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Drugs in R&D Dec 2017Approximately a third of the population worldwide is chronically infected with Toxoplasma gondii. Pyrimethamine-based regimens are recommended for the treatment of... (Review)
Review
INTRODUCTION
Approximately a third of the population worldwide is chronically infected with Toxoplasma gondii. Pyrimethamine-based regimens are recommended for the treatment of toxoplasmosis.
OBJECTIVE
The aim was to evaluate the safety profile of pyrimethamine-based treatment for the three main Toxoplasma manifestations: toxoplasmic encephalitis (TE), ocular toxoplasmosis, and congenital toxoplasmosis.
METHODS
PubMed, Cochrane Library, and Google Scholar databases were searched through August 1, 2016. Randomized, observational, prospective/retrospective, and cohort studies were eligible. Thirty-one studies were included with a total of 2975 patients. Of these, 13 were in congenital toxoplasmosis (n = 929), 11 in ocular toxoplasmosis (n = 1284), and seven in TE (n = 687). Across manifestations, adverse event (AE)-related treatment discontinuation and/or change in therapy involved ≤37% of patients and occurred in >55% of studies: 100% for ocular toxoplasmosis, 57.1% for TE, and 61.5% for congenital toxoplasmosis. The most commonly observed AEs were bone marrow suppression, dermatologic, and gastrointestinal (GI). The prevalence of bone marrow suppression-related AEs was ≤50% in congenital toxoplasmosis, ≤42.7% in TE, and ≤9.0% in ocular toxoplasmosis. The frequency of GI and dermatologic AEs were ≤100 and ≤11.1%, respectively, for ocular toxoplasmosis, ≤10.7 and ≤17.9% for TE, and ≤10.8 and ≤2.1% for congenital toxoplasmosis. Steven-Johnson syndrome was reported in two patients with ocular toxoplasmosis and one with TE.
CONCLUSION
The AE profile associated with pyrimethamine-based treatments differed by each manifestation of toxoplasmosis and within a given manifestation. Hematologic AEs occurred across all manifestations indicating the importance of monitoring the blood of patients administered pyrimethamine-based regimens.
Topics: Drug-Related Side Effects and Adverse Reactions; Humans; Infectious Encephalitis; Pyrimethamine; Toxoplasmosis, Cerebral; Toxoplasmosis, Congenital; Toxoplasmosis, Ocular
PubMed: 28879584
DOI: 10.1007/s40268-017-0206-8 -
CPT: Pharmacometrics & Systems... Jul 2017Sulfadoxine/pyrimethamine is recommended for intermittent preventative treatment of malaria during pregnancy. Data from 98 women during pregnancy and 77 after delivery... (Clinical Trial)
Clinical Trial
Sulfadoxine/pyrimethamine is recommended for intermittent preventative treatment of malaria during pregnancy. Data from 98 women during pregnancy and 77 after delivery in four African countries were analyzed using nonlinear mixed-effects modeling to characterize the effects of pregnancy, postpartum duration, and other covariates such as body weight and hematocrit on sulfadoxine/pyrimethamine pharmacokinetic properties. During pregnancy, clearance increased 3-fold for sulfadoxine but decreased by 18% for pyrimethamine. Postpartum sulfadoxine clearance decreased gradually over 13 weeks. This finding, together with hematocrit-based scaling of plasma to whole-blood concentrations and allometric scaling of pharmacokinetics parameters with body weight, enabled site-specific differences in the pharmacokinetic profiles to be reduced significantly but not eliminated. Further research is necessary to explain residual site-specific differences and elucidate whether dose-optimization, to address the 3-fold increase in clearance of sulfadoxine in pregnant women, is necessary, viable, and safe with the current fixed dose combination of sulfadoxine/pyrimethamine.
Topics: Adult; Africa; Antimalarials; Drug Combinations; Female; Humans; Malaria; Models, Biological; Postpartum Period; Pregnancy; Pyrimethamine; Sulfadoxine; Young Adult
PubMed: 28597978
DOI: 10.1002/psp4.12181 -
Trends in Parasitology Oct 2013Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps have rendered sulfadoxine-pyrimethamine (SP) ineffective for malaria treatment in most regions of the... (Review)
Review
Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps have rendered sulfadoxine-pyrimethamine (SP) ineffective for malaria treatment in most regions of the world. Yet, SP is efficacious as intermittent preventive therapy in pregnant women (IPTp) and infants (IPTi) and as seasonal malaria control in children (SMC). SP-IPTp is being widely implemented in sub-Saharan Africa. SP-IPTi is recommended where the prevalence of SP-resistant malaria parasites is low, whereas SMC is recommended for areas of intense seasonal malaria transmission. The continuing success of these interventions depends largely on the prevalence of Pfdhfr and Pfdhps resistance mutations in the target population. Here we review the relationship between resistance mutations and SP-IPT within target populations in the context of monitoring and informing implementation of this intervention.
Topics: Antimalarials; Drug Combinations; Drug Resistance; Humans; Malaria, Falciparum; Mutation; Plasmodium falciparum; Pyrimethamine; Sulfadoxine
PubMed: 23948432
DOI: 10.1016/j.pt.2013.07.008 -
Science Advances Mar 2023Reactivation of the latent HIV-1 reservoir is a first step toward triggering reservoir decay. Here, we investigated the impact of the BAF complex inhibitor pyrimethamine... (Randomized Controlled Trial)
Randomized Controlled Trial
Reactivation of the latent HIV-1 reservoir is a first step toward triggering reservoir decay. Here, we investigated the impact of the BAF complex inhibitor pyrimethamine on the reservoir of people living with HIV-1 (PLWH). Twenty-eight PLWH on suppressive antiretroviral therapy were randomized (1:1:1:1 ratio) to receive pyrimethamine, valproic acid, both, or no intervention for 14 days. The primary end point was change in cell-associated unspliced (CA US) HIV-1 RNA at days 0 and 14. We observed a rapid, modest, and significant increase in (CA US) HIV-1 RNA in response to pyrimethamine exposure, which persisted throughout treatment and follow-up. Valproic acid treatment alone did not increase (CA US) HIV-1 RNA or augment the effect of pyrimethamine. Pyrimethamine treatment did not result in a reduction in the size of the inducible reservoir. These data demonstrate that the licensed drug pyrimethamine can be repurposed as a BAF complex inhibitor to reverse HIV-1 latency in vivo in PLWH, substantiating its potential advancement in clinical studies.
Topics: Humans; CD4-Positive T-Lymphocytes; HIV Infections; HIV-1; Pyrimethamine; RNA; Valproic Acid; Virus Activation; Virus Latency
PubMed: 36921041
DOI: 10.1126/sciadv.ade6675 -
Frontiers in Immunology 2023In this review, we discuss a variety of immune modulating approaches that could be used to counteract tissue-damaging viral immunoinflammatory lesions which typify many... (Review)
Review
In this review, we discuss a variety of immune modulating approaches that could be used to counteract tissue-damaging viral immunoinflammatory lesions which typify many chronic viral infections. We make the point that in several viral infections the lesions can be largely the result of one or more aspects of the host response mediating the cell and tissue damage rather than the virus itself being directly responsible. However, within the reactive inflammatory lesions along with the pro-inflammatory participants there are also other aspects of the host response that may be acting to constrain the activity of the damaging components and are contributing to resolution. This scenario should provide the prospect of rebalancing the contributions of different host responses and hence diminish or even fully control the virus-induced lesions. We identify several aspects of the host reactions that influence the pattern of immune responsiveness and describe approaches that have been used successfully, mainly in model systems, to modulate the activity of damaging participants and which has led to lesion control. We emphasize examples where such therapies are, or could be, translated for practical use in the clinic to control inflammatory lesions caused by viral infections.
Topics: Humans; Models, Biological; Pyrimethamine; Sulfadiazine
PubMed: 37671156
DOI: 10.3389/fimmu.2023.1257192 -
The American Journal of Tropical... Apr 2023Maternal malaria and infections during pregnancy are risk factors for fetal growth restriction. We assessed the impact of preventive treatment in pregnancy on maternal... (Randomized Controlled Trial)
Randomized Controlled Trial
Maternal malaria and infections during pregnancy are risk factors for fetal growth restriction. We assessed the impact of preventive treatment in pregnancy on maternal malaria and fetal growth. Between 2003 and 2006, we enrolled 1,320 pregnant Malawian women, 14-26 gestation weeks, in a randomized trial and treated them with two doses of sulfadoxine-pyrimethamine (SP, control) at enrollment and between 28-34 gestation weeks; with monthly SP from enrollment until 37 gestation weeks; or with monthly SP and azithromycin twice, at enrollment and between 28 and 34 gestation weeks (AZI-SP). Participants were seen at 4-week intervals until 36 completed gestation weeks and weekly thereafter. At each visit, we collected dried blood spots for real-time polymerase chain reaction diagnosing of malaria parasitemia and, in a random subgroup of 341 women, we measured fetal biparietal diameter and femur length with ultrasound. For the monthly SP versus the control group, the odds ratios (OR) (95% CI) of malaria parasitemia during the second, third, and both trimesters combined were 0.79 (0.46-1.37), 0.58 (0.37-0.92), and 0.64 (0.42-0.98), respectively. The corresponding ORs for the AZI-SP versus control group were 0.47 (0.26-0.84), 0.51 (0.32-0.81), and 0.50 (0.32-0.76), respectively. Differences between the AZI-SP and the monthly SP groups were not statistically significant. The interventions did not affect fetal biparietal diameter and femur length growth velocity. The results suggest that preventive maternal treatment with monthly SP reduced malaria parasitemia during pregnancy in Malawi and that the addition of azithromycin did not provide much additional antimalarial effect.
Topics: Female; Pregnancy; Humans; Azithromycin; Parasitemia; Pregnancy Complications, Parasitic; Pyrimethamine; Malaria; Antimalarials; Drug Combinations; Fetal Development
PubMed: 36780896
DOI: 10.4269/ajtmh.22-0496 -
Molecules (Basel, Switzerland) Feb 2020In this era of precision medicine, insights into the resistance mechanism of drugs are integral for the development of potent therapeutics. Here, we sought to understand...
In this era of precision medicine, insights into the resistance mechanism of drugs are integral for the development of potent therapeutics. Here, we sought to understand the contribution of four point mutations (N51I, C59R, S108N, and I164L) within the active site of the malaria parasite enzyme dihydrofolate reductase (DHFR) towards the resistance of the antimalarial drug pyrimethamine. Homology modeling was used to obtain full-length models of wild type (WT) and mutant DHFR. Molecular docking was employed to dock pyrimethamine onto the generated structures. Subsequent all-atom molecular dynamics (MD) simulations and binding free-energy computations highlighted that pyrimethamine's stability and affinity inversely relates to the number of mutations within its binding site and, hence, resistance severity. Generally, mutations led to reduced binding affinity to pyrimethamine and increased conformational plasticity of DHFR. Next, dynamic residue network analysis (DRN) was applied to determine the impact of mutations and pyrimethamine binding on communication dispositions of DHFR residues. DRN revealed residues with distinctive communication profiles, distinguishing WT from drug-resistant mutants as well as pyrimethamine-bound from pyrimethamine-free models. Our results provide a new perspective on the understanding of mutation-induced drug resistance.
Topics: Amino Acids; Catalytic Domain; Drug Resistance; Ligands; Molecular Dynamics Simulation; Mutation; Plasmodium falciparum; Protein Domains; Pyrimethamine; Tetrahydrofolate Dehydrogenase; Thermodynamics
PubMed: 32085470
DOI: 10.3390/molecules25040904 -
Antimicrobial Agents and Chemotherapy Jul 1994The safety and pharmacokinetics of weekly dapsone and weekly dapsone plus pyrimethamine were examined in adult patients with human immunodeficiency virus infection who... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
The safety and pharmacokinetics of weekly dapsone and weekly dapsone plus pyrimethamine were examined in adult patients with human immunodeficiency virus infection who were at risk for pneumocystis pneumonia because of a prior episode or a CD4+ T-cell count less than 250 cells per mm3. Groups of patients received 100, 200, and 300 mg of dapsone as a single weekly dose. The maximum tolerated dose of weekly dapsone was established as 200 mg per week in patients receiving at least 500 mg of zidovudine concomitantly. This dose of dapsone was then found to be well tolerated when combined with pyrimethamine at 25 mg. Further patients were randomized to dapsone at 200 mg or dapsone at 200 mg plus pyrimethamine at 25 mg once weekly. Twenty-six patients each were followed for a median of 33 weeks on dapsone alone and 45 weeks on the combination. Seven patients in each group withdrew because of toxicity. Five patients receiving dapsone developed documented pneumocystis pneumonia, while four and two patients receiving dapsone plus pyrimethamine developed documented and presumptive pneumocystis pneumonia, respectively. To evaluate the tolerability of a higher dose of pyrimethamine, 11 patients had their regimen changed to dapsone at 200 mg plus pyrimethamine at 75 mg, which was well tolerated by 10 of the patients for a median period of 11 weeks. The pharmacokinetics of dapsone and pyrimethamine were examined by using a population pharmacokinetic model. Decreases in the apparent volume of the peripheral compartment were observed when multiple-dose regimens of dapsone were compared with single-dose dapsone and when multiple-dose regimens of dapsone with pyrimethamine were compared with multiple-dose dapsone alone. When administered weekly, dapsone at 200 mg and dapsone at 200 mg with pyrimethamine at 25 mg are both well-tolerated regimens. This preliminary study suggests that the efficacy of these regimens in preventing pneumocystis pneumonia, however, may be less than that of trimethoprim-sulfamethoxazole.
Topics: AIDS-Related Opportunistic Infections; Adult; Biological Availability; Chromatography, High Pressure Liquid; Dapsone; Drug Therapy, Combination; Female; Follow-Up Studies; Humans; Male; Middle Aged; Pneumonia, Pneumocystis; Pyrimethamine
PubMed: 7979291
DOI: 10.1128/AAC.38.7.1580 -
Lancet (London, England) Oct 2009Intermittent preventive treatment (IPT) is a promising strategy for malaria control in infants. We undertook a pooled analysis of the safety and efficacy of IPT in... (Meta-Analysis)
Meta-Analysis Review
Efficacy and safety of intermittent preventive treatment with sulfadoxine-pyrimethamine for malaria in African infants: a pooled analysis of six randomised, placebo-controlled trials.
BACKGROUND
Intermittent preventive treatment (IPT) is a promising strategy for malaria control in infants. We undertook a pooled analysis of the safety and efficacy of IPT in infants (IPTi) with sulfadoxine-pyrimethamine in Africa.
METHODS
We pooled data from six double-blind, randomised, placebo-controlled trials (undertaken one each in Tanzania, Mozambique, and Gabon, and three in Ghana) that assessed the efficacy of IPTi with sulfadoxine-pyrimethamine. In all trials, IPTi or placebo was given to infants at the time of routine vaccinations delivered by WHO's Expanded Program on Immunization. Data from the trials for incidence of clinical malaria, risk of anaemia (packed-cell volume <25% or haemoglobin <80 g/L), and incidence of hospital admissions and adverse events in infants up to 12 months of age were reanalysed by use of standard outcome definitions and time periods. Analysis was by modified intention to treat, including all infants who received at least one dose of IPTi or placebo.
FINDINGS
The six trials provided data for 7930 infants (IPTi, n=3958; placebo, n=3972). IPTi had a protective efficacy of 30.3% (95% CI 19.8-39.4, p<0.0001) against clinical malaria, 21.3% (8.2-32.5, p=0.002) against the risk of anaemia, 38.1% (12.5-56.2, p=0.007) against hospital admissions associated with malaria parasitaemia, and 22.9% (10.0-34.0, p=0.001) against all-cause hospital admissions. There were 56 deaths in the IPTi group compared with 53 in the placebo group (rate ratio 1.05, 95% CI 0.72-1.54, p=0.79). One death, judged as possibly related to IPTi because it occurred 19 days after a treatment dose, was subsequently attributed to probable sepsis. Four of 676 non-fatal hospital admissions in the IPTi group were deemed related to study treatment compared with five of 860 in the placebo group. None of three serious dermatological adverse events in the IPTi group were judged related to study treatment compared with one of 13 in the placebo group.
INTERPRETATION
IPTi with sulfadoxine-pyrimethamine was safe and efficacious across a range of malaria transmission settings, suggesting that this intervention is a useful contribution to malaria control.
FUNDING
Bill & Melinda Gates Foundation.
Topics: Africa; Anemia; Antimalarials; Double-Blind Method; Drug Administration Schedule; Drug Combinations; Follow-Up Studies; Humans; Immunization Schedule; Incidence; Infant; Infant Mortality; Malaria, Falciparum; Patient Admission; Pyrimethamine; Randomized Controlled Trials as Topic; Regression Analysis; Research Design; Risk Factors; Safety; Sulfadoxine; Treatment Outcome
PubMed: 19765816
DOI: 10.1016/S0140-6736(09)61258-7 -
Frontiers in Immunology 2022infects one-third of the world population. For decades, it has been considered a silent lifelong infection. However, chronically -infected persons may present...
Sulfadiazine Plus Pyrimethamine Therapy Reversed Multiple Behavioral and Neurocognitive Changes in Long-Term Chronic Toxoplasmosis by Reducing Brain Cyst Load and Inflammation-Related Alterations.
infects one-third of the world population. For decades, it has been considered a silent lifelong infection. However, chronically -infected persons may present psychiatric and neurocognitive changes as anxiety, depression, and memory loss. In a model of long-term chronic infection, behavioral alterations parallel neuroinflammation and systemic high cytokine levels, and may reflect brain cyst load. Recent findings support that in chronic infection an active parasite-host interplay involves an immune-mediated control of tissue cysts. Here, we tested the idea that etiological treatment in chronic phase may add advantage to intrinsic immune-mediated cyst control and impact behavioral changes. Thus, we combined sulfadiazine-plus-pyrimethamine (S+P), the first-choice therapy for toxoplasmosis, to study the association of brain cyst load and biological processes related to the immune response (neuroinflammation, blood-brain barrier -BBB- disruption and serum cytokine levels), with behavioral and neurocognitive changes of long-term chronic infection. Female C57BL/6 mice (H-2) were infected (5 cysts, ME-49 strain) and treated with S+P from 30 to 60 days postinfection (dpi), compared with vehicle (Veh)-treated and noninfected controls. At endpoints (pre-therapy, 30 dpi; S+P therapy, 60 dpi; after ceased therapy, 90 dpi), independent groups were subjected to behavioral tests, and brain tissues and sera were collected. Multiple behavioral and neurocognitive changes were detected in the early (30 dpi) and long-term (60 and 90 dpi) chronic infection. S+P therapy resolved locomotor alterations, anxiety, and depressive-like behavior, partially or transiently ameliorated hyperactivity and habituation memory loss. Analysis after therapy cessation showed that S+P therapy reduced the number of stimuli required for aversive memory consolidation. S+P therapy resulted in reduced brain cyst load, neuroinflammation and BBB disruption, and lowered systemic Th1-cytokine levels. Correlation analysis revealed association between IFNγ, TNF and MCP-1/CCL2 serum levels, brain cyst load and behavioral and neurocognitive alterations. Moreover, principal-component analysis (PCA-2D and 3D projections) highlighted distinction between clusters (noninfected; Veh-treated and S+P-treated infected). Thus, our data suggest that S+P therapy added gain to intrinsic brain cyst control and, direct or indirectly, ameliorated inflammation-related alterations, traits associated with behavioral and neurocognitive alterations.
Topics: Animals; Brain; Cytokines; Female; Inflammation; Memory Disorders; Mice; Mice, Inbred C57BL; Pyrimethamine; Sulfadiazine; Toxoplasmosis
PubMed: 35572567
DOI: 10.3389/fimmu.2022.822567