Quinacrine, a PLA2 inhibitor, alleviates LPS-induced acute kidney injury in rats: Involvement of TLR4/NF-κB/TNF α-mediated signaling.

Acute Kidney Injury (AKI) is a major factor in sepsis-related mortality and may occur due to lipopolysaccharide (LPS), an endotoxin produced by gram-negative bacteria that triggers a systemic acute inflammatory response. Quinacrine's (QC) renoprotective properties in sepsis and the underlying mechanism, however, are still not fully understood. This study was done to investigate the anti-inflammatory, antioxidative, and anti-apoptotic effects of QC, a phospholipase A2 (PLA2) inhibitor, against LPS-induced AKI. Rats were randomly divided into five groups: control group, QC30 group, LPS group, LPS+QC 10 group, and LPS+QC 30 group. The rats were administered intraperitoneally QC (10 and 30 mg/kg) for 3 days (once a day) prior to injection of LPS (3 mg/kg). Six hours after the LPS injection, the histopathological changes, oxidative stress, inflammation, and apoptosis in the collected kidney tissues were detected by hematoxylin and eosin staining, enzyme-linked immunosorbent assay (ELISA), real-time PCR (RT-PCR), and immunohistochemistry staining, respectively. QC pretreatment could successfully attenuate LPS-induced AKI, as evidenced by a decrease in tissue histopathological injury. Meanwhile, QC alleviated LPS-induced kidney oxidative stress; it reduced MDA levels and increased levels of SOD, CAT, GPX, and GSH. LPS-induced elevations in kidney TLR4, NF-κB, TNF-α, IL-1ß, IL-6, PLA2, caspase 3, and Bax contents were significantly attenuated in QC-treated groups. Our findings revealed a significant effect of QC: protecting against LPS-induced AKI through inhibition of PLA2 and decreasing inflammation, oxidative stress, and apoptosis. To treat LPS-induced AKI, QC may be an effective substance with an excellent protection profile.

Quinacrine Treatment of Nitroimidazole-Refractory Giardiasis.

BACKGROUND: Limited evidence exists on efficacy and tolerability of quinacrine for nitroimidazole-refractory giardiasis. METHODS: Nitroimidazole-refractory giardiasis cases, defined as microbiologically (microscopy and/or PCR) confirmed treatment failure after 2 courses, during 2008-2020, were retrospectively identified. RESULTS: Of 87 patients, 54 (62%) had visited India. Quinacrine was used in 54 (62%); 51 received monotherapy and 3 combined with metronidazole. Only 3 had positive stool samples with persisting symptoms after quinacrine treatment (94% parasitological efficacy) and all were cured after a second treatment. One (1.9%) had mild adverse effects recorded. CONCLUSIONS: Quinacrine is an effective treatment for nitroimidazole-refractory giardiasis with good tolerability.

Treatment strategies for nitroimidazole-refractory giardiasis: a systematic review.

RATIONALE FOR REVIEW: Giardiasis is one of the most common human protozoal infections worldwide. First-line therapy of giardiasis includes nitroimidazole antibiotics. However, treatment failure with nitroimidazoles is increasingly reported, with up to 45% of patients not responding to initial treatment. There is no clear consensus on the approach to the management of nitroimidazole-refractory giardiasis. This systematic review aims to summarize the literature on pharmacotherapy for nitroimidazole-refractory giardiasis. METHODS: We conducted a systematic review of the literature to determine the optimal management strategies for nitroimidazole-refractory giardiasis. We searched Pubmed/MEDLINE, Embase and Cochrane library using the following search terms 'Giardia' AND 'treatment failure' OR 'refractory giardia' OR 'resistant giardia' with date limits of 1 January 1970 to 30 June 2021. We included all reports on humans, which described clinical outcomes of individuals with treatment refractory giardiasis, including case series and case reports. A descriptive synthesis of the data was conducted with pooling of data for interventions. KEY FINDINGS: Included in this review were five prospective studies, three retrospective studies, seven case series and nine case reports. Across these reports, a wide heterogeneity of treatment regimens was employed, including retreatment with an alternative nitroimidazole, combination therapy with a nitroimidazole and another agent and monotherapy with non-nitroimidazole regimens, including quinacrine, paromomycin and nitazoxanide. Retreatment with a nitroimidazole was not an effective therapy for refractory giardiasis. However, treatment with a nitroimidazole in combination with albendazole had a cure rate of 66.9%. In the included studies, quinacrine monotherapy was administered to a total of 179 patients, with a clinical cure rate of 88.8%. Overall, quinacrine was fairly well tolerated. CONCLUSIONS: Reports on the treatment of nitroimidazole-refractory giardiasis demonstrate a heterogeneous approach to treatment. Of these, quinacrine appeared to be highly effective, though more data on its safety are needed.

Efficacy and Tolerability of Quinacrine Monotherapy and Albendazole Plus Chloroquine Combination Therapy in Nitroimidazole-Refractory Giardiasis: A TropNet Study.

BACKGROUND: Giardiasis failing nitroimidazole first-line treatment is an emerging problem in returning European travelers. We present data on the efficacy and tolerability of 2 second-line treatment regimens. METHODS: This prospective, open-label, multicenter study assessed the efficacy and tolerability of quinacrine monotherapy (100 mg 3 times per day for 5 days) and albendazole plus chloroquine combination therapy (400 mg twice daily plus 155 mg twice daily for 5 days) in nitroimidazole-refractory giardiasis. The defined end points were the clinical outcome, assessed at week 5 after treatment and the parasitological outcome, assessed using microscopy of 2 stool samples, ≥2 to ≤5 weeks after treatment. RESULTS: A total of 106 patients were included in the study. Quinacrine achieved clinical and parasitological cure in 81% (59/73) and 100% (56/56), respectively. Albendazole plus chloroquine achieved clinical and parasitological cure in 36% (12/33) and 48% (12/25), respectively. All patients (9/9) who clinically and parasitologically failed albendazole plus chloroquine treatment and opted for retreatment with quinacrine achieved clinical cure. Mild to moderate treatment-related adverse events were reported by 45% and 30% of patients treated with quinacrine and albendazole plus chloroquine, respectively. One patient treated with quinacrine developed severe neuropsychiatric side effects. The majority of nitroimidazole-refractory Giardia infections (57%) were acquired in India. CONCLUSIONS: Quinacrine was a highly effective treatment in nitroimidazole-refractory giardiasis, but patients should be cautioned on the low risk of severe neuropsychiatric adverse event. Albendazole plus chloroquine had a low cure rate in nitroimidazole-refractory giardiasis. Nitroimidazole-refractory giardiasis was primarily seen in travelers returning from India.

Quinacrine as a potential treatment for COVID-19 virus infection.

A novel coronavirus named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a current outbreak of infection termed Coronavirus Disease 2019 (COVID-19) by the World Health Organization (WHO). COVID-19 is currently a global pandemic that may cause close to half a billion deaths around the world. Until now, there is no effective treatment for COVID-19. Quinacrine (Qx) has been used since the 1930s as preventive antimalarial compound. It is a recognized small molecule inhibitor of RNA virus replication, with known anti-prion activity, and identified as a potent Ebola virus inhibitor both in vitro and in vivo. Recently, Qx has showed anti-SARS-CoV-2 activity. Herein, we review the potential mechanisms associated with quinacrine as an antiviral compound.

First-in-Human Phase 1b Trial of Quinacrine Plus Capecitabine in Patients With Refractory Metastatic Colorectal Cancer.

BACKGROUND: Quinacrine plus a fluoropyrimidine has in vivo efficacy against metastatic colorectal cancer (mCRC). This phase 1b trial evaluated the combination of quinacrine plus capecitabine in patients with treatment-refractory mCRC. PATIENTS AND METHODS: Using a modified Simon accelerated titration design, adults with treatment-refractory mCRC were treated with capecitabine 1000 mg/m2 twice daily for 14/21-day cycle, and escalating doses of quinacrine 100 mg daily, 100 mg twice daily, and 200 mg twice daily for 21 days. The primary endpoint was identifying the maximum tolerated dose, determining tolerability and safety. In an expansion cohort, it was overall response rate and time to tumor progression (TTP). RESULTS: Ten patients (median age of 60 years) were treated in phase 1b. The first 2 quinacrine dosing levels were well tolerated. Dose-limiting toxicities were seen in 3 patients treated with quinacrine 200 mg twice daily. Five additional patients tolerated quinacrine 100 mg twice daily without further dose-limiting toxicities, thus establishing the maximum tolerated dose. Seven additional expansion-cohort patients enrolled onto the study before quinacrine manufacturing ceased within the United States. Five patients experienced stable disease, 1 partial response, and 10 disease progression. Median TTP overall was 2.12 months and median overall survival 5.22 months for the 17 patients. CONCLUSION: Capecitabine and quinacrine can be safely administered at the maximum tolerated dose of capecitabine 1000 mg/m2 by mouth twice daily on days 1-14 and quinacrine 100 mg by mouth twice daily on days 1-21 of a 21-day cycle in mCRC patients. Although the expansion study was halted early, TTP was in line with other studies of refractory mCRC, suggesting activity of this regimen in heavily pretreated patients.

A Case of Quinacrine-induced Psychosis: Case Report.

BACKGROUND: Quinacrine is an older antimalarial drug that remains in use for a variety of illnesses including treatment-resistant giardiasis. CASE PRESENTATION: We report a patient with no prior psychiatric history who developed mild, prodromal psychiatric symptoms when treated with quinacrine for treatment-resistant giardiasis. Symptoms resolved when the drug was stopped, recurred with greater severity (requiring involuntary psychiatric hospitalization) when restarted and promptly resolved again when the drug was finally stopped. CONCLUSION: Although quinacrine remains in use today, providers may be unaware of its potential for serious neuropsychiatric toxicity.

Glucocorticoids and antimalarials in systemic lupus erythematosus: an update and future directions.

PURPOSE OF REVIEW: The purpose of this review is highlighting the most recent evidence on the clinical efficacy and toxicity of glucocorticoids and antimalarials in systemic lupus erythematosus (SLE) and provide recommendations on their current use. RECENT FINDINGS: Glucocorticoid toxicity is well known. Recent data confirm the increased risk of infection and damage accrual. An observational study form Hong Kong has seen increased mortality among users of high-dose prednisone regimes. Several studies support the efficacy of medium-low doses and methyl-prednisolone pulses in lupus patients, both with and without nephritis.New data confirm the effects of antimalarials in preventing SLE activity, damage and infections, and in decreasing mortality. New screening recommendations for hydroxychloroquine maculopathy have been recently published. Combining mepacrine and hydroxychloroquine in patients with refractory cutaneous and/or articular lupus activity has proved highly effective. SUMMARY: Universal therapy with hydroxychloroquine should be aimed to patients with SLE without contraindications. Doses greater than 4 mg/kg/day should be avoided and regular eye screening warranted to minimize the risk of macular toxicity. Every effort should be made to reduce the dose of oral glucocorticoids. In moderate-severe flares, pulse methyl-prednisolone are more effective and much less toxic than increasing the oral doses of prednisone.

Long-term risk of hysterectomy and ectopic pregnancy among Vietnamese women using the quinacrine hydrochloride pellet system vs. intrauterine devices or tubal ligation for contraception.

OBJECTIVES: Determine the long-term risk of hysterectomy and ectopic pregnancy in women using the quinacrine hydrochloride pellet system of permanent contraception (QS) relative to the comparable risk in women using Copper T intrauterine device (IUD) or tubal ligation surgery (TL) for long-term or permanent contraception. METHODS: This was a retrospective cohort study, conducted in the Northern Vietnamese provinces of Ha Nam, Nam Dinh, Ninh Binh and Thai Binh. Women who had their first QS procedure, last IUD insertion or TL between 1989 and 1996 were interviewed regarding post-procedure health outcomes approximately 16 years post exposure. RESULTS: A 95% response rate resulted in 21,040 completed interviews. Overall incidence rates were low for both outcomes (91/100,000 women years of follow-up and 22/100,000 women years of follow-up for hysterectomy and ectopic pregnancy, respectively). After accounting for variations in baseline characteristics between women choosing QS vs. the other two contraceptive methods, no significant excess hazard of either hysterectomy or ectopic pregnancy was associated with QS. CONCLUSIONS: No significant excess long-term risk of hysterectomy or ectopic pregnancy was found among a large group of women using QS vs. IUD or TL for contraception after an average 16 years of follow-up.

Combined mepacrine-hydroxychloroquine treatment in patients with systemic lupus erythematosus and refractory cutaneous and articular activity.

Aim The aim of this study was to evaluate the clinical response to combined therapy with hydroxychloroquine and mepacrine in patients with systemic lupus erythematosus and refractory joint and/or skin disease. Methods Mepacrine was added to 46 systemic lupus erythematosus patients unresponsive to treatment with the following drug combinations: hydroxychloroquine + prednisone + immunosuppressive drugs ( n = 24), hydroxychloroquine + prednisone ( n = 16), hydroxychloroquine + prednisone + retinoids ( n = 2), hydroxychloroquine alone ( n = 1), hydroxychloroquine + one immunosuppressive drug ( n = 1), hydroxychloroquine + prednisone + one immunosuppressive drug + belimumab ( n = 1) or hydroxychloroquine + prednisone + belimumab ( n = 1). The outcome variable was the clinical response, either complete or partial, based on clinical judgement. The Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) and the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score were additionally used. Results A total of 91% patients showed complete/partial response, with similar rates among those with joint or skin disease. In patients with cutaneous activity, a statistically significant decrease in the CLASI was seen. There also was a statistically significant decrease in the SLEDAI. The mean daily dose of prednisone decreased from 5.8 to 3.4 mg/d ( p = 0.001). Prednisone could be discontinued in 20% of patients. No serious adverse events were seen. Smoking was the only predictor of complete response. Conclusion In the setting of refractory skin and/or joint disease, the addition of mepacrine to previous therapy including hydroxychloroquine was safe and effective in reducing disease activity and decreasing prednisone doses. The fact that smokers responded better opens the door to further studying the combination of mepacrine-hydroxychloroquine as a first-line therapy in such patients.

Phase I study of the combination of quinacrine and erlotinib in patients with locally advanced or metastatic non small cell lung cancer.

Introduction Preclinical data suggest quinacrine acts as an inhibitor of FACT (facilitates chromatin transcription) complex, which may play a role in TKI (tyrosine kinase inhibitor) resistance. The aim of this Phase I study was to study the safety and assess the maximum tolerated dose of quinacrine in combination with erlotinib in non small cell lung cancer (NSCLC). Methods This was a phase I study with standard 3 + 3 dose escalation design with the primary aim of determining the maximum tolerated dose. Two of 3 patients enrolled at dose level 1 experienced dose limiting toxicity (DLT). The next 6 patients were enrolled at dose level - 1 and none of these 6 patients experienced DLT. The dose of 50 mg of quinacrine every other day with 150 mg of erlotinib was established as the maximum tolerated and the recommended phase II dose. One of 3 patients treated at dose level 1 had stable disease. One of 6 patients treated at dose level - 1 had partial response for 6 months, the rest had progressive disease at the time of first assessment. Conclusion Combination of quinacrine and erlotinib was well tolerated but showed limited efficacy in advanced NSCLC.

The Use of Quinacrine in Nitroimidazole-resistant Giardia Duodenalis: An Old Drug for an Emerging Problem.

Background: There is little evidence regarding the management of refractory giardiasis after treatment with nitroimidazoles. This study estimates the proportion of persistent giardiasis in 3 hospitals in Barcelona, describes associated risk factors and genotype, and evaluates the efficacy rate of quinacrine in those with persistent giardiasis. Methods: A clinical, prospective, observational study was conducted in patients with giardiasis treated with nitroimidazoles. Those with persistent giardiasis were provided quinacrine. Molecular characterization of Giardia isolates was performed by polymerase chain reaction amplification of a fragment of tpi and bg genes. Results: Seventy-seven patients were recruited and treated with nitroimidazoles, and in 14 of 71 (20%) of patients followed up, Giardia persisted. Refractory giardiasis was associated with malaise (P = .007) and anorexia (P = .02), with previous giardiasis (P = .03), and with previous antibiotic (P = .02) or antiparasitic(P = .04) use. Quinacrine had an effectiveness rate of 100% in refractory giardiasis (n = 13; 95% confidence interval = 75-100). Molecular characterization showed that 17 (25%) Giardia isolates belonged to assemblage A, and 31 (43%) belonged to assemblage B. In refractory giardiasis, assemblage A and B were found responsible in 4 and 6 cases, respectively. Conclusions: Almost 20% of patients presented persistent giardiasis, belonging to both assemblages A and B, after nitroimidazole. Short course of quinacrine was effective in treating refractory cases. Further controlled studies should evaluate its efficacy and safety.

Long-term risk of reproductive cancer among Vietnamese women using the quinacrine hydrochloride pellet system vs. intrauterine devices or tubal ligation for contraception.

OBJECTIVES: To determine the long-term risk of reproductive tract cancer in women using the quinacrine hydrochloride pellet system of permanent contraception (QS) relative to the comparable risk in women using Copper T intrauterine device (IUD) or tubal ligation surgery (TL) for long-term or permanent contraception. METHODS: This was a retrospective cohort study, conducted in the Northern Vietnamese provinces of Ha Nam, Nam Dinh, Ninh Binh and Thai Binh. Women who had their first QS procedure, last IUD insertion or TL between 1989 and 1996 were interviewed regarding post-procedure health outcomes, particularly reproductive tract cancers. RESULTS: A 95% response rate resulted in 21,040 completed interviews. Reproductive cancer incidence rates were very low (5.77/100,000 women years of follow-up time; 95%CI = 3.72-8.94). No significant excess hazard of reproductive tract cancer was associated with QS. CONCLUSIONS: No significant excess long-term risk of reproductive tract cancer was found after an average 16 years of follow-up among a large group of women using QS vs. IUD/TL for contraception.

Quinacrine sterilization (QS): time for reconsideration.

Dr. Jaime Zipper, the Chilean inventor of the quinacrine method of nonsurgical permanent contraception, was aware that when chest surgeons injected quinacrine into the pleural cavity to treat and prevent reoccurrence of pleural effusion, it resulted in the formation of fibrous adhesions between the lung and costal pleura. Zipper thought that a similar scarring effect could occur in the fallopian tubes if quinacrine was instilled into the uterine cavity. A series of refinements of the methodology culminated in the use of a modified Copper T intrauterine device inserter tube as a delivery system to introduce seven quinacrine pellets into the uterus. This approach with quinacrine sterilization (QS) was introduced into clinical practice in several countries, and a national clinical trial of over 50,000 women was conducted in Vietnam. However, in 1993, the World Health Organization raised concerns that quinacrine might be carcinogenic. This resulted in abandonment of QS in Vietnam and other countries. Subsequent epidemiologic data from extensive human studies do not support an increase in cancer risk. This paper reviews the history, limitations and clinical potential of QS.

A nonsurgical permanent contraception stakeholder advisory committee: FHI 360's experience.

As part of its research program on nonsurgical permanent contraception, FHI 360, a nonprofit human development organization, created a stakeholder advisory committee to help address the controversy surrounding quinacrine. This committee contributed to FHI 360's research agenda, liaised with other stakeholders and provided input on key decisions. This report summarizes the process for establishing the committee, delineates the successes and challenges that arose and specifies recommendations for other organizations considering stakeholder collaboration.