Doses Of Chloroquine Research Articles

SARS-Cov-2 Viral Kinetics in Mild COVID-19 Patients Treated with Chloroquine Regimens or Standard of Care

This study measures the impact of chloroquine (CQ) therapy in reducing SARS-CoV-2 viral load in infected individuals and hence its transmissibility by describing changes in nasopharyngeal SARS-CoV-2 RNA kinetics in patients receiving standard of care (SOC) or CQ +/- ritonavir-boosted lopinavir (LPV/r). The nasopharyngeal (NP) samples were collected from mild COVID-19 patients admitted at Bamrasnaradura Infectious Diseases Institute between March and April of 2020. These patients either received SOC, or a high dose of CQ with loading dose, or high dose of CQ plus LPV/r. The samples were tested at AFRIMS using a quantitative RT-PCR assay. Levels of CQ in the plasma were measured 6 days post initiation of their treatment. In some instances, viral isolation was attempted to determine SARS-CoV-2 viability. Analyses of the clinical outcomes showed that CQ +/- lopinavir did not contribute significantly to decreasing the number of days with detected SARS-CoV-2 RNA. Viral NP GEs declined faster in the CQ group, but benefits diminished rapidly with delays in treatment initiation. Funding Global Emerging Infections Surveillance, Armed Forces Health Surveillance Branch (GEIS-AFHSB) for all research-related activities at the AFRIMS

Comparative effectiveness and safety of 32 pharmacological interventions recommended by guidelines for coronavirus disease 2019: a systematic review and network meta-analysis combining 66 trials.

Background:The global pandemic coronavirus disease 2019 (COVID-19) has become a major public health problem and presents an unprecedented challenge. However, no specific drugs were currently proven. This study aimed to evaluate the comparative efficacy and safety of pharmacological interventions in patients with COVID-19.Methods:Medline, Embase, the Cochrane Library, and clinicaltrials.gov were searched for randomized controlled trials (RCTs) in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)/SARS-CoV. Random-effects network meta-analysis within the Bayesian framework was performed, followed by the Grading of Recommendations Assessment, Development, and Evaluation system assessing the quality of evidence. The primary outcome of interest includes mortality, cure, viral negative conversion, and overall adverse events (OAEs). Odds ratio (OR) with 95% confidence interval (CI) was calculated as the measure of effect size.Results:Sixty-six RCTs with 19,095 patients were included, involving standard of care (SOC), eight different antiviral agents, six different antibiotics, high and low dose chloroquine (CQ_HD, CQ_LD), traditional Chinese medicine (TCM), corticosteroids (COR), and other treatments. Compared with SOC, a significant reduction of mortality was observed for TCM (OR = 0.34, 95% CI: 0.20–0.56, moderate quality) and COR (OR = 0.84, 95% CI: 0.75–0.96, low quality) with improved cure rate (OR = 2.16, 95% CI: 1.60–2.91, low quality for TCM; OR = 1.17, 95% CI: 1.05–1.30, low quality for COR). However, an increased risk of mortality was found for CQ_HD vs. SOC (OR = 3.20, 95% CI: 1.18–8.73, low quality). TCM was associated with decreased risk of OAE (OR = 0.52, 95% CI: 0.38–0.70, very low quality) but CQ_HD (OR = 2.51, 95% CI: 1.20–5.24) and interferons (IFN) (OR = 2.69, 95% CI: 1.02–7.08) vs. SOC with very low quality were associated with an increased risk.Conclusions:COR and TCM may reduce mortality and increase cure rate with no increased risk of OAEs compared with standard care. CQ_HD might increase the risk of mortality. CQ, IFN, and other antiviral agents could increase the risk of OAEs. The current evidence is generally uncertain with low-quality and further high-quality trials are needed.

Pharmacological Study of Andrographis paniculata (Kalmegh) for their possible Antimalarial Activity with Emphasis on Resistance and Resistant Reversal

Antimalarial effect of some medicinal plants found in Uttarakhand (India) is least explored by the scientific community locally. Advent of resistance to various antimalarial drugs by plasmodium made malaria more fatal and life-threatening disease. Therefore, present need is to invest more effort and interest in research for antimalarials from medicinal plants. Plasmodium yoelii nigeriensis (PYn) is multi drug resistance malaria parasite known for resistance to chloroquine (CQ), quinine, quinidine, amodiaquine, halofantrine, mepacrine, and mefloquine. The P. yoelii produces 100% infections in animals. Researchers in this study tried to understand the behavior of CQ -resistant plasmodium PYn with CQ, whole plant extracts of Andrographis paniculata (AP) with possibility of their resistance reversal. Wherever, 3–4 times CQ doses are not able to produce sufficient antimalarial effect in resistant PYn. Most of the pure plant extracts are also not able to produce minimal therapeutic response when given alone. Whereas, plant extract shows a better effect when given with minimal dose CQ than alone. AP whole plant hydroalcoholic (HA) extract doses 300 mg/kg when combining CQ 20 mg/kg shows the best effect among the other extracts alone. Parasitemia and red blood cells count parameters significantly improved. Hemoglobin, survival days and weight are benefitted with HA extract then ethanolic extract. Unexpectedly, HA extract at higher dosage 1000 mg/kg produce efficacy then 300 mg/kg dose group. Higher doses of HA extract causes some sort of negative effect on almost all selected parameters even though with ethanolic extract. Present approach of multi-drug dosage supports also supported here in the study with a thought of using antimalarial plant extracts during regular malaria treatment. Genesis of idea of referring standardized plant extract(s) in combination as oral dosage with prophylactic (travelers) malaria and malaria treatment or side-food for malaria will also possible. Positive results may pave a path for inclusion of herbal extracts or herbs as side treatment or resistance-breaker food for malaria.

Efficient pre-treatment for pancreatic cancer using chloroquine-loaded nanoparticles targeting pancreatic stellate cells.

Pancreatic stellate cells (PSCs) play a key role in desmoplastic stroma, which is a characteristic of pancreatic ductal adenocarcinoma (PDAC), and they also enhance the malignancy of pancreatic cancer cells. Our previous study reported chloroquine's mitigating effects on PSC activation; however, the drug is known to induce adverse effects in clinical practice. The present study aimed to reduce chloroquine doses and develop a useful pre-treatment that targets PSCs using nanoparticles. Poly lactic-co-glycolic acid (PLGA) nanoparticles were used as carriers and loaded with indocyanine green (Nano-ICG) or chloroquine (Nano-CQ). Tumor accumulation of Nano-ICG was evaluated using an in vivo imaging system. The effects of chloroquine, Nano-CQ and/or chemotherapy drug gemcitabine were investigated in an orthotopic xenograft mouse model. Nano-ICG selectively accumulated in pancreatic tumors and persisted therein for over 7 days after administration. Additionally, Nano-ICG accumulated in the peritoneal metastasized regions, but not in the liver, kidney and normal pancreatic tissues. Nano-CQ reduced the density of activated PSCs at lower chloroquine doses and significantly restrained tumor progression in combination with gemcitabine. In conclusion, the PLGA nanosystem successfully delivered the drug to pancreatic tumors. Nano-CQ efficiently reduced PSC activation and may be a promising novel pre-treatment strategy for PDAC.

Analytical quality by design approach for the control of potentially counterfeit chloroquine with some NSAIDS using HPLC with fluorescence detection in pharmaceutical preparation and breast milk

AbstractChloroquine phosphate (CQ) the antimalarial drug and suggested to treat the pandemic disease coronavirus (COVID-19) is often adulterated with some of the non-steroidal anti-inflammatory drugs (NSAIDs) such as paracetamol, aspirin (ASP), or both. The purpose of this study is to detect such counterfeited drugs, using a reversed phase high pressure liquid chromatography (RP-HPLC) method with fluorescence detection. Analysis was divided into three phases. In the first phase, a Plackett-Burman design (PBD) was used to screen five independent factors, namely, buffer pH, buffer concentration (mM), acetonitrile content (%), flow rate (mL/min) and triethylamine (TEA) content in the buffer preparation (%). The selected dependent variables were (resolution, symmetry of peaks and run time). The objective of the second phase was to optimize the method performance using Box-Behnken design (BBD) and desirability function for multiple response optimization to obtain the best chromatographic performance with the shortest run time. Optimal chromatographic separation was achieved on a YMC-pack pro C18 ODS-A column (15 cm × 4.6 mm, 5 µm) at room temperature The optimum mobile phase consisted of acetonitrile and 5 mM sodium dihydrogen phosphate buffer containing 0.5% triethyamine (30:70, v/v) with the pH adjusted to 3.5 using an orthophosphoric acid solution. The flow rate was maintained at 1 mL/min, and the detection was performed with a fluorescence detector fixed at 380 nm (λemission) after excitation at 335 nm (λexcitation). The third phase was method validation according to ICH guidelines, providing to be specific, precise, accurate, and robust. The method is linear over a range of 0.4–8 µg/mL for chloroquine and ASP, while for paracetamol it is linear over 16–48 µg/mL. The developed RP-HPLC method was used for quantitation of the three drugs in chloroquine dosage form samples. The method shows a great tendency in the classification between the genuine chloroquine and the adulterated ones in pharmaceutical preparations and breast milk.

Treatment with chloroquine is retinotoxic in captive African penguins (Speniscus demersus). Attenuation and recovery of electroretinographic responses.

To evaluate the effect of prophylactic anti-malarial chloroquine treatment, and its cessation, on electroretinographic (ERG) responses of captive African penguins. A brief ERG protocol ("QuickRetCheck") was recorded under mesopic conditions with manual restraint and no sedation or pupil dilation. Birds were recorded on two separate occasions, first while being treated with a daily chloroquine dose of 10mg/kg for 12days (n=15, treatment group) and second after 4months without chloroquine treatment (n=6, off-treatment group). Three birds were recorded on both occasions. Three other birds from the flock that died were studied histopathologically. Scotopic responses were unmeasurable in either recording and therefore were not analyzed. Mean a- and b-wave amplitudes of the mixed rod-cone responses to standard (3cd·s/m2 ) and high (10cd·s/m2 ) intensity flashes were higher in the off-treatment group. No difference in implicit times was observed. Sex, age, and number of previous chloroquine treatments did not affect ERG responses. Histopathology revealed Plasmodium spp.in the lungs, liver, and brain, but not in the eyes, of the necropsied birds, and there were no signs of retinitis or retinopathy. Daily chloroquine treatment was associated with attenuated ERG responses in penguins, which improve following cessation of treatment. Further work is warranted to establish a chloroquine dose that is efficacious yet has minimal adverse effects. Our results suggest that ERG responses of captive penguins undergoing ERG for any indication (such as prior to cataract surgery), must be evaluated in light of the birds' anti-malaria treatment status.

Chloroquine, an Anti-Malaria Drug as Effective Prevention for Hantavirus Infections

We investigated whether chloroquine can prevent hantavirus infection and disease in vitro and in vivo, using the Hantaan virus newborn C57BL/6 mice model and the Syrian hamster model for Andes virus. In vitro antiviral experiments were performed using Vero E6 cells, and Old World and New World hantavirus species. Hantavirus RNA was detected using quantitative RT-PCR. For all hantavirus species tested, results indicate that the IC50 of chloroquine (mean 10.2 ± 1.43 μM) is significantly lower than the CC50 (mean 260 ± 2.52 μM) yielding an overall selectivity index of 25.5. We also investigated the potential of chloroquine to prevent death in newborn mice after Hantaan virus infection and its antiviral effect in the hantavirus Syrian hamster model. For this purpose, C57Bl/6 mother mice were treated subcutaneously with daily doses of chloroquine. Subsequently, 1-day-old suckling mice were inoculated intracerebrally with 5 x 102 Hantaan virus particles. In litters of untreated mothers, none of the pups survived challenge. The highest survival rate (72.7% of pups) was found when mother mice were administered a concentration of 10 mg/kg chloroquine. Survival rates declined in a dose-dependent manner, with 47.6% survival when treated with 5 mg/kg chloroquine, and 4.2% when treated with 1 mg/kg chloroquine. Assessing the antiviral therapeutic and prophylactic effect of chloroquine in the Syrian hamster model was done using two different administration routes (intraperitoneally and subcutaneously using an osmotic pump system). Evaluating the prophylactic effect, a delay in onset of disease was noted and for the osmotic pump, 60% survival was observed. Our results show that chloroquine can be highly effective against Hantaan virus infection in newborn mice and against Andes virus in Syrian hamsters.

4-Chlorothymol Exerts Antiplasmodial Activity Impeding Redox Defense System in Plasmodium falciparum

Malaria remains one of the major health concerns due to the resistance of Plasmodium species toward the existing drugs warranting an urgent need for new antimalarials. Thymol derivatives were known to exhibit enhanced antimicrobial activities; however, no reports were found against Plasmodium spp. In the present study, the antiplasmodial activity of thymol derivatives was evaluated against chloroquine-sensitive (NF-54) and -resistant (K1) strains of Plasmodium falciparum. Among the thymol derivatives tested, 4-chlorothymol showed potential activity against sensitive and resistant strains of P. falciparum. 4-Chlorothymol was found to increase the reactive oxygen species and reactive nitrogen species level. Furthermore, 4-chlorothymol could perturb the redox balance by modulating the enzyme activity of GST and GR. 4-Chlorothymol also showed synergy with chloroquine against chloroquine-resistant P. falciparum. 4-Chlorothymol was found to significantly suppress the parasitemia and increase the mean survival time in in vivo assays. Interestingly, in in vivo assay, 4-chlorothymol in combination with chloroquine showed higher chemosuppression as well as enhanced mean survival time at a much lower concentration as compared to individual doses of chloroquine and 4-chlorothymol. These observations clearly indicate the potential use of 4-chlorothymol as an antimalarial agent, which may also be effective in combination with the existing antiplasmodial drugs against chloroquine-resistant P. falciparum infection. In vitro cytotoxicity/hemolytic assay evidently suggests that 4-chlorothymol is safe for further exploration of its therapeutic properties.

Zinc-related Treatments Combined with Chloroquine and Gemcitabine for Treating Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers, with a 10% 5-year survival rate. A prominent issue with the treatment mainly used today, gemcitabine, is that it is unable to penetrate the stroma around the pancreatic cancer tumor. The stroma is a dense network of cells that promotes cancer development and metastasis and creates difficulty for chemotherapy treatments to be delivered effectively to the tumor. Targeting the pathways responsible for both the stroma (namely the Hedgehog signaling pathway) and the tumor (the Ras/MAPK pathway) could potentially lead to more effective treatments. The dysregulation of zinc has been implicated in disease progression through these pathways, however its exact effect is unclear. TPEN is a metal ion chelator that is able to induce zinc deficiency. We hypothesized that if various dosages of TPEN and zinc are used in combination with Chloroquine and Gemcitabine, then combinations of medium to high doses of zinc, Chloroquine, and Gemcitabine will be the most effective at reducing cell proliferation. Several treatment combinations were created in a drug matrix and tested using a cell proliferation assay. To mimic the stroma-tumor interaction that would occur in vivo, we took the conditioned medium from pancreatic cancer associated fibroblasts (mCAF) and cultured pancreatic cancer cells (PANC-1). The results showed that while TPEN was able to significantly lower cell proliferation, it was not more effective than the current treatment. However, when combined with Chloroquine and Gemcitabine, zinc and TPEN both significantly lowered cell proliferation compared to Gemcitabine, suggesting a synergistic effect that resulted in a more cytotoxic treatment. Further research and clinical trials on this topic are needed to determine whether this could be a viable treatment for pancreatic cancer. This repurposed treatment could potentially increase survival rates and become a more affordable alternative to novel drug development.

Beta-Adrenergic Receptor Stimulation Modulates the Cellular Proarrhythmic Effects of Chloroquine and Azithromycin.

The antimalarial drug, chloroquine (CQ), and antimicrobial drug, azithromycin (AZM), have received significant attention during the COVID-19 pandemic. Both drugs can alter cardiac electrophysiology and have been associated with drug-induced arrhythmias. Meanwhile, sympathetic activation is commonly observed during systemic inflammation and oxidative stress (e.g., in SARS-CoV-2 infection) and may influence the electrophysiological effects of CQ and AZM. Here, we investigated the effect of beta-adrenergic stimulation on proarrhythmic properties of CQ and AZM using detailed in silico models of ventricular electrophysiology. Concentration-dependent alterations in ion-channel function were incorporated into the Heijman canine and O’Hara-Rudy human ventricular cardiomyocyte models. Single and combined drug effects on action-potential (AP) properties were analyzed using a population of 1,000 models accommodating inter-individual variability. Sympathetic stimulation was simulated by increasing pacing rate and experimentally validated isoproterenol (ISO)-induced changes in ion-channel function. In the canine ventricular model at 1 Hz pacing, therapeutic doses of CQ and AZM (5 and 20 μM, respectively) individually prolonged AP duration (APD) by 33 and 13%. Their combination produced synergistic APD prolongation (+161%) with incidence of proarrhythmic early afterdepolarizations in 53.5% of models. Increasing the pacing frequency to 2 Hz shortened APD and together with 1 μM ISO counteracted the drug-induced APD prolongation. No afterdepolarizations occurred following increased rate and simulated application of ISO. Similarly, CQ and AZM individually prolonged APD by 43 and 29% in the human ventricular cardiomyocyte model, while their combination prolonged APD by 76% without causing early afterdepolarizations. Consistently, 1 μM ISO at 2 Hz pacing counteracted the drug-induced APD prolongation. Increasing the ICa,L window current produced afterdepolarizations, which were exacerbated by ISO. In both models, reduced extracellular K+ reduced the repolarization reserve and increased drug effects. In conclusion, CQ- and AZM-induced proarrhythmia is promoted by conditions with reduced repolarization reserve. Sympathetic stimulation limits drug-induced APD prolongation, suggesting the potential importance of heart rate and autonomic status monitoring in particular conditions (e.g., COVID-19).

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.

Mass radical treatment of a group of foreign workers to mitigate the risk of re-establishment of malaria in Sri Lanka

BackgroundFollowing malaria elimination, Sri Lanka was free from indigenous transmission for six consecutive years, until the first introduced case was reported in December 2018. The source of transmission (index case) was a member of a group of 32 migrant workers from India and the location of transmission was their residence reporting a high prevalence of the primary vector for malaria. Despite extensive vector control the situation was highly susceptible to onward transmission if another of the group developed malaria. Therefore, Mass Radical Treatment (MRT) of the group of workers for Plasmodium vivax malaria was undertaken to mitigate this risk.MethodThe workers were screened for malaria by microscopy and RDT, their haemoglobin level assessed, and tested for Glucose 6 phosphate dehydrogenase deficiency (G6PD) using the Care Start RDT and Brewers test prior to treatment with chloroquine (CQ) 25 mg/kg body weight (over three days) and primaquine (PQ) (0.25 mg/kg/day bodyweight for 14 days) following informed consent. All were monitored for adverse events.ResultsNone of the foreign workers were parasitaemic at baseline screening and their haemoglobin levels ranged from 9.7–14.7 g/dl. All 31 individuals (excluding the index case treated previously) were treated with the recommended dose of CQ. The G6PD test results were inconclusive in 45% of the RDT results and were discrepant between the two tests in 31% of the remaining test events. Seven workers who tested G6PD deficient in either test were excluded from PQ and the rest, 24 workers, received PQ. No serious adverse events occurred.ConclusionsMass treatment may be an option in prevention of reintroduction settings for groups of migrants who are likely to be carrying latent malaria infections, and resident in areas of high receptivity. However, in the case of Plasmodium vivax and Plasmodium ovale, a more reliable and affordable point-of-care test for G6PD activity would be required. Most countries which are eliminating malaria now are in the tropical zone and face considerable and similar risks of malaria re-introduction due to massive labour migration between them and neighbouring countries. Regional elimination of malaria should be the focus of global strategy if malaria elimination from countries is to be worthwhile and sustainable.

Chloroquine combined with concurrent radiotherapy and temozolomide for newly diagnosed glioblastoma: a phase IB trial

ABSTRACT Treatment of glioblastoma xenografts with chloroquine results in macroautophagy/autophagy inhibition, resulting in a reduction of tumor hypoxia and sensitization to radiation. Preclinical data show that EGFRvIII-expressing glioblastoma may benefit most from chloroquine because of autophagy dependency. This study is the first to explore the safety, pharmacokinetics and maximum tolerated dose of chloroquine in combination with radiotherapy and concurrent daily temozolomide in patients with a newly diagnosed glioblastoma. This study is a single-center, open-label, dose-finding phase I trial. Patients received oral chloroquine daily starting one week before the course of chemoradiation (temozolomide 75 mg/m2/d) until the end of radiotherapy (59.4 Gy/33 fractions). Thirteen patients were included in the study (n = 6: 200 mg, n = 3: 300 mg, n = 4: 400 mg chloroquine). A total of 44 adverse events, possibly related to chloroquine, were registered including electrocardiogram QTc prolongation, irreversible blurred vision and nausea/vomiting resulting in cessation of temozolomide or delay of adjuvant cycles. The maximum tolerated dose was 200 mg chloroquine. Median overall survival was 16 months (range 2–32). Median survival was 11.5 months for EGFRvIII- patients and 20 months for EGFRvIII+ patients. A daily dose of 200 mg chloroquine was determined to be the maximum tolerated dose when combined with radiotherapy and concurrent temozolomide for newly diagnosed glioblastoma. Favorable toxicity and promising overall survival support further clinical studies. Abbreviations: AE: adverse events; CQ: chloroquine; DLT: dose-limiting toxicities; EGFR: epidermal growth factor receptor; GBM: glioblastoma; HCQ: hydroxychloroquine; IDH1/2: isocitrate dehydrogenase (NADP(+)) 1/2; MTD: maximum tolerated dose; CTC: National Cancer Institute Common Toxicity Criteria; MGMT: O-6-methylguanine-DNA methyltransferase; OS: overall survival; po qd: per os quaque die; SAE: serious adverse events; TMZ: temozolomide; WHO: World Health Organization

Exposure to chloroquine in male adults and children aged 9-11 years with malaria due to Plasmodium vivax.

Chloroquine is effective against the asexual blood stage of Plasmodium vivax. A high proportion of children are underdosed with the drug, but there are no studies comparing chloroquine exposure in adults and children aged 8-11 years old. The present study intends to compare these populations using the area under the curve (AUC) derived from the plasma concentration-time profile in patients with P. vivax. A prospective study of cases was performed on male children (aged 9-11 years) and adults with vivax malaria. Blood samples were collected after several days of treatment. Chloroquine was measured by high-performance liquid chromatography. A non-compartmental pharmacokinetic model was used to calculate the pharmacokinetic parameters of the drug. A total of 20 children and 25 adults were included in the study. Plasma concentrations of chloroquine in older children ranged from 67 to 1112 ng/ml, and in adults the value ranged from 74 to 1147 ng/ml. The AUC to the last measurable concentration and to infinite was significantly lower in children than in adults, indicating a lower exposure to the drug. These data demonstrate lower exposure to chloroquine in children, which corroborates the importance of optimising the doses of chloroquine in the study age band to ensure adequate exposure to the drug.

Abstract 1236: In vitro association of chloroquine with alkylating and antimicrotubule agents in patient derived cell lines of glioblastoma

Abstract Autophagy is an important mechanism for cell survival after chemotherapy treatment. Many preclinical and clinical trials have tried to achieve tumor remission combining alkylating agents with autophagy inhibition. Chloroquine (CQ) has a long record as an autophagy inhibitor. In previous studies it was administered in vitro with mixed effects on central nervous system cell lines: while high doses of CQ were cytotoxic, low doses were neuroprotective. Preclinical studies showed that CQ could be used to treat glioblastoma, tumors derived from glial cells in the brain. In a phase I/II clinical trial combining CQ with the standard alkylating agent (temozolomide) plus radiotherapy treating patients with glioblastoma, a dose-limiting toxicity was observed at high doses. Although the authors reported that autophagy inhibition could not be achieved, they did not describe if this mechanism was involved in tumor resistance in that cohort of patients. In order to clarify if CQ can be used to block autophagy, we performed long term treatment combining low doses of CQ with chemotherapeutic agents. We used patient derived cell lines (PDCL) from glioblastoma tumors and treated them with therapeutic agents, using the reported plasma concentration of each drug. We measured acidic organelles with acridine orange incorporation 3, 5 and 7 days after addition of the treatment with flow cytometry. Additionally, 7 days after treatment surviving cells were counted. We did not observe significant increase in autophagy levels or decrease in cell number after temozolomide treatment. On the contrary, paclitaxel induced autophagy and decreased cell survival. Interestingly the combination of procarbazine, lomustine and vincristine (PCV), induced a broad range of results, ranging from high autophagy to increased cell death. We decided to combine PCV with CQ and perform long term analysis in order to evaluate the ability of cells undergoing or escaping apoptosis, senescence or mitotic catastrophe. After 5 days nuclear morphometric analysis demonstrated that out of 6 PDCL tested, only one presented an increase in senescence. The same PDCL also presented a decrease in total number of cells and increase in p62, although combining CQ with PCV was not better than PCV alone. Our results in vitro, using low concentrations of CQ corroborate the finding in clinical trials that chloroquine does not eliminate malignant cells in glioblastoma and better autophagy inhibitors need to be developed to achieve this goal. Citation Format: Franciele C. Kipper, Ajith Thomas, Guido Lenz. In vitro association of chloroquine with alkylating and antimicrotubule agents in patient derived cell lines of glioblastoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1236.

The extent of chloroquine underdosing in adult patients with malaria by Plasmodium vivax from an endemic area of the Brazilian Amazon basin.

To evaluate the extent of chloroquine underdosing and to measure the concentrations of chloroquine and desethylchloroquine in adult patients with P. vivax malaria in the Brazilian Amazon basin. Prospective study of cases in male adult patients with malaria by Plasmodium vivax treated with a total dose of 1500mg chloroquine over three days and a short course of primaquine. Patients were weighed at admission, and the dose per mg/kg was determined. Blood samples were collected at 24 and 168h after enrolment, and the concentrations of chloroquine and desethylchloroquine were measured in plasma by high-performance liquid chromatography with fluorescence detection. Of 61 patients were included in the study, and 60% received a total dose of chloroquine below 25mg/kg. Plasma chloroquine concentrations ranged from 90 to 184ng/ml and from 175 to 827ng/ml at 24 and 168hours. For desethylchloroquine, the values ranged from 32 to 144ng/ml and from 90 to 440ng/ml at 24 and 168h. There were no significant correlations between the plasma levels of chloroquine and the doses administered (mg/kg) at 24 and 196h. Similar results were found for desethylchloroquine. There is widespread suboptimal dosing of chloroquine that is probably due to the dosing regimen based on patient age, which reduces the drug exposure with a possible influence on parasite clearance.

The risk of QTc-interval prolongation in COVID-19 patients treated with chloroquine.

BackgroundChloroquine, a quinolone antimalarial drug, is known to potentially inhibit pH-dependent viral replication of the SARS-CoV‑2 infection. Therefore, chloroquine is considered as a treatment option for coronavirus disease 2019 (COVID-19). Chloroquine is known for prolonging the QT interval, but limited data are available on the extent of this QT-prolonging effect.ObjectiveTo assess the QTc-prolonging potential of chloroquine in COVID-19 patients and to evaluate whether this prolongation increases with the cumulative dose of chloroquine and is associated with the peak plasma concentration of chloroquine. Furthermore, the number of patients who prematurely discontinued treatment or had an adjustment in dose due to QTc-interval prolongation was established.MethodsA retrospective, observational study was performed in patients aged over 18 years, hospitalised for a suspected or proven infection with COVID-19, and therefore treated with chloroquine, with a baseline electrocardiogram (ECG) performed prior to the start of treatment and at least one ECG after starting the treatment.ResultsIn total, 397 patients were included. The mean increase in QTc interval throughout the treatment with chloroquine was 33 ms. Nineteen out of 344 patients unnecessarily had their treatment prematurely discontinued or adjusted due to a prolonged QTc interval based on the computerised interpretation of the ECG.ConclusionChloroquine treatment in COVID-19 patients gradually increased the QTc interval. Due to a significant number of overestimated QTc intervals by computer analysis, it is advisable to measure the QTc interval manually before adjusting the dose or withdrawing this potentially beneficial medication.

Assessing the risk of seizures with chloroquine or hydroxychloroquine therapy for COVID-19 in persons with epilepsy

BackgroundThe goal of this systematic review is to assess the published literature for seizure risk with chloroquine or hydroxychloroquine therapy in persons with and without epilepsy. With the COVID-19 pandemic, there is a desperate need for treatment against the SARS CoV-2 virus. Chloroquine or hydroxychloroquine is one proposed medication that has received substantial public attention. However, the package insert states that these medications may provoke seizures in patients with epilepsy, and this has resulted in increased questions and anxiety in the epilepsy community. MethodsPubMed (1970 to March 27, 2020) and the Embase (1970 to March 27, 2020) were searched with the terms chloroquine or hydroxychloroquine and seizure or epilepsy, convulsions, or status epilepticus. Selected studies were reviewed, and the adverse drug reaction was classified. ResultsOnly eleven out of 31 studies were deemed eligible for systematic analysis. For chloroquine, eligible studies were- one prospective study(n = 109), two case series(n = 6), and six case reports. The dose of chloroquine ranged between 100−500 mg/day, except in one patient with a seizure, who was after taking 1000 mg. For hydroxychloroquine, there was one prospective observational study(n = 631) and one case report. The clinical trials failed to find any significant relation between seizures and chloroquine or hydroxychloroquine. ConclusionAlthough the package insert describes an increased risk of seizure, the systematic review highlights that such a statement is not supported by class I evidence. Clinicians, therefore, need to understand that data regarding this specific topic is limited to case series and case reports. There is no substantial evidence to suggest that these medications can increase seizure risk.

Clinical Implications of Chloroquine and Hydroxychloroquine Ototoxicity for COVID-19 Treatment: A Mini-Review

At this time of the COVID-19 pandemic, potentially effective treatments are currently under urgent investigation. Benefits of chloroquine and hydroxychloroquine for the treatment of COVID-19 infection have been proposed and clinical trials are underway. Chloroquine and hydroxychloroquine, typically used for the treatment of malaria and autoimmune diseases, have been considered for off-label use in several countries. In the literature, there are reports of ototoxic effects of the drugs causing damage to the inner ear structures, which then result in hearing loss, tinnitus, and/or imbalance. This mini-review represents a summary of the findings from a systematic search regarding ototoxicity of chloroquine and hydroxychloroquine in the published literature. The characteristics of sensorineural hearing loss and/or tinnitus after chloroquine or hydroxychloroquine treatment can be temporary but reports of persistent auditory and vestibular dysfunction exist. These are not frequent, but the impact can be substantial. Additionally, abnormal cochleovestibular development in the newborn was also reported after chloroquine treatment in pregnant women. The suggested dose of chloroquine for COVID-19 infection is considerably higher than the usual dosage for malaria treatment; therefore, it is plausible that the ototoxic effects will be greater. There are potential implications from this review for survivors of COVID-19 treated with chloroquine or hydroxychloroquine. Patient reports of hearing loss, tinnitus, or imbalance should be noted. Those with troublesome hearing loss, tinnitus and/or imbalance are encouraged to be referred for hearing evaluation and interventions once they are stable. Clinical trials of chloroquine or hydroxychloroquine should also consider including audiological monitoring in the protocol.

Chloroquine dosage regimens in patients with COVID-19: Safety risks and optimization using simulations

Currently no specific medicinal treatment exists against the new SARS-CoV2 and chloroquine is widely used, since it can decrease the length of hospital stay and improve the evolution of the associated COVID-19 pneumonia. However, several safety concerns have been raised from chloroquine use due to the lack of essential information regarding its dosing. The aim of this study is to provide a critical appraisal of the safety information regarding chloroquine treatment and to apply simulation techniques to unveil relationships between the observed serious adverse events and overdosing, as well as to propose optimized dosage regimens. The dose related adverse events of chloroquine are unveiled and maximum tolerated doses and concentration levels are quoted. Among others, treatment with chloroquine can lead to severe adverse effects like prolongation of the QT interval and cardiomyopathy. In case of chloroquine overdosing, conditions similar to those produced by SARS-CoV2, such as pulmonary oedema with respiratory insufficiency and circulatory collapse, can be observed. Co-administration of chloroquine with other drugs for the treatment of COVID-19 patients, like azithromycin, can further increase the risk of QT prolongation and cardiomyopathy. For elder patients there is a high risk for toxicity and dose reduction should be made. This study unveils the risks of some widely used dosing regimens and binds the observed serious adverse events with dosing. Based on simulations, safer alternative dosage regimens are proposed and recommendations regarding chloroquine dosing are made.