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Gordon CA, Utzinger J, Muhi S, Becker SL, Keiser J, Khieu V, Gray DJ. Strongyloidiasis. Nat Rev Dis Primers 2024; 10:6. [PMID: 38272922 DOI: 10.1038/s41572-023-00490-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/18/2023] [Indexed: 01/27/2024]
Abstract
Strongyloidiasis is a neglected tropical disease caused primarily by the roundworm Strongyloides stercoralis. Strongyloidiasis is most prevalent in Southeast Asia and the Western Pacific. Although cases have been documented worldwide, global prevalence is largely unknown due to limited surveillance. Infection of the definitive human host occurs via direct skin penetration of the infective filariform larvae. Parasitic females reside in the small intestine and reproduce via parthenogenesis, where eggs hatch inside the host before rhabditiform larvae are excreted in faeces to begin the single generation free-living life cycle. Rhabditiform larvae can also develop directly into infectious filariform larvae in the gut and cause autoinfection. Although many are asymptomatic, infected individuals may report a range of non-specific gastrointestinal, respiratory or skin symptoms. Autoinfection may cause hyperinfection and disseminated strongyloidiasis in immunocompromised individuals, which is often fatal. Diagnosis requires direct examination of larvae in clinical specimens, positive serology or nucleic acid detection. However, there is a lack of standardization of techniques for all diagnostic types. Ivermectin is the treatment of choice. Control and elimination of strongyloidiasis will require a multifaceted, integrated approach, including highly sensitive and standardized diagnostics, active surveillance, health information, education and communication strategies, improved water, sanitation and hygiene, access to efficacious treatment, vaccine development and better integration and acknowledgement in current helminth control programmes.
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Affiliation(s)
- Catherine A Gordon
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia.
- Faculty of Medicine, University of Queensland, St Lucia, Brisbane, Queensland, Australia.
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Stephen Muhi
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, Victoria, Australia
- The University of Melbourne, Department of Microbiology and Immunology, Parkville, Victoria, Australia
| | - Sören L Becker
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Virak Khieu
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Darren J Gray
- Population Health Program, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia
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Fimbo AM, Mlugu EM, Kitabi EN, Kulwa GS, Iwodyah MA, Mnkugwe RH, Kunambi PP, Malishee A, Kamuhabwa AAR, Minzi OM, Aklillu E. Population pharmacokinetics of ivermectin after mass drug administration in lymphatic filariasis endemic communities of Tanzania. CPT Pharmacometrics Syst Pharmacol 2023; 12:1884-1896. [PMID: 37638539 PMCID: PMC10725270 DOI: 10.1002/psp4.13038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023] Open
Abstract
Ivermectin (IVM) is a drug of choice used with albendazole for mass drug administration (MDA) to halt transmission of lymphatic filariasis. We investigated IVM pharmacokinetic (PK) variability for its dose optimization during MDA. PK samples were collected at 0, 2, 4, and 6 h from individuals weighing greater than 15 kg (n = 468) receiving IVM (3-, 6-, 9-, or 12 mg) and ALB (400 mg) during an MDA campaign in Tanzania. Individual characteristics, including demographics, laboratory/clinical parameters, and pharmacogenetic variations were assessed. IVM plasma concentrations were quantified by liquid-chromatography tandem mass spectrometry and analyzed using population-(PopPK) modeling. A two-compartment model with transit absorption kinetics, and allometrically scaled oral clearance (CL/F) and central volume (Vc /F) was adapted. Fitting of the model to the data identified 48% higher bioavailability for the 3 mg dose compared to higher doses and identified a subpopulation with 97% higher mean transit time (MTT). The final estimates for CL/F, Vc /F, intercompartment clearance, peripheral volume, MTT, and absorption rate constant for a 70 kg person (on dose other than 3 mg) were 7.7 L/h, 147 L, 20.4 L/h, 207 L, 1.5 h, and 0.71/h, respectively. Monte-Carlo simulations indicated that weight-based dosing provides comparable exposure across weight bands, but height-based dosing with capping IVM dose at 12 mg for individuals with height greater than 160 cm underdoses those weighing greater than 70 kg. Variability in IVM PKs is partly explained by body weight and dose. The established PopPK model can be used for IVM dose optimization. Height-based pole dosing results in varying IVM exposure in different weight bands, hence using weighing scales for IVM dosing during MDA is recommended.
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Affiliation(s)
- Adam M. Fimbo
- Department of Global Public HealthKarolinska Institutet, Karolinska University HospitalStockholmSweden
- Tanzania Medicines and Medical Devices Authority (TMDA)Dar es SalaamTanzania
| | - Eulambius M. Mlugu
- Department of Pharmaceutics and Pharmacy Practice, School of PharmacyMuhimbili University of Health and Allied SciencesDar es SalaamTanzania
| | - Eliford Ngaimisi Kitabi
- Division of PharmacometricsOffice of Clinical Pharmacology, US Food and Drug AdministrationSilver SpringMarylandUSA
| | - Gerald S. Kulwa
- Tanzania Medicines and Medical Devices Authority (TMDA)Dar es SalaamTanzania
| | - Mohammed A. Iwodyah
- Tanzania Medicines and Medical Devices Authority (TMDA)Dar es SalaamTanzania
| | - Rajabu Hussein Mnkugwe
- Department of Clinical Pharmacology, School of Biomedical Sciences, Campus College of MedicineMuhimbili University of Health and Allied SciencesDar es SalaamTanzania
| | - Peter P. Kunambi
- Department of Clinical Pharmacology, School of Biomedical Sciences, Campus College of MedicineMuhimbili University of Health and Allied SciencesDar es SalaamTanzania
| | - Alpha Malishee
- National Institute for Medical Research, Tanga CenterTangaTanzania
| | - Appolinary A. R. Kamuhabwa
- Department of Clinical Pharmacy and Pharmacology, School of PharmacyMuhimbili University of Health and Allied SciencesDar es SalaamTanzania
| | - Omary M. Minzi
- Department of Clinical Pharmacy and Pharmacology, School of PharmacyMuhimbili University of Health and Allied SciencesDar es SalaamTanzania
| | - Eleni Aklillu
- Department of Global Public HealthKarolinska Institutet, Karolinska University HospitalStockholmSweden
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3
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Hürlimann E, Hofmann D, Keiser J. Ivermectin and moxidectin against soil-transmitted helminth infections. Trends Parasitol 2023; 39:272-284. [PMID: 36804383 DOI: 10.1016/j.pt.2023.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 02/19/2023]
Abstract
Ivermectin and moxidectin, two macrocyclic lactones, are potent antiparasitic drugs currently registered and mainly used against filarial diseases; however, their potential value for improved soil-transmitted helminth (STH) control has been acknowledged. This review provides insights on recent studies evaluating the efficacy of ivermectin and moxidectin as single or coadministered therapy against human soil-transmitted helminthiases (including Strongyloides stercoralis infections) and on pharmacokinetic/pharmacodynamic parameters measured in treated populations. Furthermore, we discuss current gaps for research, highlight advantages - but also existing challenges - for uptake of ivermectin and/or moxidectin treatment schemes into routine STH control in endemic countries.
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Affiliation(s)
- Eveline Hürlimann
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Daniela Hofmann
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
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4
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Steffens B, Koch G, Gächter P, Claude F, Gotta V, Bachmann F, Schropp J, Janner M, l'Allemand D, Konrad D, Welzel T, Szinnai G, Pfister M. Clinically practical pharmacometrics computer model to evaluate and personalize pharmacotherapy in pediatric rare diseases: application to Graves' disease. Front Med (Lausanne) 2023; 10:1099470. [PMID: 37206476 PMCID: PMC10188966 DOI: 10.3389/fmed.2023.1099470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/14/2023] [Indexed: 05/21/2023] Open
Abstract
Objectives Graves' disease (GD) with onset in childhood or adolescence is a rare disease (ORPHA:525731). Current pharmacotherapeutic approaches use antithyroid drugs, such as carbimazole, as monotherapy or in combination with thyroxine hormone substitutes, such as levothyroxine, as block-and-replace therapy to normalize thyroid function and improve patients' quality of life. However, in the context of fluctuating disease activity, especially during puberty, a considerable proportion of pediatric patients with GD is suffering from thyroid hormone concentrations outside the therapeutic reference ranges. Our main goal was to develop a clinically practical pharmacometrics computer model that characterizes and predicts individual disease activity in children with various severity of GD under pharmacotherapy. Methods Retrospectively collected clinical data from children and adolescents with GD under up to two years of treatment at four different pediatric hospitals in Switzerland were analyzed. Development of the pharmacometrics computer model is based on the non-linear mixed effects approach accounting for inter-individual variability and incorporating individual patient characteristics. Disease severity groups were defined based on free thyroxine (FT4) measurements at diagnosis. Results Data from 44 children with GD (75% female, median age 11 years, 62% receiving monotherapy) were analyzed. FT4 measurements were collected in 13, 15, and 16 pediatric patients with mild, moderate, or severe GD, with a median FT4 at diagnosis of 59.9 pmol/l (IQR 48.4, 76.8), and a total of 494 FT4 measurements during a median follow-up of 1.89 years (IQR 1.69, 1.97). We observed no notable difference between severity groups in terms of patient characteristics, daily carbimazole starting doses, and patient years. The final pharmacometrics computer model was developed based on FT4 measurements and on carbimazole or on carbimazole and levothyroxine doses involving two clinically relevant covariate effects: age at diagnosis and disease severity. Discussion We present a tailored pharmacometrics computer model that is able to describe individual FT4 dynamics under both, carbimazole monotherapy and carbimazole/levothyroxine block-and-replace therapy accounting for inter-individual disease progression and treatment response in children and adolescents with GD. Such clinically practical and predictive computer model has the potential to facilitate and enhance personalized pharmacotherapy in pediatric GD, reducing over- and underdosing and avoiding negative short- and long-term consequences. Prospective randomized validation trials are warranted to further validate and fine-tune computer-supported personalized dosing in pediatric GD and other rare pediatric diseases.
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Affiliation(s)
- Britta Steffens
- Pediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
- *Correspondence: Britta Steffens
| | - Gilbert Koch
- Pediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
| | - Pascal Gächter
- Pediatric Endocrinology and Diabetology, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
| | - Fabien Claude
- Pediatric Endocrinology and Diabetology, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
| | - Verena Gotta
- Pediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
| | - Freya Bachmann
- Department of Mathematics and Statistics, University of Konstanz, Konstanz, Germany
| | - Johannes Schropp
- Department of Mathematics and Statistics, University of Konstanz, Konstanz, Germany
| | - Marco Janner
- Division of Pediatric Endocrinology, Diabetology and Metabolism, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Dagmar l'Allemand
- Department of Pediatric Endocrinology and Diabetology, Children's Hospital of Eastern Switzerland, St. Gallen, Switzerland
| | - Daniel Konrad
- Division of Pediatric Endocrinology and Diabetology and Children's Research Centre, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Tatjana Welzel
- Pediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
| | - Gabor Szinnai
- Pediatric Endocrinology and Diabetology, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
- Department of Clinical Research, University of Basel and University Hospital Basel, Basel, Switzerland
| | - Marc Pfister
- Pediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel UKBB, University of Basel, Basel, Switzerland
- Department of Clinical Research, University of Basel and University Hospital Basel, Basel, Switzerland
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5
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Buonfrate D, Rodari P, Barda B, Page W, Einsiedel L, Watts M. Current pharmacotherapeutic strategies for Strongyloidiasis and the complications in its treatment. Expert Opin Pharmacother 2022; 23:1617-1628. [PMID: 35983698 DOI: 10.1080/14656566.2022.2114829] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Strongyloidiasis, an infection caused by the soil-transmitted helminth Strongyloides stercoralis, can lead immunocompromised people to a life-threatening syndrome. We highlight here current and emerging pharmacotherapeutic strategies for strongyloidiasis and discuss treatment protocols according to patient cohort. We searched PubMed and Embase for papers published on this topic between 1990 and May 2022. AREAS COVERED Ivermectin is the first-line drug, with an estimated efficacy of about 86% and excellent tolerability. Albendazole has a lower efficacy, with usage advised when ivermectin is not available or not recommended. Moxidectin might be a valid alternative to ivermectin, with the advantage of being a dose-independent formulation. EXPERT OPINION The standard dose of ivermectin is 200 µg/kg single dose orally, but multiple doses might be needed in immunosuppressed patients. In the case of hyperinfection, repeated doses are recommended up to 2 weeks after clearance of larvae from biological fluids, with close monitoring and further dosing based on review. Subcutaneous ivermectin is used where there is impaired intestinal absorption/paralytic ileus. In pregnant or lactating women, studies have not identified increased risk with ivermectin use. However, with limited available data, a risk-benefit assessment should be considered for each case.
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Affiliation(s)
- Dora Buonfrate
- Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria hospital, via Sempreboni 5, 37024 Negrar, Verona, Italy
| | - Paola Rodari
- Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria hospital, via Sempreboni 5, 37024 Negrar, Verona, Italy
| | - Beatrice Barda
- Ospedale La Carità, Ospedale regionale di Locarno, Locarno 6600, Switzerland
| | - Wendy Page
- Miwatj Health Aboriginal Corporation, 1424 Arnhem Rd, Nhulunbuy NT 0880, Australia
| | - Lloyd Einsiedel
- Peter Doherty Institute, University of Melbourne, 792 Elizabeth St, Melbourne VIC 3000, Australia
| | - Matthew Watts
- Centre for Infectious Diseases and Microbiology, Institute of Clinical Pathology and Medical Research - New South Wales Health Pathology and Sydney Institute for Infectious Diseases, Westmead Hospital, University of Sydney, Sydney, New South Wales, Australia
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6
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Hofmann D, Smit C, Sayasone S, Pfister M, Keiser J. Optimizing moxidectin dosing for Strongyloides stercoralis infections: Insights from pharmacometric modeling. Clin Transl Sci 2021; 15:700-708. [PMID: 34889057 PMCID: PMC8932710 DOI: 10.1111/cts.13189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 12/03/2022] Open
Abstract
Moxidectin is a frontrunner drug candidate in the treatment of strongyloidiasis. A dose of 8 mg is recommended to treat this indication, which shows a reasonably good efficacy and tolerability profile. Yet, owing to the unique life cycle of Strongyloides stercoralis (S. stercoralis) that entails internal autoinfection, a curative treatment would be desirable. Population‐based pharmacometric modeling that would help to identify an ideal dosing strategy are yet lacking. The aims of this study were to (i) explore the exposure‐efficacy response relationship of moxidectin in treating S. stercoralis and (ii) evaluate whether moxidectin treatment outcomes in terms of cure rates at baseline as compared to post‐treatment could be optimized. Our pharmacodynamic model suggests high predictive power (area under the concentration time curve‐receiver operating characteristic [AUC‐ROC] 0.817) in the probability of being cured by linking an exposure metric (i.e., AUC0‐24 or maximum concentration [Cmax]) to baseline infection intensity. Pharmacometric simulations indicate that with a minimum dose of 4 mg a maximum cure rate of ~ 95% is established in the low infection intensity group (larvae per gram [LPG] ≥0.4–1), whereas in the moderate‐to‐high intensity group (LPG >1) the cure rate plateaus at ~ 87%, following an 8 mg dose. To enhance efficacy further, studies using repeated dosing based on the duration of the autoinfection cycle, for example a two‐dose regimen 3 weeks apart should be considered. Simulations revealed similar Cmax in both treatment courses of a two‐dose regimen; hence safety should not be a concern. Collectively, our results provide evidence‐based guidance for enhanced dosing strategies and should be considered when designing future treatment strategies.
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Affiliation(s)
- Daniela Hofmann
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Cornelis Smit
- Pediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital (UKBB), Basel, Switzerland
| | - Somphou Sayasone
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.,Lao Tropical and Public Health Institute, Vientiane, Lao People's Democratic Republic
| | - Marc Pfister
- Pediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital (UKBB), Basel, Switzerland.,Certara, Princeton, New Jersey, USA
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
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Kositz C, Bradley J, Hutchins H, Last A, D'Alessandro U, Marks M. Broadening the range of use cases for ivermectin - a review of the evidence. Trans R Soc Trop Med Hyg 2021; 116:201-212. [PMID: 34323283 DOI: 10.1093/trstmh/trab114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/30/2021] [Accepted: 07/13/2021] [Indexed: 11/12/2022] Open
Abstract
Ivermectin is a broad-spectrum antiparasitic agent that interferes with glutamate-gated chloride channels found in invertebrates but not in vertebrate species. Mass drug administration (MDA) with ivermectin-based regimes has been a mainstay of elimination efforts targeting onchocerciasis and lymphatic filariasis for more than 3 decades. More recently, interest in the use of ivermectin to control other neglected tropical diseases (NTDs) such as soil-transmitted helminths and scabies has grown. Interest has been further stimulated by the fact that ivermectin displays endectocidal efficacy against various Anopheles species capable of transmitting malaria. Therefore there is growing interest in using ivermectin MDA as a tool that might aid in the control of both malaria and several NTDs. In this review we outline the evidence base to date on these emerging indications for ivermectin MDA with reference to clinical and public health data and discuss the rationale for evaluating the range of impacts of a malaria ivermectin MDA on other NTDs.
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Affiliation(s)
- Christian Kositz
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, UK
| | - John Bradley
- MRC International Statistics and Epidemiology Group, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, UK
| | - Harry Hutchins
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, UK
| | - Anna Last
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.,Hospital for Tropical Diseases, Mortimer Market Capper Street, WC1E 6JB, London, UK
| | - Umberto D'Alessandro
- Disease Control and Elimination, Medical Research Council Unit Gambia at London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, The Gambia
| | - Michael Marks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, UK.,Hospital for Tropical Diseases, Mortimer Market Capper Street, WC1E 6JB, London, UK
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8
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Smit C, Hofmann D, Sayasone S, Keiser J, Pfister M. Characterization of the Population Pharmacokinetics of Moxidectin in Adults Infected with Strongyloides Stercoralis: Support for a Fixed-Dose Treatment Regimen. Clin Pharmacokinet 2021; 61:123-132. [PMID: 34296417 PMCID: PMC8761718 DOI: 10.1007/s40262-021-01048-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2021] [Indexed: 12/03/2022]
Abstract
Background Moxidectin has recently attracted attention as a novel candidate for the treatment of helminth infections, including Strongyloides stercoralis. This study aims to characterize the population pharmacokinetics (PPK) of moxidectin in S. stercoralis-infected adults using a pharmacometric approach, and to perform model-based simulations to explore different drug dosing strategies. Methods A PPK study embedded in a dose-escalation phase IIa trial was conducted in NamBak, Laos. Eight micro blood samples were collected from each of 96 S. stercoralis-infected adults following a moxidectin dose-ranging study, from 2 to 12 mg. A PPK model was developed using nonlinear mixed-effects modeling, and dosing strategies were explored using simulations in S. stercoralis-infected subjects with varying age and body weight (n = 5000 per dosing strategy). Results A two-compartment model including delayed absorption with lag-time best described the available PK data. Allometric scaling was applied to account for the influence of body weight. High clearance was found in the infected adults (4.47 L/h [95% confidence interval 3.63–5.39] for a 70 kg individual) compared with that previously reported for healthy adults. Model-based simulations indicated similar variability in mean ± standard deviation area under the curve from time zero to infinity of 1907 ± 1552 and 2175 ± 1670 ng × h/mL in the 60–70 kg weight group, after 8 mg fixed- or weight-based dosing, respectively. Conclusion We describe the first PPK model for moxidectin in adults with S. stercoralis infection. Equivalent exposures after fixed-dose and weight-dependent dosing strategies support the use of a simple fixed-dose approach, particularly in large-scale treatment programs. Trial Registration Registered at ClinicalTrials.gov (NCT04056325). Supplementary Information The online version contains supplementary material available at 10.1007/s40262-021-01048-4.
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Affiliation(s)
- Cornelis Smit
- Pediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital (UKBB), Spitalstrasse 33, 4056, Basel, Switzerland
| | - Daniela Hofmann
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Somphou Sayasone
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Socinstrasse 57, 4051, Basel, Switzerland.,Lao Tropical and Public Health Institute, Vientiane, Lao People's Democratic Republic
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Socinstrasse 57, 4051, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Marc Pfister
- Pediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital (UKBB), Spitalstrasse 33, 4056, Basel, Switzerland. .,Certara, Princeton, NJ, USA.
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9
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Duthaler U, Leisegang R, Karlsson MO, Krähenbühl S, Hammann F. The effect of food on the pharmacokinetics of oral ivermectin. J Antimicrob Chemother 2021; 75:438-440. [PMID: 31691813 DOI: 10.1093/jac/dkz466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/01/2019] [Accepted: 10/15/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Ivermectin is an older anthelminthic agent that is being studied more intensely given its potential for mass drug administration against scabies, malaria and other neglected tropical diseases. Its pharmacokinetics (PK) remain poorly characterized. Furthermore, the majority of PK trials are performed under fasted-state dosing conditions, and the effect of food is therefore not well known. To better plan and design field trials with ivermectin, a model that can account for both conditions would be valuable. OBJECTIVES To develop a PK model and characterize the food effect with single oral doses of ivermectin. PATIENTS AND METHODS We performed a population-based PK analysis of data pooled from two previous trials of a single dose of 12 mg ivermectin, one with dosing after a high-fat breakfast (n=12) and one with fasted-state dosing (n=3). RESULTS The final model described concentration-time profiles after fed and fasted dosing accurately, and estimated the food effect associated with relative bioavailability to 1.18 (95% CI 1.10-1.67). CONCLUSIONS In this analysis, the effect of a high-fat breakfast compared with a fasted-state administration of a single oral dose of 12 mg ivermectin was minimal.
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Affiliation(s)
- Urs Duthaler
- Division of Clinical Pharmacology & Toxicology, Department of Biomedicine, University and University Hospital Basel, Switzerland
| | - Rory Leisegang
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Mats O Karlsson
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Stephan Krähenbühl
- Division of Clinical Pharmacology & Toxicology, Department of Biomedicine, University and University Hospital Basel, Switzerland
| | - Felix Hammann
- Division of Clinical Pharmacology & Toxicology, Department of Biomedicine, University and University Hospital Basel, Switzerland
- Clinical Pharmacology and Toxicology, Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Institute of Pharmacology, University of Bern, Bern, Switzerland
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10
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A systematic review and an individual patient data meta-analysis of ivermectin use in children weighing less than fifteen kilograms: Is it time to reconsider the current contraindication? PLoS Negl Trop Dis 2021; 15:e0009144. [PMID: 33730099 PMCID: PMC7968658 DOI: 10.1371/journal.pntd.0009144] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/13/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Oral ivermectin is a safe broad spectrum anthelminthic used for treating several neglected tropical diseases (NTDs). Currently, ivermectin use is contraindicated in children weighing less than 15 kg, restricting access to this drug for the treatment of NTDs. Here we provide an updated systematic review of the literature and we conducted an individual-level patient data (IPD) meta-analysis describing the safety of ivermectin in children weighing less than 15 kg. METHODOLOGY/PRINCIPAL FINDINGS A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for IPD guidelines by searching MEDLINE via PubMed, Web of Science, Ovid Embase, LILACS, Cochrane Database of Systematic Reviews, TOXLINE for all clinical trials, case series, case reports, and database entries for reports on the use of ivermectin in children weighing less than 15 kg that were published between 1 January 1980 to 25 October 2019. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42017056515. A total of 3,730 publications were identified, 97 were selected for potential inclusion, but only 17 sources describing 15 studies met the minimum criteria which consisted of known weights of children less than 15 kg linked to possible adverse events, and provided comprehensive IPD. A total of 1,088 children weighing less than 15 kg were administered oral ivermectin for one of the following indications: scabies, mass drug administration for scabies control, crusted scabies, cutaneous larva migrans, myiasis, pthiriasis, strongyloidiasis, trichuriasis, and parasitic disease of unknown origin. Overall a total of 1.4% (15/1,088) of children experienced 18 adverse events all of which were mild and self-limiting. No serious adverse events were reported. CONCLUSIONS/SIGNIFICANCE Existing limited data suggest that oral ivermectin in children weighing less than 15 kilograms is safe. Data from well-designed clinical trials are needed to provide further assurance.
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Pharmacometric Analysis of Tribendimidine Monotherapy and Combination Therapies To Achieve High Cure Rates in Patients with Hookworm Infections. Antimicrob Agents Chemother 2021; 65:AAC.00714-20. [PMID: 33139276 DOI: 10.1128/aac.00714-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 09/27/2020] [Indexed: 02/06/2023] Open
Abstract
In the treatment of hookworm infections, pharmacotherapy has been only moderately successful and drug resistance is a threat. Therefore, novel treatment options including combination therapies should be considered, in which tribendimidine could play a role. Our aims were to (i) characterize the pharmacokinetics of tribendimidine's metabolites in adolescents receiving tribendimidine monotherapy or in combination with ivermectin or oxantel pamoate, (ii) evaluate possible drug-drug interactions (DDI), (iii) link exposure to response, and (iv) identify a treatment strategy associated with high efficacy, i.e., >90% cure rates (CRs), utilizing model-based simulations. A population pharmacokinetic model was developed for tribendimidine's primary and secondary metabolites, dADT and adADT, in 54 hookworm-positive adolescents, with combination therapy evaluated as a possible covariate. Subsequently, an exposure-response analysis was performed utilizing CRs as response markers. Simulations were performed to identify a treatment strategy to achieve >90% CRs. A two-compartmental model best described metabolite disposition. No pharmacokinetic DDI was identified with ivermectin or oxantel pamoate. All participants receiving tribendimidine plus ivermectin were cured. For the monotherapy arm and the arm including the combination with oxantel pamoate, E max models adequately described the correlation between dADT exposure and probability of being cured, with required exposures to achieve 50% of maximum effect of 39.6 and 15.6 nmol/ml·h, respectively. Based on our simulations, an unrealistically high monotherapy tribendimidine dose would be necessary to achieve CRs of >90%, while combination therapy with ivermectin would meet this desired target product profile. Further clinical studies should be launched to develop this combination for the treatment of hookworm and other helminth infections.
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Gwee A, Duffull S, Zhu X, Tong SYC, Cranswick N, McWhinney B, Ungerer J, Francis J, Steer AC. Population pharmacokinetics of ivermectin for the treatment of scabies in Indigenous Australian children. PLoS Negl Trop Dis 2020; 14:e0008886. [PMID: 33284799 PMCID: PMC7746298 DOI: 10.1371/journal.pntd.0008886] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 12/17/2020] [Accepted: 10/14/2020] [Indexed: 11/30/2022] Open
Abstract
Ivermectin is a broad-spectrum antiparasitic agent used for the treatment and control of neglected tropical diseases. In Australia, ivermectin is primarily used for scabies and is licensed in children aged ≥5 years weighing >15 kg. However, young children, aged <5 years, are particularly vulnerable to scabies and its secondary complications. Therefore, this study aimed to determine an appropriate ivermectin dose for children aged 2 to 4 years and weighing ≤15 kg. We conducted a prospective, pharmacokinetic study of ivermectin in Indigenous Australian children aged between 5 and 15 years and weighing >15 kg. Doses of 200 μg/kg rounded to the nearest whole or half 3 mg tablet were given to children with scabies and ivermectin concentrations determined at two time points after dosing. A population pharmacokinetic model was developed using non-linear mixed effects modelling. A separate covariate database of children aged 2 to 4 years and weighing <15 kg was used to generate 1000 virtual patients and simulate the dose required to achieve equivalent drug exposure in young children as those aged ≥5 years. Overall, 26 children who had 48 ivermectin concentrations determined were included, 11 (42%) were male, the median age was 10.9 years and median body weight 37.6 kg. The final model was a two-compartment model with first-order absorption and linear elimination. For simulated children aged 2 to 4 years, a dose of 3 mg in children weighing 10–15 kg produced similar drug exposures to those >5 years. The median simulated area under the concentration-time curve was 976 μg∙h/L. Using modelling, we have identified a dosing strategy for ivermectin in children aged 2 to 4 years and weighing less than 15 kg that can be prospectively evaluated for safety and efficacy. Ivermectin is an important drug for the control and treatment of neglected tropical diseases. However, despite numerous studies showing that ivermectin is safe and well tolerated in young children, it is not currently recommended in young children <5 years and <15 kg. Therefore, there are no guidelines for the dose of ivermectin in young or small children. In this study, we firstly determined how much ivermectin is present in blood in children aged 5 years and older. We then used this information to model what happens to ivermectin in childrens’ bodies allowing us to calculate the dose required in children aged less than 5 years and weighing under 15 kg. This study provides a new dosing guideline that can now be tested in clinical studies of children <5 years and <15 kg.
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Affiliation(s)
- Amanda Gwee
- Department of General Medicine, The Royal Children’s Hospital Melbourne, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
- Infection and Immunity theme, Murdoch Children’s Research Institute, Parkville, Victoria, Australia
- * E-mail:
| | - Stephen Duffull
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Xiao Zhu
- Infection and Immunity theme, Murdoch Children’s Research Institute, Parkville, Victoria, Australia
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Steven Y. C. Tong
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, and Doherty Department University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Victoria, Australia
- Global and tropical health division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Noel Cranswick
- Department of General Medicine, The Royal Children’s Hospital Melbourne, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
- Infection and Immunity theme, Murdoch Children’s Research Institute, Parkville, Victoria, Australia
| | - Brett McWhinney
- Department of Chemical Pathology, Pathology Queensland, Brisbane, Queensland, Australia
| | - Jacobus Ungerer
- Department of Chemical Pathology, Pathology Queensland, Brisbane, Queensland, Australia
- Faculty of Biomedical Science, University of Queensland, Brisbane, Queensland, Australia
| | - Joshua Francis
- Global and tropical health division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Department of Paediatrics, Royal Darwin Hospital, Northern Territory, Australia
| | - Andrew C. Steer
- Department of General Medicine, The Royal Children’s Hospital Melbourne, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
- Infection and Immunity theme, Murdoch Children’s Research Institute, Parkville, Victoria, Australia
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