Cardiotoxicity of chloroquine and hydroxychloroquine through mitochondrial pathway.

BACKGROUND: Medical therapies can cause cardiotoxicity. Chloroquine (QC) and hydroxychloroquine (HQC) are drugs used in the treatment of malaria and skin and rheumatic disorders. These drugs were considered to help treatment of coronavirus disease (COVID-19) in 2019. Despite the low cost and availability of QC and HQC, reports indicate that this class of drugs can cause cardiotoxicity. The mechanism of this event is not well known, but evidence shows that QC and HQC can cause cardiotoxicity by affecting mitochondria and lysosomes. METHODS: Therefore, our study was designed to investigate the effects of QC and HQC on heart mitochondria. In order to achieve this aim, mitochondrial function, reactive oxygen species (ROS) level, mitochondrial membrane disruption, and cytochrome c release in heart mitochondria were evaluated. Statistical significance was determined using the one-way and two-way analysis of variance (ANOVA) followed by post hoc Tukey to evaluate mitochondrial succinate dehydrogenase (SDH) activity and cytochrome c release, and Bonferroni test to evaluate the ROS level, mitochondrial membrane potential (MMP) collapse, and mitochondrial swelling. RESULTS: Based on ANOVA analysis (one-way), the results of mitochondrial SDH activity showed that the IC50 concentration for CQ is 20 µM and for HCQ is 50 µM. Based on two-way ANOVA analysis, the highest effect of CQ and HCQ on the generation of ROS, collapse in the MMP, and mitochondrial swelling were observed at 40 µM and 100 µM concentrations, respectively (p < 0.05). Also, the highest effect of these two drugs has been observed in 60 min (p < 0.05). The statistical results showed that compared to CQ, HCQ is able to cause the release of cytochrome c from mitochondria in all applied concentrations (p < 0.05). CONCLUSIONS: The results suggest that QC and HQC can cause cardiotoxicity which can lead to heart disorders through oxidative stress and disfunction of heart mitochondria.

Safety considerations of chloroquine in the treatment of patients with diabetes and COVID-19.

Patients with underlying diseases and coronavirus disease 2019 (COVID-19) are at increased risk of death. Using the recommended anti-COVID-19 drug, chloroquine phosphate (CQ), to treat patients with severe cases and type 2 diabetes (T2D) could potentially cause harm. We aimed to understand the safety of CQ in patients with T2D by administrating the recommended dose (63 mg/kg twice daily for 7 days) and a high dose (126 mg/kg twice daily for 7 days) of CQ in T2D rats. We found that CQ increased the total mortality of the T2D rats from 27.3% to 72.7% in the recommended and high-dose groups during the whole period. CQ also induced hematotoxicity of T2D rats in the high-dose group; the hepatic enzymes in T2D rats were significantly elevated. CQ also changed the electrocardiograms, prolonged the QTc intervals, and produced urinary leukocytes and proteins in the T2D rats. Histopathological observations revealed that CQ caused severe damage to the rats' heart, jejunum, liver, kidneys, spleen, and retinas. Furthermore, CQ significantly decreased the serum IL-1ß and IL-6 levels. In conclusion, the CQ dosage and regimen used to treat COVID-19 induced adverse effects in diabetic rats, suggesting the need to reevaluate the effective dose of CQ in humans.

Neurobehavioral, neurochemical and synaptic plasticity perturbations during postnatal life of rats exposed to chloroquine in-utero.

Despite reports that quinoline antimalarials including chloroquine (Chq) exhibit idiosyncratic neuropsychiatric effects even at low doses, the drug continues to be in widespread use during pregnancy. Surprisingly, very few studies have examined the potential neurotoxic action of Chq exposure at different points of gestation or how this phenomenon may affect neurophysiological well-being in later life. We therefore studied behavior, and the expression of specific genes and neurochemicals modulating crucial neural processes in offspring of rats exposed to prophylactic dose of Chq during different stages of gestation. Pregnant rats were injected 5 mg/kg/day (3 times) of Chq either during early- (first week), mid- (second week), late- (third week), or throughout- (all weeks) gestation, while controls received PBS injection. Behavioral characterization of offspring between postnatal days 15-20 in the open field, Y-maze, elevated plus and elevated zero mazes revealed that Chq evoked anxiogenic responses and perturbed spatial memory in rats, although locomotor activity was generally unaltered. In the prefrontal cortex (PFC), hippocampus and cerebellum of rats prenatally exposed to Chq, RT-qPCR analysis revealed decreased mRNA expression of presynaptic marker synaptophysin, which was accompanied by downregulation of postsynaptic marker PSD95. Synaptic marker PICK1 expression was also downregulated in the hippocampus but was unperturbed in the PFC and cerebellum. In addition to recorded SOD downregulation in cortical and hippocampal lysates, induction of oxidative stress in rats prenatally exposed to Chq was corroborated by lipid peroxidation as evinced by increased MDA levels. Offspring of rats infused with Chq at mid-gestation and weekly treatment throughout gestation were particularly susceptible to neurotoxic changes, especially in the hippocampus. Interestingly, Chq did not cause histopathological changes in any of the brain areas. Taken together, our findings causally link intrauterine exposure to Chq with postnatal behavioral impairment and neurotoxic changes in rats.

Ototoxicity prevention during the SARS-CoV-2 (COVID-19) emergency.

Aim of this paper is to remind the risk of ototoxicity when using chloroquine and hydroxychloroquine, in particular as prophylactic agents against SARS-CoV-2, during the pandemic. Healthy subjects taking chloroquine and hydroxychloroquine as prophylactic agents against SARS-CoV-2, during the pandemic, should be screened periodically, at least by Otoacoustic Emissions (OAEs) in order to detect early manifestations of possible cochlear ototoxic damages.

What can visual caregivers expect with patients treated for SARS-CoV-2? An analysis of ongoing clinical trials and ocular side effects.

Within the COVID-19 pandemic context, the WHO has proposed a list of medicines to treat patients with severe acute respiratory syndrome (SARS-CoV-2). An analysis of their ocular side effects was performed. Only chloroquine and hydroxychloroquine were found to have an ocular impact in the medium and long-term. Detailed search strategies were performed in EMBASE, MEDLINE, SCOPUS and WOS Core Collection. Additionally, the worldwide ongoing clinical trials including chloroquine or hydroxychloroquine were evaluated, and their proposals of drug administration and exclusion criteria analyzed. In general, high maximum cumulative doses of chloroquine or hydroxychloroquine are being used for a short period in 135 currently underway clinical trials (to 21st April 2020). Typically, the doses were 2 to 5 times greater than the AAO recommendation (adjusted to weight) to avoid toxic retinopathy, the most undesirable ocular side effect. Maximum cumulative doses up to 12,000 mg for chloroquine and 18,000 mg for hydroxychloroquine were found. In prophylaxis clinical trials, 72,000 mg and 22,500 mg were the maximum cumulative doses for hydroxychloroquine and chloroquine respectively. Only 48% of the clinical trials considered retinal impairment as an exclusion criterion, and just one referred to an ophthalmic examination previous to study inclusion. How chloroquine and hydroxychloroquine treatment affect patients with a previous retinal condition is still poorly understood. A comprehensive ophthalmological examination 6 months after treatment is recommended in this subgroup. This review provides an overview of this topic and sheds light on the challenges visual caregivers may face regarding these repurposed drugs.

Toxicity of chloroquine and hydroxychloroquine following therapeutic use or overdose.

INTRODUCTION: While chloroquine, a derivative of quinine, has been used as an antimalarial for 70 years, hydroxychloroquine is now used to treat conditions such as rheumatoid arthritis and systemic lupus erythematosus. In 2020, hydroxychloroquine (and to a lesser extent chloroquine) also received attention as a possible treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). During investigation for treating coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2, concerns for serious adverse events arose. OBJECTIVE: We review the toxicity associated with hydroxychloroquine and chloroquine use both short-term and long-term and in overdose. METHODS: Medline (via OVID) was searched from its inception through June 7 2020 using the following as either MeSH or keyword terms: ("Chloroquine/" or "Hydroxychloroquine/") AND ("Adverse Drug Event/" or "Toxicities, Drug/" or "Toxic.mp." or "Toxicity.mp." or "Overdose.mp."). We limited resultant articles to those published in English and reporting on Human subjects. This search yielded 330 articles, of which 57 were included. Articles were excluded due to lack of relevance, not reporting desired outcomes, or being duplicative in their content. Twenty-five additional articles were identified through screening references of included articles. To identify toxicities in individuals treated with hydroxychloroquine or chloroquine with COVID-19, we searched PubMed on June 10th, 2020: ("Chloroquine" or "Hydroxychloroquine") AND ("Coronavirus" or "COVID-19" or "SARS-CoV-2"). This search resulted in 638 articles. We reviewed articles for reporting of adverse events or toxicities. Most citations were excluded because they did not include original investigations or extrapolated data from subjects that did not have COVID-19; 34 citations were relevant. For the drug-interactions section, relevant classes and agents were identified through a screen of the https://www.covid19-druginteractions.org/ website. We then conducted targeted searches of PubMed up to June 7th 2020 combining "chloroquine" and "hydroxychloroquine" with terms for specific drug classes and drugs identified from the drug-interaction site as potentially relevant. We found 29 relevant articles. TOXICITY WITH SHORT-TERM USE: Gastrointestinal: Gastrointestinal toxicities are the most common to occur following initiation of chloroquine or hydroxychloroquine. Nausea, vomiting, and diarrhea account for most reported intolerances. Glucose abnormalities: Alterations in blood glucose concentrations may occur with hydroxychloroquine but are rare with standard therapeutic use. Cardiotoxicity: Short-term use can produce conduction abnormalities. Evidence from COVID-19 treatment suggests QT/QTc prolongation is of concern, particularly when used in combination with azithromycin, although disagreement exists across studies. Dermatologic: Drug eruptions or rashes, followed by cutaneous hyperpigmentation, pruritis, Stevens-Johnson syndrome, and toxic epidermal necrolysis, may occur within days to weeks of exposure but usually resolve with the discontinuation of therapy. Neuropsychiatric: Reported symptoms include confusion, disorientation, and hallucination within 24-48 h of drug initiation. Other toxicities: Hemolysis and anemia may occur in patients with glucose-6-phosphate dehydrogenase. Chloroquine treatment of COVID-19 was associated with elevation in creatine kinase and creatine kinase-MB activities with more events in the higher-dose group. TOXICITY WITH LONG-TERM USE: Retinopathy: Retinopathy is the major dose-limiting toxicity associated with long-term use; the risk is higher with increasing age, dose, and duration of usage. Cardiotoxicity: Long-term use has been associated with conduction abnormalities, cardiomyopathy, and valvular disorders. Neurotoxicity: Rarely myositis and muscle weakness, extremity weakness, and pseudoparkinsonism have been reported. TOXICITY IN OVERDOSE: Symptoms in overdose manifest rapidly (minutes to hours) and cardiotoxicity such as cardiovascular shock and collapse are most prominent. Neurotoxic effects such as psychosis and seizure may also occur. CONCLUSIONS: Hydroxychloroquine is a generally well-tolerated medication. Short-term (days to weeks) toxicity includes gastrointestinal effects and rarely glucose abnormalities, dermatologic reactions, and neuropsychiatric events. Cardiotoxicity became of increased concern with its use in COVID-19 patients. Long-term (years) toxicities include retinopathy, neuromyotoxicity, and cardiotoxicity (conduction abnormalities, cardiomyopathy). Deaths from overdoses most often result from cardiovascular collapse.

Chloroquine kills hair cells in zebrafish lateral line and murine cochlear cultures: Implications for ototoxicity.

Hearing and balance deficits have been reported during and following treatment with the antimalarial drug chloroquine. However, experimental work examining the direct actions of chloroquine on mechanoreceptive hair cells in common experimental models is lacking. This study examines the effects of chloroquine on hair cells using two common experimental models: the zebrafish lateral line and neonatal mouse cochlear cultures. Zebrafish larvae were exposed to varying concentrations of chloroquine phosphate or hydroxychloroquine for 1 h or 24 h, and hair cells assessed by antibody staining. A significant, dose-dependent reduction in the number of surviving hair cells was seen across conditions for both exposure periods. Hydroxychloroquine showed similar toxicity. In mouse cochlear cultures, chloroquine damage was specific to outer hair cells in tissue from the cochlear basal turn, consistent with susceptibility to other ototoxic agents. These findings suggest a need for future studies employing hearing and balance monitoring during exposure to chloroquine and related compounds, particularly with interest in these compounds as therapeutics against viral infections including coronavirus.

COVID-19 and toxicity from potential treatments: Panacea or poison.

Since December 2019, coronavirus disease (COVID-19) has been increasingly spreading from its origin in Wuhan, China to many countries around the world eventuating in morbidity and mortality affecting millions of people. This pandemic has proven to be a challenge given that there is no immediate cure, no vaccine is currently available and medications or treatments being used are still undergoing clinical trials. There have already been examples of self-medication and overdose. Clearly, there is a need to further define the efficacy of treatments used in the management of COVID-19. This evidence needs to be backed by large randomised-controlled clinical trials. In the meantime, there will no doubt be further off-label use of these medications by patients and practitioners and possibly related toxicity.

Cardiac safety of off-label COVID-19 drug therapy: a review and proposed monitoring protocol.

More than 2,000,000 individuals worldwide have had coronavirus 2019 disease infection (COVID-19), yet there is no effective medical therapy. Multiple off-label and investigational drugs, such as chloroquine and hydroxychloroquine, have gained broad interest due to positive pre-clinical data and are currently used for treatment of COVID-19. However, some of these medications have potential cardiac adverse effects. This is important because up to one-third of patients with COVID-19 have cardiac injury, which can further increase the risk of cardiomyopathy and arrhythmias. Adverse effects of chloroquine and hydroxychloroquine on cardiac function and conduction are broad and can be fatal. Both drugs have an anti-arrhythmic property and are proarrhythmic. The American Heart Association has listed chloroquine and hydroxychloroquine as agents which can cause direct myocardial toxicity. Similarly, other investigational drugs such as favipiravir and lopinavir/ritonavir can prolong QT interval and cause Torsade de Pointes. Many antibiotics commonly used for the treatment of patients with COVID-19, for instance azithromycin, can also prolong QT interval. This review summarizes evidenced-based data regarding potential cardiac adverse effects due to off-label and investigational drugs including chloroquine and hydroxychloroquine, antiviral therapy, monoclonal antibodies, as well as common antibiotics used for the treatment of COVID-19. The article focuses on practical points and offers a point-of-care protocol for providers who are taking care of patients with COVID-19 in an inpatient and outpatient setting. The proposed protocol is taking into consideration that resources during the pandemic are limited.

Medical treatment options for COVID-19.

Therapeutic options for coronavirus disease 2019 are desperately needed to respond to the ongoing severe acute respiratory syndrome coronavirus 2 pandemic. Both antiviral drugs and immunomodulators might have their place in the management of coronavirus disease 2019. Unfortunately, no drugs have been approved yet to treat infections with human coronaviruses. As it will take years to develop new therapies for severe acute respiratory syndrome coronavirus 2, the current focus is on the repurposing of drugs that have been approved or are in development for other conditions. Several clinical trials have already been conducted or are currently ongoing to evaluate the efficacy of such drugs. Here, we discuss the potential of these therapies for the treatment of coronavirus disease 2019.

Chloroquine and Hydroxychloroquine Retinal Toxicity Consideration in the Treatment of COVID-19.

The proposed doses of chloroquine (CQ) and hydroxychloroquine (HCQ) for treatment of COVID-19 (1000 mg/day for 10 days, CQ; 800 mg first day then 400 mg/day for 5 days, HCQ) in many guidelines worldwide, are considerably higher than the maximum recommended daily safe doses of both agents (≤2.3 mg/kg/day, CQ; ≤5.0 mg/kg/day, HCQ) for development of retinal toxicity. Irreversible retinal damage can occur if the exposure to the safe doses is >5 years. It is not known whether exposure to high doses over a short period of time can also cause the damage. We recommend that before prescribing CQ or HCQ, history of ocular disease should be obtained to avoid the prescription if appropriate. If either agent is to be used, routine baseline ocular examination is not absolutely necessary. Patients who do not have ocular disease should also be informed about the potential risk of retinal toxicity. Both agents, however, have not yet been proven to be beneficial to COVID-19.

COVID-19: Therapeutics and Their Toxicities.

SARS-CoV-2 is a novel coronavirus that emerged in 2019 and is causing the COVID-19 pandemic. There is no current standard of care. Clinicians need to be mindful of the toxicity of a wide variety of possibly unfamiliar substances being tested or repurposed to treat COVID-19. The United States Food and Drug Administration (FDA) has provided emergency authorization for the use of chloroquine and hydroxychloroquine. These two medications may precipitate ventricular dysrhythmias, necessitating cardiac and electrolyte monitoring, and in severe cases, treatment with epinephrine and high-doses of diazepam. Recombinant protein therapeutics may cause serum sickness or immune complex deposition. Nucleic acid vaccines may introduce mutations into the human genome. ACE inhibitors and ibuprofen have been suggested to exacerbate the pathogenesis of COVID-19. Here, we review the use, mechanism of action, and toxicity of proposed COVID-19 therapeutics.