster with peripheral nerve involvement. While his initial presentation involved primarily profound lower extremity weakness, he developed progressive confusion to the point of obtundation only after initiation of standard therapy with intravenous acyclovir. The evaluation of his altered mental status was largely unremarkable. It was only after his acyclovir was discontinued that his symptoms resolved and he returned to his baseline mental status. His presentation was most consistent with acyclovir-induced neurotoxicity, which can present in patients with renal impairment and those who are immunocompromised.

Acyclovir Neurotoxicity in a Peritoneal Dialysis Patient: Report of a Case and Review of the Pharmacokinetics of Acyclovir

BACKGROUND The elderly population in the United States and the world is rapidly increasing. With aging, immunity and kidney function decrease, thus predisposing people to viral illnesses for which there is no effective prophylaxis. Herpes zoster afflicts the elderly and other immunocompromised patients, like those with end-stage renal disease, transplant recipients, and cancer patients, causing significant morbidity and sometimes mortality. Treating herpes zoster becomes problematic when the regular pharmacokinetics of the antiviral drugs are disturbed. CASE REPORT An 83-year-old African American man with end-stage kidney disease (ESRD) and on chronic peritoneal dialysis (PD) developed herpes zoster, for which he received the manufacturer-recommended intravenous dose of acyclovir. Shortly after taking the medication, he developed confusion, disorientation, and visual hallucinations. He was switched from PD to hemodialysis (HD), with successful recovery. Examination of the cerebrospinal fluid for meningitis and imaging studies of the head were negative. Serum levels of acyclovir were elevated. CONCLUSIONS Even when the acyclovir dose is properly adjusted for kidney function based on the current manufacturer's recommendations, it can cause neurotoxicity. Here, we discuss the pharmacokinetics of acyclovir and make some recommendations with regard to dose adjustment in patients with ESRD.

Safety of High-dose Acyclovir in Infants With Suspected and Confirmed Neonatal Herpes Simplex Virus Infections

BACKGROUND

Acyclovir is used to treat herpes simplex virus disease in infants. Treatment with high-dose acyclovir, 60 mg/kg/d, is recommended; however, the safety of this dosage has not been assessed in the past 15 years, and this dosage is not currently approved for infants by the US Food and Drug Administration.

METHODS

We included infants with neonatal herpes simplex virus disease treated with ≥14 days of intravenous acyclovir starting in the first 120 days of life admitted to 1 of 42 neonatal intensive care units managed by the Pediatrix Medical Group between 2002 and 2012. We determined the frequency and proportion of infants with clinical and laboratory adverse events (AEs) as well as the number and proportion of infant days with laboratory AEs occurring during acyclovir exposure.

RESULTS

We identified 89 infants during the study period with 1658 days of acyclovir exposure. Almost all received high-dose acyclovir therapy (79/89, 89%). The most common clinical AEs were hypotension and seizure, both occurring in 9% of infants. Thrombocytopenia was the most common laboratory AE occurring in 25% of infants and on 9% of infant-days. Elevated creatinine occurred in 2% of infants and 0.2% of infant-days and no infants developed renal failure requiring dialysis. Overall, 45% of infants had ≥1 AE.

CONCLUSIONS

In this cohort of infants treated during the high-dose acyclovir era, AEs were common but usually not severe. Many of the AEs reported in this cohort may be related to the underlying infection rather than due to acyclovir exposure.

The clinical heterogeneity of drug-induced myoclonus: an illustrated review

A wide variety of drugs can cause myoclonus. To illustrate this, we first discuss two personally observed cases, one presenting with generalized, but facial-predominant, myoclonus that was induced by amantadine; and the other presenting with propriospinal myoclonus triggered by an antibiotic. We then review the literature on drugs that may cause myoclonus, extracting the corresponding clinical phenotype and suggested underlying pathophysiology. The most frequently reported classes of drugs causing myoclonus include opiates, antidepressants, antipsychotics, and antibiotics. The distribution of myoclonus ranges from focal to generalized, even amongst patients using the same drug, which suggests various neuro-anatomical generators. Possible underlying pathophysiological alterations involve serotonin, dopamine, GABA, and glutamate-related processes at various levels of the neuraxis. The high number of cases of drug-induced myoclonus, together with their reported heterogeneous clinical characteristics, underscores the importance of considering drugs as a possible cause of myoclonus, regardless of its clinical characteristics.