73 research outputs found

    Just Click Here : A Brief Glance at Absurd Electronic Contracts and the Law Failing to Protect Consumers

    Get PDF
    As e-commerce explodes around the world, consumers’ rights have been left behind. Before the completion of virtually every transaction on the Internet, the onus is placed on consumers to read and agree to an onslaught of terms and conditions. Often hidden in the middle of this extremely lengthy list of terms are massive exemption and limitation of liability clauses that deny consumers most if not all of their rights as “equal” trading partners. The common law principle that all onerous clauses in a contract need to be brought to the attention of the consumer for them to be binding seems to have been lost with the invention of the “click here to agree” button for signing online contracts. As the courts in Canada have not provided clear guidance on this issue thus far, other means must be pursued in order to protect consumers from the near-tyrannical control of unencumbered electronic standard form contracts in e-commerce. This paper will describe the principle of sufficiency of notice as it applies to paper contracts, and then contrast it with the newer jurisprudence that has refused to apply the principle to electronic contracts. The reasons for the refusal will be explored, followed by an examination of why the principle of sufficiency of notice needs to be applied and strengthened to respond to the increasingly onerous provisions hidden in electronic contracts. Finally, some other options for achieving the goal of consumer protection from hidden onerous clauses will be briefly explored. These other options include introducing stiffer consumer protection legislation domestically, the creation of international treaties, developing voluntary standards of contracting, and relying on Internet self-regulation

    Population Pharmacokinetic Properties of Piperaquine in Falciparum Malaria: An Individual Participant Data Meta-Analysis.

    Get PDF
    BACKGROUND: Artemisinin-based combination therapies (ACTs) are the mainstay of the current treatment of uncomplicated Plasmodium falciparum malaria, but ACT resistance is spreading across Southeast Asia. Dihydroartemisinin-piperaquine is one of the five ACTs currently recommended by the World Health Organization. Previous studies suggest that young children (<5 y) with malaria are under-dosed. This study utilised a population-based pharmacokinetic approach to optimise the antimalarial treatment regimen for piperaquine. METHODS AND FINDINGS: Published pharmacokinetic studies on piperaquine were identified through a systematic literature review of articles published between 1 January 1960 and 15 February 2013. Individual plasma piperaquine concentration-time data from 11 clinical studies (8,776 samples from 728 individuals) in adults and children with uncomplicated malaria and healthy volunteers were collated and standardised by the WorldWide Antimalarial Resistance Network. Data were pooled and analysed using nonlinear mixed-effects modelling. Piperaquine pharmacokinetics were described successfully by a three-compartment disposition model with flexible absorption. Body weight influenced clearance and volume parameters significantly, resulting in lower piperaquine exposures in small children (<25 kg) compared to larger children and adults (≥25 kg) after administration of the manufacturers' currently recommended dose regimens. Simulated median (interquartile range) day 7 plasma concentration was 29.4 (19.3-44.3) ng/ml in small children compared to 38.1 (25.8-56.3) ng/ml in larger children and adults, with the recommended dose regimen. The final model identified a mean (95% confidence interval) increase of 23.7% (15.8%-32.5%) in piperaquine bioavailability between each piperaquine dose occasion. The model also described an enzyme maturation function in very young children, resulting in 50% maturation at 0.575 (0.413-0.711) y of age. An evidence-based optimised dose regimen was constructed that would provide piperaquine exposures across all ages comparable to the exposure currently seen in a typical adult with standard treatment, without exceeding the concentration range observed with the manufacturers' recommended regimen. Limited data were available in infants and pregnant women with malaria as well as in healthy individuals. CONCLUSIONS: The derived population pharmacokinetic model was used to develop a revised dose regimen of dihydroartemisinin-piperaquine that is expected to provide equivalent piperaquine exposures safely in all patients, including in small children with malaria. Use of this dose regimen is expected to prolong the useful therapeutic life of dihydroartemisinin-piperaquine by increasing cure rates and thereby slowing resistance development. This work was part of the evidence that informed the World Health Organization technical guidelines development group in the development of the recently published treatment guidelines (2015)

    The Novel bis-1,2,4-Triazine MIPS-0004373 Demonstrates Rapid and Potent Activity against All Blood Stages of the Malaria Parasite

    Get PDF
    Novel bis-1,2,4-triazine compounds with potent in vitro activity against Plasmodium falciparum parasites were recently identified. The bis-1,2,4-triazines represent a unique antimalarial pharmacophore and are proposed to act by a novel but as-yet-unknown mechanism of action. This study investigated the activity of the bis-1,2,4-triazine MIPS-0004373 across the mammalian life cycle stages of the parasite and profiled the kinetics of activity against blood and transmission stage parasites in vitro and in vivo. MIPS-0004373 demonstrated rapid and potent activity against P. falciparum, with excellent in vitro activity against all asexual blood stages. Prolonged in vitro drug exposure failed to generate stable resistance de novo, suggesting a low propensity for the emergence of resistance. Excellent activity was observed against sexually committed ring stage parasites, but activity against mature gametocytes was limited to inhibiting male gametogenesis. Assessment of liver stage activity demonstrated good activity in an in vitro P. berghei model but no activity against Plasmodium cynomolgi hypnozoites or liver schizonts. The bis-1,2,4-triazine MIPS-0004373 efficiently cleared an established P. berghei infection in vivo, with efficacy similar to that of artesunate and chloroquine and a recrudescence profile comparable to that of chloroquine. This study demonstrates the suitability of bis-1,2,4-triazines for further development toward a novel treatment for acute malaria

    The risk of Plasmodium vivax parasitaemia after P. falciparum malaria: An individual patient data meta-analysis from the WorldWide Antimalarial Resistance Network.

    Get PDF
    BACKGROUND: There is a high risk of Plasmodium vivax parasitaemia following treatment of falciparum malaria. Our study aimed to quantify this risk and the associated determinants using an individual patient data meta-analysis in order to identify populations in which a policy of universal radical cure, combining artemisinin-based combination therapy (ACT) with a hypnozoitocidal antimalarial drug, would be beneficial. METHODS AND FINDINGS: A systematic review of Medline, Embase, Web of Science, and the Cochrane Database of Systematic Reviews identified efficacy studies of uncomplicated falciparum malaria treated with ACT that were undertaken in regions coendemic for P. vivax between 1 January 1960 and 5 January 2018. Data from eligible studies were pooled using standardised methodology. The risk of P. vivax parasitaemia at days 42 and 63 and associated risk factors were investigated by multivariable Cox regression analyses. Study quality was assessed using a tool developed by the Joanna Briggs Institute. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42018097400). In total, 42 studies enrolling 15,341 patients were included in the analysis, including 30 randomised controlled trials and 12 cohort studies. Overall, 14,146 (92.2%) patients had P. falciparum monoinfection and 1,195 (7.8%) mixed infection with P. falciparum and P. vivax. The median age was 17.0 years (interquartile range [IQR] = 9.0-29.0 years; range = 0-80 years), with 1,584 (10.3%) patients younger than 5 years. 2,711 (17.7%) patients were treated with artemether-lumefantrine (AL, 13 studies), 651 (4.2%) with artesunate-amodiaquine (AA, 6 studies), 7,340 (47.8%) with artesunate-mefloquine (AM, 25 studies), and 4,639 (30.2%) with dihydroartemisinin-piperaquine (DP, 16 studies). 14,537 patients (94.8%) were enrolled from the Asia-Pacific region, 684 (4.5%) from the Americas, and 120 (0.8%) from Africa. At day 42, the cumulative risk of vivax parasitaemia following treatment of P. falciparum was 31.1% (95% CI 28.9-33.4) after AL, 14.1% (95% CI 10.8-18.3) after AA, 7.4% (95% CI 6.7-8.1) after AM, and 4.5% (95% CI 3.9-5.3) after DP. By day 63, the risks had risen to 39.9% (95% CI 36.6-43.3), 42.4% (95% CI 34.7-51.2), 22.8% (95% CI 21.2-24.4), and 12.8% (95% CI 11.4-14.5), respectively. In multivariable analyses, the highest rate of P. vivax parasitaemia over 42 days of follow-up was in patients residing in areas of short relapse periodicity (adjusted hazard ratio [AHR] = 6.2, 95% CI 2.0-19.5; p = 0.002); patients treated with AL (AHR = 6.2, 95% CI 4.6-8.5; p < 0.001), AA (AHR = 2.3, 95% CI 1.4-3.7; p = 0.001), or AM (AHR = 1.4, 95% CI 1.0-1.9; p = 0.028) compared with DP; and patients who did not clear their initial parasitaemia within 2 days (AHR = 1.8, 95% CI 1.4-2.3; p < 0.001). The analysis was limited by heterogeneity between study populations and lack of data from very low transmission settings. Study quality was high. CONCLUSIONS: In this meta-analysis, we found a high risk of P. vivax parasitaemia after treatment of P. falciparum malaria that varied significantly between studies. These P. vivax infections are likely attributable to relapses that could be prevented with radical cure including a hypnozoitocidal agent; however, the benefits of such a novel strategy will vary considerably between geographical areas

    Baseline data of parasite clearance in patients with falciparum malaria treated with an artemisinin derivative: an individual patient data meta-analysis.

    Get PDF
    BACKGROUND: Artemisinin resistance in Plasmodium falciparum manifests as slow parasite clearance but this measure is also influenced by host immunity, initial parasite biomass and partner drug efficacy. This study collated data from clinical trials of artemisinin derivatives in falciparum malaria with frequent parasite counts to provide reference parasite clearance estimates stratified by location, treatment and time, to examine host factors affecting parasite clearance, and to assess the relationships between parasite clearance and risk of recrudescence during follow-up. METHODS: Data from 24 studies, conducted from 1996 to 2013, with frequent parasite counts were pooled. Parasite clearance half-life (PC1/2) was estimated using the WWARN Parasite Clearance Estimator. Random effects regression models accounting for study and site heterogeneity were used to explore factors affecting PC1/2 and risk of recrudescence within areas with reported delayed parasite clearance (western Cambodia, western Thailand after 2000, southern Vietnam, southern Myanmar) and in all other areas where parasite populations are artemisinin sensitive. RESULTS: PC1/2 was estimated in 6975 patients, 3288 of whom also had treatment outcomes evaluate d during 28-63 days follow-up, with 93 (2.8 %) PCR-confirmed recrudescences. In areas with artemisinin-sensitive parasites, the median PC1/2 following three-day artesunate treatment (4 mg/kg/day) ranged from 1.8 to 3.0 h and the proportion of patients with PC1/2 >5 h from 0 to 10 %. Artesunate doses of 4 mg/kg/day decreased PC1/2 by 8.1 % (95 % CI 3.2-12.6) compared to 2 mg/kg/day, except in populations with delayed parasite clearance. PC1/2 was longer in children and in patients with fever or anaemia at enrolment. Long PC1/2 (HR = 2.91, 95 % CI 1.95-4.34 for twofold increase, p < 0.001) and high initial parasitaemia (HR = 2.23, 95 % CI 1.44-3.45 for tenfold increase, p < 0.001) were associated independently with an increased risk of recrudescence. In western Cambodia, the region with the highest prevalence of artemisinin resistance, there was no evidence for increasing PC1/2 since 2007. CONCLUSIONS: Several factors affect PC1/2. As substantial heterogeneity in parasite clearance exists between locations, early detection of artemisinin resistance requires reference PC1/2 data. Studies with frequent parasite count measurements to characterize PC1/2 should be encouraged. In western Cambodia, where PC1/2 values are longest, there is no evidence for recent emergence of higher levels of artemisinin resistance

    Short Report: Tafenoquine for the treatment of recurrent Plasmodium Vivax Malaria

    No full text
    Tafenoquine was used to treat Plasmodium vivax malaria cases who had previously failed treatment with chloroquine and primaquine. Chloroquine was followed by a loading dose of tafenoquine (200 mg base/day for 3 days) and 200 mg a week was given for 8 weeks. One of 27 treated patients relapsed after 6 months of observation. A standard course of chloroquine administered with 8 weeks of tafenoquine may be more effective than chloroquine with primaquine (22.5 mg/day for 14 days) in preventing additional P. vivax relapses. Larger studies are required to optimize the combination, but our findings suggest that an extended use of tafenoquine may be required to prevent relapses of primaquine-tolerant strains of P. vivax malaria
    • …
    corecore