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Drug Safety 2007Plasmodium falciparum infection during pregnancy is strongly associated with maternal anaemia and low birth weight, contributing to substantial morbidity and mortality... (Review)
Review
Plasmodium falciparum infection during pregnancy is strongly associated with maternal anaemia and low birth weight, contributing to substantial morbidity and mortality in sub-Saharan Africa. Intermittent preventive treatment in pregnancy with sulfadoxine/pyrimethamine (IPTp-SP) has been one of the most effective approaches to reduce the burden of malaria during pregnancy in Africa. IPTp-SP is based on administering >or=2 treatment doses of sulfadoxine/pyrimethamine to pregnant women at predefined intervals after quickening (around 18-20 weeks). Randomised, controlled trials have demonstrated decreased rates of maternal anaemia and low birth weight with this approach. The WHO currently recommends IPTp-SP in malaria-endemic areas of sub-Saharan Africa. However, implementation has been suboptimal in part because of concerns of potential drug toxicities. This review evaluates the toxicity data of sulfadoxine/pyrimethamine, including severe cutaneous adverse reactions, teratogenicity and alterations in bilirubin metabolism. Weekly sulfadoxine/pyrimethamine prophylaxis is associated with rare but potentially fatal cutaneous reactions. Fortunately, sulfadoxine/pyrimethamine use in IPTp programmes in Africa, with 2-4 treatment doses over 6 months, has been well tolerated in multiple IPTp trials. However, sulfadoxine/pyrimethamine should not be administered concurrently with cotrimoxazole given their redundant mechanisms of action and synergistic worsening of adverse drug reactions. Therefore, HIV-infected pregnant women in malaria endemic areas who are already receiving cotrimoxazole prophylaxis should not also receive IPTp-SP. Although folate antagonist use in the first trimester is associated with neural tube defects, large case-control studies have demonstrated that sulfadoxine/pyrimethamine administered as IPTp (exclusively in the second and third trimesters and after organogenesis) does not result in an increased risk of teratogenesis. Folic acid supplementation is recommended for all pregnant women to reduce the rate of congenital anomalies but high doses of folic acid (5 mg/day) may interfere with the antimalarial efficacy of sulfadoxine/pyrimethamine. However, the recommended standard dose of folic acid supplementation (0.4 mg/day) does not affect antimalarial efficacy and may provide the optimal balance to prevent neural tube defects and maintain the effectiveness of IPTp-SP. No clinical association between sulfadoxine/pyrimethamine use and kernicterus has been reported despite the extensive use of sulfadoxine/pyrimethamine and related compounds to treat maternal malaria and congenital toxoplasmosis in near-term pregnant women and newborns. Although few drugs in pregnancy can be considered completely safe, sulfadoxine/pyrimethamine - when delivered as IPTp - has a favourable safety profile. Improved pharmacovigilance programmes throughout Africa are now needed to confirm its safety as access to IPTp-SP increases. Given the documented benefits of IPTp-SP in malaria endemic areas of Africa, access to this treatment for pregnant women should continue to expand.
Topics: Abnormalities, Drug-Induced; Africa; Animals; Antimalarials; Drug Administration Schedule; Drug Combinations; Drug Resistance; Female; Humans; Infant, Newborn; Kernicterus; Malaria, Falciparum; Plasmodium falciparum; Pregnancy; Pregnancy Complications, Parasitic; Pyrimethamine; Sulfadoxine
PubMed: 17536875
DOI: 10.2165/00002018-200730060-00003 -
Trends in Parasitology Dec 2001Chemotherapy remains the only practicable tool to control falciparum malaria in sub-Saharan Africa, where >90% of the world's burden of malaria mortality and morbidity... (Review)
Review
Chemotherapy remains the only practicable tool to control falciparum malaria in sub-Saharan Africa, where >90% of the world's burden of malaria mortality and morbidity occurs. Resistance is rapidly eroding the efficacy of chloroquine, and the combination pyrimethamine-sulfadoxine is the most commonly chosen alternative. Resistant populations of Plasmodium falciparum were selected extremely rapidly in Southeast Asia and South America. If this happens in sub-Saharan Africa, it will be a public health disaster because no inexpensive alternative is currently available. This article reviews the molecular mechanisms of this resistance and discusses how to extend the therapeutic life of antifolate drugs.
Topics: Africa South of the Sahara; Animals; Antimalarials; Chloroquine; Drug Combinations; Drug Resistance; Humans; Malaria, Falciparum; Microbial Sensitivity Tests; Mutation; Plasmodium falciparum; Pyrimethamine; Sulfadoxine; Tetrahydrofolate Dehydrogenase; Treatment Outcome
PubMed: 11756042
DOI: 10.1016/s1471-4922(01)02085-2 -
Annals of Internal Medicine May 1987The widespread emergence of chloroquine-resistant Plasmodium falciparum led to the formulation of an effective, fixed combination of two antimalarial agents,... (Review)
Review
The widespread emergence of chloroquine-resistant Plasmodium falciparum led to the formulation of an effective, fixed combination of two antimalarial agents, pyrimethamine and the long-acting sulfonamide sulfadoxine, for prophylaxis and treatment. These drugs act at sequential steps to inhibit the formation of tetrahydrofolate in the parasite. Recently, their use for malaria prophylaxis has been associated with severe, at times fatal, cutaneous reactions including erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. These reactions have necessitated a major reassessment of the indications for pyrimethamine-sulfadoxine use and increased the search for pharmacologic, immunologic and behavioral approaches to the prophylaxis and treatment of infection with P. falciparum. Pyrimethamine-sulfadoxine may be effective in preventing recurrent pneumonia caused by Pneumocystis carinii in patients with the acquired immunodeficiency syndrome, but life-threatening cutaneous reactions have also been reported in this setting.
Topics: Acquired Immunodeficiency Syndrome; Chloroquine; Drug Combinations; Drug Resistance; Humans; Malaria; Plasmodium falciparum; Pneumonia, Pneumocystis; Pyrimethamine; Sulfadoxine; Sulfanilamides; Travel
PubMed: 3551713
DOI: 10.7326/0003-4819-106-5-714 -
Viruses Dec 2020Despite the severe morbidity caused by Zika fever, its specific treatment is still a challenge for public health. Several research groups have investigated the drug...
Despite the severe morbidity caused by Zika fever, its specific treatment is still a challenge for public health. Several research groups have investigated the drug repurposing of chloroquine. However, the highly toxic side effect induced by chloroquine paves the way for the improvement of this drug for use in Zika fever clinics. Our aim is to evaluate the anti-Zika virus (ZIKV) effect of hybrid compounds derived from chloroquine and sulfadoxine antimalarial drugs. The antiviral activity of hybrid compounds (C-Sd1 to C-Sd7) was assessed in an in-vitro model of human cervical and Vero cell lines infected with a Brazilian (BR) ZIKV strain. First, we evaluated the cytotoxic effect on cultures treated with up to 200 µM of C-Sds and observed CC values that ranged from 112.0 ± 1.8 to >200 µM in cervical cells and 43.2 ± 0.4 to 143.0 ± 1.3 µM in Vero cells. Then, the cultures were ZIKV-infected and treated with up to 25 µM of C-Sds for 48 h. The treatment of cervical cells with C-Sds at 12 µM induced a reduction of 79.8% ± 4.2% to 90.7% ± 1.5% of ZIKV-envelope glycoprotein expression in infected cells as compared to 36.8% ± 2.9% of infection in vehicle control. The viral load was also investigated and revealed a reduction of 2- to 3-logs of ZIKV genome copies/mL in culture supernatants compared to 6.7 ± 0.7 × 10 copies/mL in vehicle control. The dose-response curve by plaque-forming reduction (PFR) in cervical cells revealed a potent dose-dependent activity of C-Sds in inhibiting ZIKV replication, with PFR above 50% and 90% at 6 and 12 µM, respectively, while 25 µM inhibited 100% of viral progeny. The treatment of Vero cells at 12 µM led to 100% PFR, confirming the C-Sds activity in another cell type. Regarding effective concentration in cervical cells, the EC values ranged from 3.2 ± 0.1 to 5.0 ± 0.2 µM, and the EC values ranged from 7.2 ± 0.1 to 11.6 ± 0.1 µM, with selectivity index above 40 for most C-Sds, showing a good therapeutic window. Here, our aim is to investigate the anti-ZIKV activity of new hybrid compounds that show highly potent efficacy as inhibitors of ZIKV in-vitro infection. However, further studies will be needed to investigate whether these new chemical structures can lead to the improvement of chloroquine antiviral activity.
Topics: Animals; Antiviral Agents; Cell Line; Cell Survival; Cells, Cultured; Chlorocebus aethiops; Chloroquine; Humans; Molecular Structure; Sulfadoxine; Vero Cells; Virus Replication; Zika Virus; Zika Virus Infection
PubMed: 33383619
DOI: 10.3390/v13010036 -
The Korean Journal of Parasitology Apr 2022Drug resistance is an important problem hindering malaria elimination in tropical areas. Point mutations in Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and...
Drug resistance is an important problem hindering malaria elimination in tropical areas. Point mutations in Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes confer resistance to antifolate drug, sulfadoxine-pyrimethamine (SP) while P. falciparum chloroquine-resistant transporter (Pfcrt) genes caused resistance to chloroquine (CQ). Decline in Pfdhfr/Pfdhps and Pfcrt mutations after withdrawal of SP and CQ has been reported. The aim of present study was to investigate the prevalence of Pfdhfr, Pfdhps, and Pfcrt mutation from 2 endemic areas of Thailand. All of 200 blood samples collected from western area (Thai-Myanmar) and southern area (Thai-Malaysian) contained multiple mutations in Pfdhfr and Pfdhps genes. The most prevalent haplotypes for Pfdhfr and Pfdhps were quadruple and double mutations, respectively. The quadruple and triple mutations of Pfdhfr and Pfdhps were common in western samples, whereas low frequency of triple and double mutations was found in southern samples, respectively. The Pfcrt 76T mutation was present in all samples examined. Malaria isolated from 2 different endemic regions of Thailand had high mutation rates in the Pfdhfr, Pfdhps, and Pfcrt genes. These findings highlighted the fixation of mutant alleles causing resistance of SP and CQ in this area. It is necessary to monitor the re-emergence of SP and CQ sensitive parasites in this area.
Topics: Antimalarials; Chloroquine; Drug Combinations; Drug Resistance; Humans; Malaria, Falciparum; Plasmodium falciparum; Pyrimethamine; Sulfadoxine; Thailand
PubMed: 35500892
DOI: 10.3347/kjp.2022.60.2.109 -
The Lancet. Global Health Nov 2023
Topics: Humans; Prevalence; Pyrimethamine; Sulfadoxine; Drug Combinations; Antimalarials; Plasmodium falciparum; Malaria, Falciparum; Drug Resistance
PubMed: 37858575
DOI: 10.1016/S2214-109X(23)00435-7 -
Clinical Pharmacology and Therapeutics Dec 2006Our objective was to characterize the pharmacokinetic properties of sulfadoxine-pyrimethamine in African adults and children with acute falciparum malaria. Despite...
OBJECTIVE
Our objective was to characterize the pharmacokinetic properties of sulfadoxine-pyrimethamine in African adults and children with acute falciparum malaria. Despite decades of widespread use, there are few data to inform dose recommendations.
METHODS
In a prospective multicenter pharmacokinetic study in 307 patients with acute falciparum malaria, capillary blood concentrations of sulfadoxine and pyrimethamine were determined at 9 visits over a period of 42 days by mass spectrometry.
RESULTS
After adjustment for dose, the area under the concentration-time curves (AUCs) of sulfadoxine and pyrimethamine in children aged 2 to 5 years were half of those in adults (median AUC, 410 microg/mL x d [interquartile range (IQR), 126-705 microg/mL x d] versus 816 microg/mL x d [IQR, 536-1150 microg/mL x d] [P = .0001] for sulfadoxine and 620 ng/mL x d [IQR, 229-1399 ng/mL x d] versus 1518 ng/mL x d [IQR, 1117-2013 ng/mL x d] for pyrimethamine). The effect of age on the AUC of sulfadoxine and pyrimethamine reflected higher clearance rates and larger apparent volumes of distribution in children aged 2 to 5 years when compared with adults (median clearance, 64.5 mL x kg(-1) x d(-1) [IQR, 46.2-132.6 mL x kg(-1) x d(-1)] versus 32.7 mL x kg(-1) x d(-1) [IQR, 22.3-52.2 mL x kg(-1) x d(-1)] for sulfadoxine [P = .0001] and 1.77 L x kg(-1) x d(-1) [IQR, 1.0-3.0 L x kg(-1) x d(-1)] versus 0.85 L x kg(-1) x d(-1) [IQR, 0.62-1.21 L x kg(-1) x d(-1)] for pyrimethamine [P = .0001]; median volume of distribution, 413 mL/kg [IQR, 299-711 mL/kg] versus 372 mL/kg [IQR, 267-488 mL/kg] for sulfadoxine [P = .0021] and 6.28 L/kg [IQR, 3.83-11.24 L/kg] versus 3.83 L/kg [IQR, 2.73-5.11 L/kg] for pyrimethamine [P = .0001]). Day 7 concentrations of both sulfadoxine and pyrimethamine provided good surrogate measures (R(2) >or= 0.72) of their respective AUCs.
CONCLUSIONS
Pharmacokinetic factors may contribute to the increased risk of sulfadoxine-pyrimethamine antimalarial treatment failure in young children. The current dose recommendations need revision. We predict that children aged 2 to 5 years should be treated with 1 g sulfadoxine/50 mg pyrimethamine to achieve drug concentrations equivalent to those in adults.
Topics: Adolescent; Adult; Aging; Area Under Curve; Child; Child, Preschool; Dose-Response Relationship, Drug; Drug Combinations; Female; Half-Life; Humans; Infant; Malaria, Falciparum; Male; Metabolic Clearance Rate; Pyrimethamine; Regression Analysis; Sulfadoxine
PubMed: 17178260
DOI: 10.1016/j.clpt.2006.08.016 -
Trends in Parasitology Aug 2022African children under 5 years of age bear the main burden of global malaria mortality. Seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine (SP) plus... (Review)
Review
African children under 5 years of age bear the main burden of global malaria mortality. Seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine (SP) plus amodiaquine (AQ) given monthly during the rainy season is a highly effective malaria intervention for children aged between 3 months and 5 years living in the Sahel region, a region of intense but seasonal malaria transmission. This intervention is now being considered for other regions of Africa where malaria parasites are more drug resistant. Dihydroartemisinin-piperaquine (DP), an artemisinin-based combination therapy (ACT), has proved to be highly effective and well tolerated in intermittent preventive treatment in pregnant women and children. This combination may be a suitable alternative for SMC. Understanding the safety, pharmacokinetic and pharmacodynamic properties of antimalarial combination therapies is crucial in optimising dosing.
Topics: Amodiaquine; Antimalarials; Chemoprevention; Child; Child, Preschool; Drug Combinations; Drug Therapy, Combination; Female; Humans; Infant; Malaria; Pregnancy; Pyrimethamine; Seasons; Sulfadoxine
PubMed: 35688778
DOI: 10.1016/j.pt.2022.05.003 -
Transactions of the Royal Society of... 1991
Topics: Adult; Animals; Drug Combinations; Humans; Malaria, Falciparum; Pyrimethamine; Sulfadoxine
PubMed: 1755076
DOI: 10.1016/0035-9203(91)90261-v -
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