Mineralocorticoid receptor status in the human brain after dexamethasone treatment: a single case study

BACKGROUND

Synthetic glucocorticoids like dexamethasone can cause severe neuropsychiatric effects. They preferentially bind to the glucocorticoid receptor (GR) over the mineralocorticoid receptor (MR). High dosages result in strong GR activation but likely also result in lower MR activation based on GR-mediated negative feedback on cortisol levels. Therefore, reduced MR activity may contribute to dexamethasone-induced neuropsychiatric symptoms.

OBJECTIVE

In this single case study, we evaluate whether dexamethasone leads to reduced MR activation in the human brain. Brain tissue of an 8-year-old brain tumor patient was used, who suffered chronically from dexamethasone-induced neuropsychiatric symptoms and deceased only hours after a high dose of dexamethasone.

MAIN OUTCOME MEASURES

The efficacy of dexamethasone to induce MR activity was determined in HEK293T cells using a reporter construct. Subcellular localization of GR and MR was assessed in paraffin-embedded hippocampal tissue from the patient and two controls. In hippocampal tissue from the patient and eight controls, mRNA of MR/GR target genes was measured.

RESULTS

In vitro, dexamethasone stimulated MR with low efficacy and low potency. Immunofluorescence showed the presence of both GR and MR in the hippocampal cell nuclei after dexamethasone exposure. The putative MR target gene JDP2 was consistently expressed at relatively low levels in the dexamethasone-treated brain samples. Gene expression showed substantial variation in MR/GR target gene expression in two different hippocampus tissue blocks from the same patient.

CONCLUSIONS

Dexamethasone may induce MR nuclear translocation in the human brain. Conclusions on in vivo effects on gene expression in the brain await the availability of more tissue of dexamethasone-treated patients.

Neurological Consequences of SARS-CoV-2 Infection and Concurrence of Treatment-Induced Neuropsychiatric Adverse Events in COVID-19 Patients: Navigating the Uncharted

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to the angiotensin-converting enzyme 2 (ACE2) receptor and invade the human cells to cause COVID-19-related pneumonia. Despite an emphasis on respiratory complications, the evidence of neurological manifestations of SARS-CoV-2 infection is rapidly growing, which is substantially contributing to morbidity and mortality. The neurological disorders associated with COVID-19 may have several pathophysiological underpinnings, which are yet to be explored. Hypothetically, SARS-CoV-2 may affect the central nervous system (CNS) either by direct mechanisms like neuronal retrograde dissemination and hematogenous dissemination, or via indirect pathways. CNS complications associated with COVID-19 include encephalitis, acute necrotizing encephalopathy, diffuse leukoencephalopathy, stroke (both ischemic and hemorrhagic), venous sinus thrombosis, meningitis, and neuroleptic malignant syndrome. These may result from different mechanisms, including direct virus infection of the CNS, virus-induced hyper-inflammatory states, and post-infection immune responses. On the other hand, the Guillain-Barre syndrome, hyposmia, hypogeusia, and myopathy are the outcomes of peripheral nervous system injury. Although the therapeutic potential of certain repurposed drugs has led to their off-label use against COVID-19, such as anti-retroviral drugs (remdesivir, favipiravir, and lopinavir-ritonavir combination), biologics (tocilizumab), antibiotics (azithromycin), antiparasitics (chloroquine and hydroxychloroquine), and corticosteroids (dexamethasone), unfortunately, the associated clinical neuropsychiatric adverse events remains a critical issue. Therefore, COVID-19 represents a major threat to the field of neuropsychiatry, as both the virus and the potential therapies may induce neurologic as well as psychiatric disorders. Notably, potential COVID-19 medications may also interact with the medications of pre-existing neuropsychiatric diseases, thereby further complicating the condition. From this perspective, this review will discuss the possible neurological manifestations and sequelae of SARS-CoV-2 infection with emphasis on the probable underlying neurotropic mechanisms. Additionally, we will highlight the concurrence of COVID-19 treatment-associated neuropsychiatric events and possible clinically relevant drug interactions, to provide a useful framework and help researchers, especially the neurologists in understanding the neurologic facets of the ongoing pandemic to control the morbidity and mortality.

Increased risk of dizziness in human immunodeficiency virus-infected patients taking zidovudine and efavirenz combination: a Brazilian cohort study

OBJECTIVES

Neuropsychiatric adverse effects (NPAE) related to efavirenz, mainly dizziness, is detrimental to human immunodeficiency virus (HIV) treatment. Our study aims at evaluating if zidovudine use potentiates the risk of dizziness related to efavirenz when used together and whether there are significant differences in over time distribution of this NPAE and others relatively frequents regarding efavirenz regimen without zidovudine.

METHODS

Human immunodeficiency virus-infected patients under efavirenz-containing different therapy were enrolled. A retrospective analysis of official medical records was accomplished to collect clinical data regarding NPAE occurrence and severity. Univariate statistic and statistical model based on survival analyses were performed.

KEY FINDINGS

One hundred sixty-two patients were included, of these seventy-seven (47.5%) had NPAE reported, such as dizziness (more frequent), depression and insomnia. Univariate statistical analysis demonstrated that the combined use of efavirenz with zidovudine increased the NPAE risk (OR: 2.5; P-value: 0.008), mainly dizziness risk (OR: 3.5; P-value: 0.009) and survival analysis showed that such combination is associated with dizziness occurrence faster (HR: 2.9; P-value: 0.02).

CONCLUSIONS

The results may contribute to clarify the dizziness occurrence dynamics in therapy with efavirenz and zidovudine by identifying susceptibilities and assisting in the choice of combined antiretroviral therapy.

Steroid-induced mental disorders in cancer patients: a systematic review

Corticosteroids are a central part of many cancer treatment regimens. Neuropsychiatric toxicity has complicated their use, including an association with a spectrum of symptoms, from insomnia, cognitive impairment and mood symptoms, to severe mental disorders, including mania, psychosis and severe depression. Although steroid-induced mental disorders were first reported in medicine more than 60 years ago, there is a dearth of evidence available to date on optimal treatment and prevention to guide cancer clinicians. We completed a systematic review of the current evidence for therapeutic and prophylactic interventions of steroid-induced mental disorders in cancer. We searched Medline, Embase and PsycINFO and selected studies related to steroid-induced mental disorder. The studies found were limited to case series and case reports only.

Effect of Valerian in Preventing Neuropsychiatric Adverse Effects of Efavirenz in HIV-Positive Patients: A Pilot Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

Several neuropsychiatric adverse effects of efavirenz are known. Preventing these adverse effects may improve patients' adherence to antiretroviral therapy (ART).

OBJECTIVES

To evaluate the efficacy and safety of valerian in preventing neuropsychiatric adverse effects of efavirenz in HIV-positive patients.

METHOD

In this pilot randomized, double-blinded, placebo-controlled, clinical trial, 51 HIV-positive patients who were receiving efavirenz were recruited into the valerian (n = 25) or placebo (n = 26) group. Patients received valerian (530 mg) or placebo nightly 1 hour before sleep for 4 weeks. The neuropsychiatric status (sleep, anxiety, depression, suicidal thought, and psychosis) of patients was assessed at baseline and week 4 using validated questionnaires.

RESULTS

Sleep ( P ≤ 0.001) and anxiety ( P = 0.001) significantly improved in the valerian group compared with the placebo group. Dizziness was the most common complaint of patients in first days of the intervention. In the valerian and placebo groups, 92% and 84.6% of patients experienced dizziness, respectively ( P = 0.35). Nausea was the second common adverse effect that 84% and 76.9% of patients in the valerian and placebo groups experienced ( P = 0.39).

CONCLUSION

In the first 4 weeks of ART including efavirenz, valerian significantly improved sleep and anxiety in HIV-positive patients. Valerian may be considered as a potential option in preventing neuropsychiatric adverse effects of efavirenz in HIV-positive patients.

The mechanisms of sudden-onset type adverse reactions to oseltamivir

Oseltamivir is contraindicated for people aged 10-19 in principle in Japan, due to concern about abnormal behaviours. Sudden death is another concern. This review examines growing evidence of their association and discusses underlying mechanisms of these sudden-onset type reactions to oseltamivir. First, the importance of animal models and the concept of human equivalent dose (HED) is summarized. Second, the specific condition for oseltamivir use, influenza infection, is reviewed. Third, findings from toxicity studies conducted prior to and after the marketing of oseltamivir are reported on to provide context on the observation of a possible causal association. Fourth, similarity and consistency of toxicity in humans with that in other animals is described. Finally, coherence of toxicokinetic and molecular level of evidence (channels, receptors and enzymes), including differences from the toxicity of other neuraminidase inhibitors, is reviewed. It is concluded that unchanged oseltamivir has various effects on the central nervous system (CNS) that may be related to clinical findings including hypothermia, abnormal behaviours including with fatal outcome, and sudden death. Among receptors and enzymes related to CNS action, it is known that oseltamivir inhibits nicotinic acetylcholine receptors, which are closely related to hypothermia, as well as human monoamine oxidase-A (MAO-A), which is closely related to abnormal or excitatory behaviours. Receptors such as GABAA , GABAB and NMDA and their related receptors/channels including Na+ and Ca2+ channels are thought to be other candidates for investigation related to respiratory suppression followed by sudden death and psychotic reactions (both acute and chronic), respectively.