1
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Stevens AM, Schafer ES, Li M, Terrell M, Rashid R, Paek H, Bernhardt MB, Weisnicht A, Smith WT, Keogh NJ, Alozie MC, Oviedo HH, Gonzalez AK, Ilangovan T, Mangubat-Medina A, Wang H, Jo E, Rabik CA, Bocchini C, Hilsenbeck S, Ball ZT, Cooper TM, Redell MS. Repurposing Atovaquone as a Therapeutic against Acute Myeloid Leukemia (AML): Combination with Conventional Chemotherapy Is Feasible and Well Tolerated. Cancers (Basel) 2023; 15:cancers15041344. [PMID: 36831684 PMCID: PMC9954468 DOI: 10.3390/cancers15041344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/15/2023] [Accepted: 02/15/2023] [Indexed: 02/25/2023] Open
Abstract
Survival of pediatric AML remains poor despite maximized myelosuppressive therapy. The pneumocystis jiroveci pneumonia (PJP)-treating medication atovaquone (AQ) suppresses oxidative phosphorylation (OXPHOS) and reduces AML burden in patient-derived xenograft (PDX) mouse models, making it an ideal concomitant AML therapy. Poor palatability and limited product formulations have historically limited routine use of AQ in pediatric AML patients. Patients with de novo AML were enrolled at two hospitals. Daily AQ at established PJP dosing was combined with standard AML therapy, based on the Medical Research Council backbone. AQ compliance, adverse events (AEs), ease of administration score (scale: 1 (very difficult)-5 (very easy)) and blood/marrow pharmacokinetics (PK) were collected during Induction 1. Correlative studies assessed AQ-induced apoptosis and effects on OXPHOS. PDX models were treated with AQ. A total of 26 patients enrolled (ages 7.2 months-19.7 years, median 12 years); 24 were evaluable. A total of 14 (58%) and 19 (79%) evaluable patients achieved plasma concentrations above the known anti-leukemia concentration (>10 µM) by day 11 and at the end of Induction, respectively. Seven (29%) patients achieved adequate concentrations for PJP prophylaxis (>40 µM). Mean ease of administration score was 3.8. Correlative studies with AQ in patient samples demonstrated robust apoptosis, OXPHOS suppression, and prolonged survival in PDX models. Combining AQ with chemotherapy for AML appears feasible and safe in pediatric patients during Induction 1 and shows single-agent anti-leukemic effects in PDX models. AQ appears to be an ideal concomitant AML therapeutic but may require intra-patient dose adjustment to achieve concentrations sufficient for PJP prophylaxis.
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Affiliation(s)
- Alexandra McLean Stevens
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-(832)-824-4824; Fax: +1-(832)-825-1206
| | - Eric S. Schafer
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Minhua Li
- Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Maci Terrell
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Raushan Rashid
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hana Paek
- Department of Pharmacy, Texas Children’s Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Melanie B. Bernhardt
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Allison Weisnicht
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Wesley T. Smith
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Noah J. Keogh
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michelle C. Alozie
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hailey H. Oviedo
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alan K. Gonzalez
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tamilini Ilangovan
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Haopei Wang
- Department of Chemistry, Rice University, Houston, TX 77005, USA
| | - Eunji Jo
- Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Cara A. Rabik
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Claire Bocchini
- Department of Pediatric Infectious Diseases, Baylor College of Medicine, Houston, TX 77030, USA
| | - Susan Hilsenbeck
- Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zachary T. Ball
- Department of Chemistry, Rice University, Houston, TX 77005, USA
| | - Todd M. Cooper
- Cancer and Blood Disorders Center, Seattle Children’s Hospital, Seattle, WA 98105, USA
| | - Michele S. Redell
- Department of Pediatric Hematology/Oncology, Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
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Schnyder JL, de Jong HK, Bache EB, van Hest RM, Schlagenhauf P, Borrmann S, Hanscheid T, Grobusch MP. On the potential for discontinuing atovaquone-proguanil (AP) ad-hoc post-exposure and other abbreviated AP-regimens: Pharmacology, pharmacokinetics and perspectives. Travel Med Infect Dis 2022; 52:102520. [PMID: 36526126 DOI: 10.1016/j.tmaid.2022.102520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/30/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022]
Abstract
According to current guidelines, atovaquone-proguanil (AP) malaria chemoprophylaxis should be taken once daily starting one day before travel and continued for seven days post-exposure. However, drug-sparing regimens, including discontinuing AP after leaving malaria-endemic areas are cost-saving and probably more attractive to travelers, and may thus enhance adherence. AP has causal prophylactic effects, killing malaria parasites during the hepatic stage. If early hepatic stages were already targeted by AP, AP could possibly be discontinued upon return. Pharmacokinetic data and studies on drug-sparing AP regimens suggest this to be the case. Nevertheless, the evidence is weak and considered insufficient to modify current recommendations. Field trials require large numbers of travelers and inherently suffer from the lack of a control group. Safely-designed controlled human malaria infection trials could significantly reduce study participant numbers and safely establish an effective AP abbreviated regimen which we propose as the optimal trial design to test this concept.
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Affiliation(s)
- Jenny L Schnyder
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
| | - Hanna K de Jong
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
| | - Emmanuel B Bache
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
| | - Reinier M van Hest
- Department of Hospital Pharmacy & Clinical Pharmacology, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
| | - Patricia Schlagenhauf
- University of Zurich Centre for Travel Medicine, WHO Collaborating Centre for Travelers' Health, Department of Public and Global Health, Military Medicine Biology Competence Centre, Institute for Epidemiology, Biostatistics and Prevention, Zurich, Switzerland
| | - Steffen Borrmann
- Institute of Tropical Medicine, German Centre for Infection Research (DZIF), University of Tübingen, Tübingen, Germany; Centre de Recherches Médicales en Lambaréné (CERMEL), Lambaréné, Gabon
| | - Thomas Hanscheid
- Instituto de Microbiologia, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Martin P Grobusch
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands; Institute of Tropical Medicine, German Centre for Infection Research (DZIF), University of Tübingen, Tübingen, Germany; Centre de Recherches Médicales en Lambaréné (CERMEL), Lambaréné, Gabon; Masanga Medical Research Unit (MMRU), Masanga, Sierra Leone; Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa.
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3
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Stevens AM, Xiang M, Heppler LN, Tošić I, Jiang K, Munoz JO, Gaikwad AS, Horton TM, Long X, Narayanan P, Seashore EL, Terrell MC, Rashid R, Krueger MJ, Mangubat-Medina AE, Ball ZT, Sumazin P, Walker SR, Hamada Y, Oyadomari S, Redell MS, Frank DA. Atovaquone is active against AML by upregulating the integrated stress pathway and suppressing oxidative phosphorylation. Blood Adv 2019; 3:4215-4227. [PMID: 31856268 PMCID: PMC6929386 DOI: 10.1182/bloodadvances.2019000499] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 11/11/2019] [Indexed: 12/31/2022] Open
Abstract
Atovaquone, a US Food and Drug Administration-approved antiparasitic drug previously shown to reduce interleukin-6/STAT3 signaling in myeloma cells, is well tolerated, and plasma concentrations of 40 to 80 µM have been achieved with pediatric and adult dosing. We conducted preclinical testing of atovaquone with acute myeloid leukemia (AML) cell lines and pediatric patient samples. Atovaquone induced apoptosis with an EC50 <30 µM for most AML lines and primary pediatric AML specimens. In NSG mice xenografted with luciferase-expressing THP-1 cells and in those receiving a patient-derived xenograft, atovaquone-treated mice demonstrated decreased disease burden and prolonged survival. To gain a better understanding of the mechanism of atovaquone, we performed an integrated analysis of gene expression changes occurring in cancer cell lines after atovaquone exposure. Atovaquone promoted phosphorylation of eIF2α, a key component of the integrated stress response and master regulator of protein translation. Increased levels of phosphorylated eIF2α led to greater abundance of the transcription factor ATF4 and its target genes, including proapoptotic CHOP and CHAC1. Furthermore, atovaquone upregulated REDD1, an ATF4 target gene and negative regulator of the mechanistic target of rapamycin (mTOR), and caused REDD1-mediated inhibition of mTOR activity with similar efficacy as rapamycin. Additionally, atovaquone suppressed the oxygen consumption rate of AML cells, which has specific implications for chemotherapy-resistant AML blasts that rely on oxidative phosphorylation for survival. Our results provide insight into the complex biological effects of atovaquone, highlighting its potential as an anticancer therapy with novel and diverse mechanisms of action, and support further clinical evaluation of atovaquone for pediatric and adult AML.
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MESH Headings
- Activating Transcription Factor 4/metabolism
- Adolescent
- Animals
- Apoptosis/drug effects
- Atovaquone/pharmacology
- Cell Line, Tumor
- Cell Survival/drug effects
- Child
- Child, Preschool
- Disease Models, Animal
- Female
- Humans
- Infant
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/mortality
- Leukemia, Myeloid, Acute/pathology
- Male
- Mice
- Mice, Knockout
- Oxidative Phosphorylation/drug effects
- Signal Transduction/drug effects
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Alexandra M Stevens
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Michael Xiang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Lisa N Heppler
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Isidora Tošić
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Department of Biochemistry, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Kevin Jiang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Jaime O Munoz
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Amos S Gaikwad
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Terzah M Horton
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Xin Long
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Padmini Narayanan
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Elizabeth L Seashore
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Maci C Terrell
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Raushan Rashid
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Michael J Krueger
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | | | | | - Pavel Sumazin
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Sarah R Walker
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; and
| | - Yoshimasa Hamada
- Division of Molecular Biology, Institute for Genome Research, and
- Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Seiichi Oyadomari
- Division of Molecular Biology, Institute for Genome Research, and
- Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Michele S Redell
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - David A Frank
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; and
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4
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Abstract
Pneumocystis carinii pneumonia (PCP) remains a serious infection in the immunocompromised host (in the absence of HIV infection) and presents significant management and diagnostic challenges to ICU physicians. Non-HIV PCP is generally abrupt in onset, and follows a fulminate course with high rates of hospitalization, ICT admission, respiratory failure, and requirement for intubation. Mortality is generally high, especially if mechanical ventilation is required. Non-invasive ventilatory support may be considered, although the rapid progression to respiratory failure often necessitates intubation at the time of presentation. Bronchoscopy is often required to establish the diagnosis, and empirical antimicrobial treatment specifically targeted to P. carinii should be initiated while awaiting confirmation. Adjunctive corticosteroids may accelerate recovery, although their use has not yet been established in non-HIV PCP. For the ICU physicians to diagnose PCP, the non-specific presentation of an acute febrile illness and respiratory distress with diffuse pulmonary infiltrates requires a high clinical index of suspician, familiarity with clinical conditions associated with increased risk for PCP, and a low threshold for bronchoscopy to establish the diagnosis.
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Affiliation(s)
- Geoffrey S. Gilmartin
- Division of Pulmonary and Critical Care, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Henry Koziel
- Division of Pulmonary and Critical Care, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.,
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5
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Amet S, Zimner-Rapuch S, Launay-Vacher V, Janus N, Deray G. Malaria Prophylaxis in Patients with Renal Impairment. Drug Saf 2013; 36:83-91. [DOI: 10.1007/s40264-013-0017-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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6
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Nixon GL, Moss DM, Shone AE, Lalloo DG, Fisher N, O'Neill PM, Ward SA, Biagini GA. Antimalarial pharmacology and therapeutics of atovaquone. J Antimicrob Chemother 2013; 68:977-85. [PMID: 23292347 PMCID: PMC4344550 DOI: 10.1093/jac/dks504] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Atovaquone is used as a fixed-dose combination with proguanil (Malarone) for treating children and adults with uncomplicated malaria or as chemoprophylaxis for preventing malaria in travellers. Indeed, in the USA, between 2009 and 2011, Malarone prescriptions accounted for 70% of all antimalarial pre-travel prescriptions. In 2013 the patent for Malarone will expire, potentially resulting in a wave of low-cost generics. Furthermore, the malaria scientific community has a number of antimalarial quinolones with a related pharmacophore to atovaquone at various stages of pre-clinical development. With this in mind, it is timely here to review the current knowledge of atovaquone, with the purpose of aiding the decision making of clinicians and drug developers involved in the future use of atovaquone generics or atovaquone derivatives.
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Affiliation(s)
- Gemma L Nixon
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
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7
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Cyclodextrin/poly(anhydride) nanoparticles as drug carriers for the oral delivery of atovaquone. Biomed Microdevices 2011; 13:1015-25. [DOI: 10.1007/s10544-011-9571-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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8
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Petersen I, Eastman R, Lanzer M. Drug-resistant malaria: molecular mechanisms and implications for public health. FEBS Lett 2011; 585:1551-62. [PMID: 21530510 DOI: 10.1016/j.febslet.2011.04.042] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 04/15/2011] [Accepted: 04/18/2011] [Indexed: 10/18/2022]
Abstract
Resistance to antimalarial drugs has often threatened malaria elimination efforts and historically has led to the short-term resurgence of malaria incidences and deaths. With concentrated malaria eradication efforts currently underway, monitoring drug resistance in clinical settings complemented by in vitro drug susceptibility assays and analysis of resistance markers, becomes critical to the implementation of an effective antimalarial drug policy. Understanding of the factors, which lead to the development and spread of drug resistance, is necessary to design optimal prevention and treatment strategies. This review attempts to summarize the unique factors presented by malarial parasites that lead to the emergence and spread of drug resistance, and gives an overview of known resistance mechanisms to currently used antimalarial drugs.
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Affiliation(s)
- Ines Petersen
- Department of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Heidelberg, Germany.
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9
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Gurule S, Goswami D, Khuroo AH, Monif T. LC-APCI mass spectrometric method development and validation for the determination of atovaquone in human plasma. Biomed Chromatogr 2010; 24:497-505. [PMID: 19711297 DOI: 10.1002/bmc.1317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A newly developed LC-APCI mass spectrometric method is described for human plasma determination of atovaquone using lapachol internal standard. A single-step protein precipitation technique for plasma extraction of atovaquone achieving mean recovery of 94.17% (CV 8%) without compromising sensitivity (limit of quantitation 50.3 ng/mL) or linearity (50.3 ng/mL-23924.6 ng/mL) is delineated in this paper. Heated nebulizer in negative multiple reaction monitoring mode was employed with transitions m/z 365.2 --> m/z 337.1 and m/z 240.9 --> m/z 185.7 for atovaquone and lapachol respectively in this liquid chromatographic-tandem mass spectrometric method. Excellent chromatographic separation on a Synergi 4 micro Polar-RP 80A (150 x 2.0 mm) column, using 100 microL of plasma extraction volume along with 10 microL of injection load, completing analysis run-time within 2.5 min, highlights this simple yet unique bioanalytical method. The developed method can be successfully applied to pharmacokinetic studies on atovaquone suspension administered in healthy volunteers or HIV-infected patients. Moreover full method validation results not published before are presented and discussed in detail for the first time in this article.
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Affiliation(s)
- Sanjay Gurule
- Department of Clinical Pharmacology and Pharmacokinetics, Ranbaxy Laboratories Ltd, Gurgaon, Haryana, India
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10
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Affiliation(s)
- Aaron L Baggish
- University of Connecticut School of Medicine, Farmington, Connecticut, USA
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11
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Schöler N, Krause K, Kayser O, Müller RH, Borner K, Hahn H, Liesenfeld O. Atovaquone nanosuspensions show excellent therapeutic effect in a new murine model of reactivated toxoplasmosis. Antimicrob Agents Chemother 2001; 45:1771-9. [PMID: 11353624 PMCID: PMC90544 DOI: 10.1128/aac.45.6.1771-1779.2001] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immunocompromised patients are at risk of developing toxoplasma encephalitis (TE). Standard therapy regimens (including sulfadiazine plus pyrimethamine) are hampered by severe side effects. While atovaquone has potent in vitro activity against Toxoplasma gondii, it is poorly absorbed after oral administration and shows poor therapeutic efficacy against TE. To overcome the low absorption of atovaquone, we prepared atovaquone nanosuspensions (ANSs) for intravenous (i.v.) administration. At concentrations higher than 1.0 microg/ml, ANS did not exert cytotoxicity and was as effective as free atovaquone (i.e., atovaquone suspended in medium) against T. gondii in freshly isolated peritoneal macrophages. In a new murine model of TE that closely mimics reactivated toxoplasmosis in immunocompromised hosts, using mice with a targeted mutation in the gene encoding the interferon consensus sequence binding protein, i.v.-administered ANS doses of 10.0 mg/kg of body weight protected the animals against development of TE and death. Atovaquone was detectable in the sera, brains, livers, and lungs of mice by high-performance liquid chromatography. Development of TE and mortality in mice treated with 1.0- or 0.1-mg/kg i.v. doses of ANS did not differ from that in mice treated orally with 100 mg of atovaquone/kg. In conclusion, i.v. ANSs may prove to be an effective treatment alternative for patients with TE.
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Affiliation(s)
- N Schöler
- Institute for Infection Medicine, Department of Medical Microbiology and Immunology of Infection, Benjamin Franklin Medical Center, D-12203 Berlin, Germany
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12
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Chou CC, Brown MP, Merritt KA. Capillary zone electrophoresis for the determination of atovaquone in serum. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 742:441-5. [PMID: 10901150 DOI: 10.1016/s0378-4347(00)00183-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A rapid and simple capillary zone electrophoresis (CZE) method has been developed for the determination of atovaquone in serum. The drug was extracted from equine serum-chloroform (1:3, v/v) at greater than 80% recovery and assayed in buffer containing 25 mM sodium borate (pH 9.1) and 25% acetonitrile. A 100 microm I.D. fused-silica capillary was used and the detection was by UV-diode array at 254 nm; the migration time was approximately 8 min. Intra- and inter-assay variabilities were less than 7.8% and 5.8%, respectively, and the accuracy of the assay (expressed as % bias) ranged from 4.5 to -5.2%. The working assay range was from 2 to 100 microg/ml. This sensitivity could be increased by concentrating during the extraction procedure. Replacement of acetonitrile with 75 mM surfactant 3-(dimethyldodecylammonio)propanesulfonate gave similar sensitivity and provided an additional option to facilitate the separation of atovaquone on multiple-drug samples.
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Affiliation(s)
- C C Chou
- Department of Large Animal and Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
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13
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Falloon J, Sargent S, Piscitelli SC, Bechtel C, LaFon SW, Sadler B, Walker RE, Kovacs JA, Polis MA, Davey RT, Lane HC, Masur H. Atovaquone suspension in HIV-infected volunteers: pharmacokinetics, pharmacodynamics, and TMP-SMX interaction study. Pharmacotherapy 1999; 19:1050-6. [PMID: 10610011 DOI: 10.1592/phco.19.13.1050.31598] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To evaluate the pharmacokinetics and safety of atovaquone suspension in volunteers infected with the human immunodeficiency virus ((HIV). DESIGN Open-label, nonrandomized study. SETTING Two clinical research centers. PATIENTS Twenty-two HIV-infected volunteers with a median CD4 cell count of 37 cells/mm3. INTERVENTIONS Patients received atovaquone suspension fasting or fed for 2-week periods with crossover at dosages of 500 mg/day, and randomization to fasting or fed at dosages of 750 and 1000 mg/day. A subset of patients also received 750 mg twice/day with food, and a subset of those who received 1000 mg/day fasting also received 1000 mg with food. During a long-term dosing phase, a subset of subjects were evaluated for an interaction between atovaquone and trimethoprim-sulfamethoxazole (TMP-SMX). MEASUREMENTS AND MAIN RESULTS Average steady-state atovaquone concentrations at 500 mg were 6.7 +/- 3.2 microg/ml fasted and 11.3 +/- 5.0 microg/ml with food; at 750 mg, 9.9 +/- 7.1 microg/ml fasted and 12.5 +/- 5.9 microg/ml with food; at 1000 mg, 9.7 +/- 4.3 microg/ml fasted and 13.6 +/- 5.0 microg/ml with food; and at 1500 mg, 21.1 +/- 5.0 microg/ml with food. Thus, plasma concentrations were not proportional to dose. Concomitant food ingestion resulted in a 1.3- to 1.7-fold increase in values. Average steady-state concentrations were less than 10 microg/ml in 21% and more than 15 microg/ml in 36% of patients at 1000 mg/day with food; at 750 mg twice/day, all five patients had levels above 15 microg/ml. Atovaquone suspension was well tolerated; diarrhea, nausea, fatigue, and rash were the most common adverse events. Concomitant administration of TMP-SMX did not change atovaquone concentrations and resulted in small decreases in concentrations of TMP (16%) and SMX (10%). CONCLUSION Plasma concentrations are significantly higher when atovaquone suspension is administered with food compared with fasting. Total doses of 1500 mg/day are likely to achieve concentrations effective for prophylaxis of Pneumocystis carinii pneumonia.
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Affiliation(s)
- J Falloon
- National Institute of Allergy and Infectious Diseases and the Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1880, USA
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14
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Freeman CD, Klutman NE, Lamp KC, Dall LH, Strayer AH. Relative bioavailability of atovaquone suspension when administered with an enteral nutrition supplement. Ann Pharmacother 1998; 32:1004-7. [PMID: 9793589 DOI: 10.1345/aph.17464] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To compare the relative bioavailability of a single atovaquone 750 mg suspension oral dose when administered in the fasting state, after a normal breakfast, and after an enteral nutrition supplement. DESIGN Ten healthy volunteers received a single dose of atovaquone suspension 750 mg/5 mL while fasting. At 2-week intervals, the subjects were then randomized in a crossover design to receive the atovaquone dose within 1 hour of consuming a normal breakfast (fat content 21 g) and 16 oz. of Sustacal Plus (fat content 28 g). Blood samples were collected at seven time points after each atovaquone dose. HPLC was used to determine the atovaquone concentrations in plasma. RESULTS Administering atovaquone suspension with either a normal breakfast or an enteral nutrition supplement, such as Sustacal Plus, significantly increased the oral relative bioavailability. The mean AUC0-24 after the fasting dose was 43.4 micrograms.h/mL. The mean AUC0-24 values with breakfast (103.8 micrograms.h/mL) and Sustacal Plus (118.8 micrograms.h/mL) were significantly greater compared with fasting (p < 0.0001). CONCLUSIONS This study has shown that the new atovaquone oral suspension also has significantly greater bioavailability when administered after food or a nutrition supplement that has a moderate fat content. Patients who require atovaquone therapy can use Sustacal Plus without risk of reduced absorption.
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Affiliation(s)
- C D Freeman
- School of Medicine, University of Missouri-Kansas City, USA
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15
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Abstract
OBJECTIVE To provide a complication of relevant information on drug interactions to assist healthcare practitioners in managing complex HIV-related pharmacotherapy. DATA SOURCES Information was retrieved via a MEDLINE search (January 1966-December 1996) using MeSH headings "human immunodeficiency virus," "drug interactions," and names of medications commonly prescribed for the management of HIV infection and related opportunistic infections. Abstracts of international and national conferences, review articles, textbooks, and references of all articles were also searched. STUDY SELECTION AND DATA EXTRACTION All literature on pharmacokinetic or pharmacodynamic interactions was considered for inclusion. Pertinent information, as assessed by the authors, was selected and summarized for discussion. DATA SYNTHESIS Drug disposition and/or pharmacologic effect may be affected either by HIV-related physiologic changes or by the presence of concomitant drug therapy. Modifications in drug selection, dosage, dosing regimen, or route of administration may be needed to avoid or manage drug-disease, drug-drug, or drug-food interactions. Management options may depend on the mechanism and the clinical significance of the interaction, the availability of therapeutic alternatives, patient convenience, and cost restrictions. In the absence of specific data, consideration of pharmacokinetic and pharmacodynamic characteristics to assist practitioners in predicting the likelihood of possible interactions was included. RESULTS A comprehensive table of clinically significant drug interactions is provided. Drug interaction principles and practical management strategies are also discussed. CONCLUSIONS The potential for drug interactions is extremely common, given the increasing complexity of managing patients infected with HIV. To avoid compromising therapeutic efficacy or increasing drug toxicity, practitioners need to be aware of potential interactions and are encouraged to use a systematic approach when managing patient drug therapy.
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Hussein Z, Eaves J, Hutchinson DB, Canfield CJ. Population pharmacokinetics of atovaquone in patients with acute malaria caused by Plasmodium falciparum. Clin Pharmacol Ther 1997; 61:518-30. [PMID: 9164414 DOI: 10.1016/s0009-9236(97)90132-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The population pharmacokinetics of atovaquone were examined in 458 black, Oriental, and Malay patients with acute Plasmodium falciparum malaria receiving atovaquone alone or concomitantly with other drugs. Oral clearance (CL/F) showed a 0.674 power relationship with weight and is similar in Oriental and Malay subjects but 58.5% lower in black subjects. On the basis of mean body weight, the population estimate of CL/F is 3.28, 8.49, and 9.13 L/hr in black, Oriental, and Malay subjects, respectively. The relationship between apparent volume of distribution (V area/F) and weight was linear and similar in all three races at 7.98 L/kg. The population estimate of V area/F is 345, 383, and 428 L in black, Oriental, and Malay subjects, respectively. The bioavailability of the high and low doses of atovaquone was similar. Neither CL/F nor V area/F were significantly affected by age, gender, and the coadministration with chloroguanide (proguanil), pyrimethamine, and tetracycline. Half-life (t1/2) showed a 0.326 power relationship with weight; thus, the population estimate of t1/2 in black, Oriental, and Malay subjects is 72.9, 31.3, and 32.5 hours, respectively. The final magnitudes of interpatient variability in CL/F and V area/F were 68% and 49%, respectively.
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Affiliation(s)
- Z Hussein
- Glaxo Wellcome, Beckenham, and Pharmaceutical Systems Inc., Talent, Oregon, USA
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17
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Abstract
BACKGROUND The increasing spread of multidrug-resistant Plasmodium falciparum malaria emphasises the urgent need for alternative treatment regimens. The objective of the study was to establish the efficacy of a novel drug combination. We compared a combination of atovaquone and proguanil with amodiaquine in the treatment of acute uncomplicated P falciparum malaria in Lambaréné, Gabon. METHODS 142 adults were randomly allocated either a combination treatment of atovaquone 1000 mg daily and proguanil 400 mg daily for 3 days or treatment with amodiaquine 600 mg on admission, 600 mg 24 h later, and 300 mg after a further 24 h. Symptoms and clinical signs were recorded and giemsa-stained thick blood smears were done every 12 h until patients had been symptom-free and aparasitaemic for 24 h. 126 patients were followed up for 28 days or until recrudescence. FINDINGS In the atovaquone plus proguanil group 62 (87%) of 71 patients were cured and only one had recrudescent infection. By contrast, the cure rate was significantly lower (p=0.022) with amodiaquine (51 [72%] of 71; there were 12 recrudescences in the amodiaquine group). Eight patients in each group were lost to follow-up. Patients treated with atovaquone plus proguanil complained of nausea (33%) and vomiting (29%), and the most commonly reported adverse effects of amodiaquine were pruritus (43%) and insomnia (27%). INTERPRETATION Atovaquone and proguanil was a highly effective and safe drug combination in patients with acute uncomplicated P falciparum malaria in Gabon.
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Affiliation(s)
- P D Radloff
- International Research Laboratory, Albert Schweitzer Hospital, Lambaréné, Gabon
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18
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Hannan SL, Ridout GA, Jones AE. Determination of the potent antiprotozoal compound atovaquone in plasma using liquid-liquid extraction followed by reversed-phase high-performance liquid chromatography with ultraviolet detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 678:297-302. [PMID: 8738034 DOI: 10.1016/0378-4347(95)00497-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A specific and robust method is presented for the determination of atovaquone in plasma. Atovaquone is a potent antiprotozoal compound for use in immunocompromised patients who are intolerant of conventional therapies. The method involves a liquid-liquid extraction of the compound into hexane modified with 2% (v/v) isoamyl alcohol. The processed extracts are analysed by reversed-phase high-performance liquid chromatography with ultraviolet detection at 254 nm. The assay has a limit of quantification of 0.1 microgram/ml and is linear between 0.1 and 50 micrograms/ml. The method has been applied to many clinical studies and has been demonstrated to be precise and accurate with high sample throughput. Atovaquone is not significantly metabolised in humans.
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Affiliation(s)
- S L Hannan
- Wellcome Research Laboratories, Beckenham, Kent, UK
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19
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Dixon R, Pozniak AL, Watt HM, Rolan P, Posner J. Single-dose and steady-state pharmacokinetics of a novel microfluidized suspension of atovaquone in human immunodeficiency virus-seropositive patients. Antimicrob Agents Chemother 1996; 40:556-60. [PMID: 8851570 PMCID: PMC163157 DOI: 10.1128/aac.40.3.556] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The single- and multiple-dose pharmacokinetics of and tolerability to a new microfluidized suspension of atovaquone were studied in human immunodeficiency virus-seropositive patients with CD4 counts of < or = 200 cells per mm3 in order to define a dosing regimen for the treatment of Pneumocystis carinii pneumonia. This was an open study with groups of six patients each. In the first part of the study, six subjects received escalating single doses of 500, 1,000, and 1,500 mg after an overnight fast at weekly intervals. In the second part of the study, groups of six subjects were dosed for 14 days according to three regimens: 1,000 mg twice daily fasting, twice daily with a high-fat meal, or once daily with a high-fat meal. Plasma atovaquone levels were assayed by high-performance liquid chromatography. Pharmacokinetic parameters were determined by noncompartmental methods, and statistical comparison of parameters for single doses was performed by analysis of variance. Plasma drug concentrations increased with single doses from 500 to 1,000 mg but were no higher with a dose of 1,500 mg. Thus, 1,000 mg was selected for multiple administration. A regimen of 1,000 mg twice daily with food resulted in a 93% increase in the average trough steady-state concentration compared with 1,000 mg once daily with food. Food increased the bioavailability of atovaquone 1.4-fold over that in the fasting state. All patients who received 1,000 mg twice daily with food achieved target steady-state concentrations in plasma of 15 to 25 micrograms/ml. Multiple-dose regimens were generally well tolerated, but the higher levels in plasma achieved by 1,000 mg twice daily with food were associated with an increased incidence of rash. In conclusion, target plasma atovaquone concentrations for the treatment of P. carinii pneumonia can be achieved in most patients with 1,000 mg twice daily in a fasting state and in all patients with 1,000 mg twice daily administered with food, but at higher concentrations in plasma, there may be an increased risk of rash.
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Affiliation(s)
- R Dixon
- Department of Clinical Pharmacology, Wellcome Research Laboratories, Kent, United Kingdom
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20
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21
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Studenberg SD, Long JD, Woolf JH, Bruner CJ, Wilson D, Woolley JL. A robotics-based liquid chromatographic assay for the measurement of atovaquone in plasma. J Pharm Biomed Anal 1995; 13:1383-93. [PMID: 8634356 DOI: 10.1016/0731-7085(95)01563-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A precise and specific robotics-based liquid chromatographic (LC) method for measuring atovaquone concentrations in plasma was developed and validated, and the method was compared with an existing manual LC method. The compound was isolated from plasma by liquid-liquid extraction, separated by reversed-phase LC, and quantitated against an internal standard with UV detection. Least-squares linear regression with 1/concentration2 weighting was used as the calibration model. The range of the calibration curve for the assay under routine conditions was 0.25-50 micrograms ml-1. No endogenous interferences with the compound or the internal standard were noted in either untreated human plasma or in plasma from patients enrolled in Phase III clinical trials of atovaquone. The accuracy of the assay (determined as the percent bias) ranged from -4.8% to -9.4% in the validation runs. The intra- and interassay precisions (determined as the relative standard deviation) were less than 6.8% and 6.4%, respectively. The contribution of an internal standard on assay accuracy and precision also was examined. Interassay variability was marginally improved by the incorporation of an internal standard to the assay; accuracy and intra-assay precision were essentially unchanged. A paired t-test between estimates of atovaquone concentrations in healthy volunteer and HIV + patient human plasma samples assayed by the automated and manual methods demonstrated no significant difference (p = 0.31) between the values determined by each method.
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Affiliation(s)
- S D Studenberg
- Division of Pharmacokinetics and Drug Metabolism, Wellcome Research Laboratories, Research Triangle Park, NC 27709, USA
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22
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Nahata MC, Brady MT. Pharmacokinetics of fluconazole after oral administration in children with human immunodeficiency virus infection. Eur J Clin Pharmacol 1995; 48:291-3. [PMID: 7589057 DOI: 10.1007/bf00198314] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The objective of this study was to determine the pharmacokinetics of fluconazole after oral administration in children with human immunodeficiency virus (HIV) infection. After an overnight fast, a single dose of either 2 mg.kg-1 or 8 mg.kg-1 was administered in a suspension; five children received 2 mg.kg-1 and four 8 mg.kg-1 (ages 5-13 years). Blood samples were collected at various times on day 1, and once daily on days 2-7 after the dose. Fluconazole serum concentrations were measured by gas chromatography. At the dose of 2 mg.kg-1, the Cmax, AUC (0-infinity), and t1/2 ranged from 2.3-4.4 micrograms.ml-1, 84.9-136 micrograms.h.ml-1, and 19.8-34.8 h, respectively. At the dose of 8 mg.kg-1 the Cmax, AUC (0-infinity), and t1/2 ranged from 5.4-12.1 micrograms.ml-1, 330-684 micrograms h.ml-1, and 25.6-42.3 h, respectively. When compared with published data in healthy adults, fluconazole achieved similar serum concentrations in the present group of children, indicating a nearly complete degree of absorption.
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Affiliation(s)
- M C Nahata
- College of Pharmacy, Ohio State University, Wexner Institute for Pediatric Research, Children's Hospital, Columbus 43210, USA
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23
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Albesa I, Bogdanov P, Eraso A, Sperandeo NR, de Bertorello MM. Antibiotic activity of isoxazolylnaphthoquinone imines on mice infected with Staphylococcus aureus. THE JOURNAL OF APPLIED BACTERIOLOGY 1995; 78:373-7. [PMID: 7744722 DOI: 10.1111/j.1365-2672.1995.tb03420.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The antibiotic activity of new synthetic isoxazolylnaphthoquinone imines was studied. Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922 were resistant to the four compounds studied (MIC > 128 micrograms ml-1), but Staphylococcus aureus ATCC 25923, ATCC 29213 and 30 clinical isolates of Staph. aureus were inhibited by 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1,4-naphthoquinone-4-imine (I). This compound diminished bloodstream infection of mice injected i.m. with Staph. aureus; septicaemia decayed significantly when I was applied at the beginning of the infection while when I was given 3 d after bacterial challenge, a significant protection was afforded. Bactericidal activity in serum increased during the 5 h after I was administered i.p. The acetyl derivative of I had a high MIC but when inoculated orally in mice decreased the Staph. aureus counts in circulation. This protection occurred only when the schedule of administration started close to the bacterial challenge. Antibiotic activity in vivo may be associated with in vitro effects.
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Affiliation(s)
- I Albesa
- Departamento de Farmacia, Facultad de Ciencias et Químicas, Universidad Nacional de Córdoba, Argentina
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24
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Maddix DS. Atovaquone: A Review with Emphasis on its Role in the Treatment of Pneumocystis Carinii Pneumonia. J Pharm Technol 1994. [DOI: 10.1177/875512259401000405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective: To discuss the mechanism of action, in vitro and in vivo activity, pharmacokinetics, clinical trials, adverse effects, drug interactions, and dosage guidelines of atovaquone. Data Sources: Pertinent literature published since 1988 was identified via a MEDLINE search. Published proceedings of selected conferences were also used. Study Selection: All basic science, microbiologic, and pharmacokinetic articles were evaluated. Since only limited data regarding atovaquone are available in the literature, all clinical trials involving the use of atovaquone in the treatment of Pneumocystis carinii pneumonia were reviewed. Data Synthesis: Atovaquone is an antiprotozoal agent that was recently approved for the treatment of mild to moderate P. carinii pneumonia (PCP) in patients who are intolerant of trimethoprim/sulfamethoxazole (TMP/SMX). The exact mechanism of action of atovaquone against P. carinii has not been determined. The drug has in vitro and in vivo activity against P. carinii, Toxoplasma gondii, and Plasmodium species. The bioavailability of oral atovaquone is highly variable. The drug must be administered with food to enhance absorption. In a double-blind comparative trial in AIDS patients with mild to moderate PCP, those who were treated with atovaquone had a significantly higher mortality rate than those treated with TMP/SMX. More patients who received TMP/SMX experienced adverse effects that resulted in discontinuation of therapy. Conclusions: Because of concerns of increased mortality in atovaquone recipients, the drug should be reserved for the treatment of mild to moderate PCP in patients who are unable to tolerate TMP/SMX and trimethoprim-dapsone.
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25
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Epstein LJ, Mohsenifar Z, Daar ES, Yeh V, Meyer RD. Clinical experience with atovaquone: a new drug for treating Pneumocystis carinii pneumonia. Am J Med Sci 1994; 308:5-8. [PMID: 8010339 DOI: 10.1097/00000441-199407000-00003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Atovaquone is a new hydroxynapthoquinone antiprotozoal agent active against Pneumocystis carinii in vitro and in animal models. The authors report an experience using atovaquone to treat 25 patients with mild to moderate P. carinii pneumonia. Eligible patients were treated for 21 days with 750 mg of atovaquone orally three times daily. Prednisone was added when the P(A-a)O2 gradient was between 35-45 mm Hg. Patients were treated under three treatment protocols. Patients in Group 1 participated in one of two randomized comparative drug trials, designed for patients with and without sulfonamide intolerance. Six of seven patients successfully completed treatment, and one patient discontinued treatment because of an adverse reaction (> 5 times baseline increase in transaminase level). Patients in Group 2 were treated with atovaquone for mild to moderate P. carinii pneumonia under a treatment Investigational New Drug protocol because of prior sulfonamide reactions. Fifteen of these 18 patients successfully completed treatment; one died from other complications during treatment and two discontinued treatment for adverse reactions (> 5 times baseline increase in transaminase levels, and a diffuse rash). Serum transaminase levels returned to normal at the end of treatment in all patients with elevated levels. All patients demonstrated clinical resolution of their pneumonia and improvement of pretreatment hypoxemia (Group 1: pretreatment PaO2 = 82 +/- 14 mm Hg, posttreatment PaO2 = 92 +/- 9 mm Hg). Overall, 21 (84%) of 25 patients successfully finished therapy without significant adverse reactions. Atovaquone appears to be an effective and well-tolerated oral treatment for mild to moderate P. carinii pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L J Epstein
- Division of Pulmonary and Critical Care Medicine, Wilford Hall Medical Center, Lackland Air Force Base, San Antonio, Texas
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Araujo FG, Slifer T, Remington JS. Rifabutin is active in murine models of toxoplasmosis. Antimicrob Agents Chemother 1994; 38:570-5. [PMID: 8203856 PMCID: PMC284499 DOI: 10.1128/aac.38.3.570] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Rifabutin, a semisynthetic derivative of rifamycin S, was examined alone and in combination with other drugs for activity in treatment of systemic toxoplasmosis and toxoplasmic encephalitis in murine models. One hundred percent of the mice infected with a lethal inoculum of tachyzoites or cysts of Toxoplasma gondii were protected against death by treatment with doses of 400 or 300 mg of rifabutin per kg administered alone for 10 days. Doses of 200 mg/kg protected at least 80% of the mice, and doses of 100 mg/kg protected 10 to 40% of the infected mice against death. Doses of 50 mg/kg were not protective but caused a delay in time to death. Combination of nonprotective (50-mg/kg) or slightly protective (100-mg/kg) doses of rifabutin with doses of sulfadiazine, pyrimethamine, clindamycin, or atovaquone that did not confer any protection against death from toxoplasmosis when administered alone resulted in remarkable enhancement of the in vivo activities of all of these drugs. Seventy-five percent of the infected mice survived when treated with 100 mg of rifabutin per kg per day combined with the ineffective dose of 10 mg of pyrimethamine per kg. A dose of 50 mg of rifabutin per kg in combination with the ineffective dosages of clindamycin (25 mg/kg/day), atovoquone (5 mg/kg/day), and sulfadiazine (80 mg per liter of drinking water) protected at least 80, 60, and 60% of the mice against death, respectively. The inflammatory responses in the brains of mice treated for 30 days with 200 mg of rifabutin per kg per day were significantly reduced compared with those in the brains of untreated controls. These observations suggest that clinical trials with rifabutin for treatment and prevention of human toxoplasmosis may be justified, particularly when the drug is used in combination with other drugs with activity against T. gondii.
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Affiliation(s)
- F G Araujo
- Research Institute, Palo Alto Medical Foundation, California 94301
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27
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DeAngelis DV, Long JD, Kanics LL, Woolley JL. High-performance liquid chromatographic assay for the measurement of atovaquone in plasma. JOURNAL OF CHROMATOGRAPHY 1994; 652:211-9. [PMID: 8006106 DOI: 10.1016/0378-4347(93)e0387-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A rapid and efficient isocratic high-performance liquid chromatographic assay for the measurement of atovaquone in plasma has been developed and validated. The drug was extracted from plasma with organic solvents, assayed on a C1 column with a mobile phase of methanol-0.1% acetic acid (70:30, v/v), and detected by ultraviolet absorbance at 254 nm. Recovery of atovaquone from plasma was greater than 85%. Intra- and inter-assay variability were less than 8%, and the average accuracy of the assay (expressed as % bias) ranged from -7.4 to + 2.2%. The upper and lower limits of quantitation were 100 and 0.25 microgram/ml, respectively. Measurement of atovaquone in spiked plasma control samples during routine runs of clinical trial samples confirmed the reliability of the assay.
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Affiliation(s)
- D V DeAngelis
- Division of Pharmacokinetics and Drug Metabolism, Wellcome Research Laboratories, Research Triangle Park, NC 27709
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28
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Rolan PE, Mercer AJ, Weatherley BC, Holdich T, Meire H, Peck RW, Ridout G, Posner J. Examination of some factors responsible for a food-induced increase in absorption of atovaquone. Br J Clin Pharmacol 1994; 37:13-20. [PMID: 8148213 PMCID: PMC1364703 DOI: 10.1111/j.1365-2125.1994.tb04232.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
1. Atovaquone is a potent antiprotozoal slowly and irregularly absorbed after administration as tablets to fasting volunteers. A series of studies was performed to investigate the effects of food, bile and formulation on atovaquone absorption. 2. In 18 healthy male volunteers, a high-fat breakfast administered 45 min before 500 mg atovaquone as tablets increased AUC by 3.3-fold (95% CI 2.8-4.0) and Cmax 5.3-fold (4.3-6.6) compared with fasting. 3. The absorption of atovaquone from tablets was examined in 12 healthy male volunteers after an overnight fast, following toast alone, toast with 28 g butter (LOFAT), or toast with 56 g butter (HIFAT). Compared with absorption when fasted, toast had no significant effect but LOFAT increased AUC 3.0-fold (2.1-4.2) and Cmax 3.9-fold (2.6-5.8). HIFAT increased AUC 3.9-fold (2.7-5.5) and Cmax 5.6-fold (3.8-8.4). 4. The absorption of atovaquone was examined in nine healthy fasting male volunteers from tablets, an aqueous suspension, and an oily solution/suspension in miglyol (fractionated coconut oil). Compared with tablets, AUC following the aqueous suspension was increased 1.7-fold (1.0-2.7) and Cmax 2.4-fold (1.7-3.5). Following miglyol, AUC was increased to the same extent but Cmax was only increased 1.8-fold (1.2-2.6). 5. Atovaquone absorption was examined in eight healthy fasting male volunteers following an i.v. infusion of cholecystokinin octapeptide (CCK-OP) which decreased gallbladder volume by 82% (73%-90%) on occasion 1 or saline on occasion 2. AUC(0,12) was increased following CCK-OP by 1.6-fold (1.1-2.4) and Cmax by 1.5-fold (0.98-2.4).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P E Rolan
- Wellcome Research Laboratories, Beckenham, Kent
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Abstract
OBJECTIVE To review the chemistry, pharmacology, pharmacokinetics, clinical efficacy, and safety of atovaquone. DATA IDENTIFICATION An English-language literature search using MEDLINE (1984-1993), programs and abstracts of the 30th, 31st, and 32nd Interscience Conferences on Antimicrobial Agents and Chemotherapy, program and abstracts of the VIII International Conference on AIDS, and unpublished information from Burroughs Wellcome, the manufacturer of atovaquone. STUDY SELECTION All available pharmacokinetic and clinical trials were reviewed. DATA EXTRACTION Study quality was assessed by a critical appraisal of study design and methods. Pharmacokinetic studies were evaluated for sampling, methods used to determine pharmacokinetic properties, and the presence of concentration-response and concentration-toxicity relationships. Clinical trials were assessed primarily for comparative efficacy and toxicity. RESULTS Atovaquone is a novel hydroxynaphthoquinone with potent activity against Pneumocystis carinii and Toxoplasma gondii. Its pharmacokinetic properties are characterized by relatively poor bioavailability, excretion almost exclusively through the feces, lack of hepatic metabolism and urinary excretion, low steady-state plasma concentrations, high protein binding, and a long elimination half-life (50-70 h). Results from comparative clinical trials in AIDS patients with mild-to-moderate P. carinii pneumonia (PCP) reveal similar overall treatment success rates for atovaquone, trimethoprim/sulfamethoxazole (TMP/SMX), and pentamidine. Treatment failure because of lack of therapeutic response was significantly greater in patients who received atovaquone compared with those treated with TMP/SMX (p = 0.002). More atovaquone-patients experienced treatment failure compared with their pentamidine-treated counterparts, although statistical significance was not achieved. Treatment failure secondary to drug toxicity was significantly higher in the TMP/SMX- and pentamidine-treated patients (p < or = 0.01). Atovaquone has not been studied for PCP prophylaxis. Limited data exist on the use of atovaquone for toxoplasmic encephalitis (TE); however, results from an open trial reveal that the drug may be useful in treating this disorder. To date, atovaquone has been well tolerated by most patients administered the drug. The most common adverse effects include maculopapular rash, gastrointestinal disturbances, and fever. Atovaquone is considerably more costly than other oral agents used to treat PCP. CONCLUSIONS Atovaquone appears to be better tolerated but less effective than TMP/SMX and pentamidine in the treatment of mild-to-moderate PCP. There is not enough information available on the use of atovaquone for PCP prophylaxis or the treatment of TE to definitively describe its efficacy. Comparative clinical trials are needed to assess its role in this clinical setting.
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Affiliation(s)
- L G Haile
- Division of Clinical Pharmacy, School of Pharmacy, University of California, San Francisco 94143
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Romand S, Pudney M, Derouin F. In vitro and in vivo activities of the hydroxynaphthoquinone atovaquone alone or combined with pyrimethamine, sulfadiazine, clarithromycin, or minocycline against Toxoplasma gondii. Antimicrob Agents Chemother 1993; 37:2371-8. [PMID: 8285620 PMCID: PMC192394 DOI: 10.1128/aac.37.11.2371] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The efficacy of atovaquone alone or combined with pyrimethamine, sulfadiazine, clarithromycin, and minocycline was examined in vitro and in a murine model of acute toxoplasmosis. In vitro studies were performed with MRC5 fibroblast tissue cultures, with quantification of Toxoplasma growth by an enzyme-linked immunosorbent assay. For in vivo studies, mice were acutely infected intraperitoneally with 10(4) tachyzoites of the virulent RH strain and then treated perorally for 10 days from day 1 postinfection. The following drug regimens were investigated: atovaquone at 100 and 50 mg/kg of body weight per day and the combinations of atovaquone at 50 mg/kg with sulfadiazine at 200 mg/kg, pyrimethamine at 12.5 mg/kg, clarithromycin at 200 mg/kg, or minocycline at 50 mg/kg. Efficacy was assessed by determination of survival rates and sequential determination of parasite burdens in blood, brain, and lungs. In vitro, atovaquone inhibited Toxoplasma growth at a concentration of > or = 0.02 mg/liter; the 50% inhibitory concentration was estimated to be 0.023 mg/liter. No synergistic effect was observed when it was combined with sulfadiazine, clarithromycin, or minocycline, whereas a significant antagonistic effect was noted for the combination of atovaquone with pyrimethamine. In vivo, administration of atovaquone at 100 or 50 mg/kg/day for 10 days resulted in prolonged survival compared with that in untreated mice; this survival was associated with a reduction of parasite burdens in blood and tissues during the course of treatment. The combinations of atovaquone with pyrimethamine, clarithromycin, or sulfadiazine were more efficient than each drug administered alone, in terms of survival, but parasite burdens in blood and organs were not reduced compared with those in mice treated with any of the agents alone. These experimental results confirmed the activity of atovaquone against Toxoplasma gondii, but no marked improvement in efficacy was observed in vitro and in vivo when this drug was combined with pyrimethamine, sulfadiazine, minocycline, or clarithromycin.
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Affiliation(s)
- S Romand
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Paris, France
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DeMuria D, Forrest A, Rich J, Scavone JM, Cohen LG, Kazanjian PH. Pharmacokinetics and bioavailability of fluconazole in patients with AIDS. Antimicrob Agents Chemother 1993; 37:2187-92. [PMID: 8257143 PMCID: PMC192248 DOI: 10.1128/aac.37.10.2187] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Fluconazole pharmacokinetics were evaluated for 10 volunteers with AIDS who had no clinical evidence of gastroenteritis. Single 100-mg intravenous (i.v.) and oral (p.o.) doses were administered in a randomized, crossover design. i.v. doses were delivered by a constant-rate infusion over 30 min. Serum fluconazole concentrations were measured by gas-liquid chromatography. The i.v. and p.o. studies were modelled simultaneously by iterative two-stage analysis, which provided individual parameter estimates and a population pharmacokinetic model. Median areas under the concentration-time curves for i.v. and p.o. studies did not differ (90.6 and 99.3 micrograms/ml.h, respectively). Consistent with this finding, the median fractional bioavailability was 1.1 (range, 0.45 to 1.3), comparable to those in healthy subjects. Serum pharmacokinetics in these AIDS patients were generally similar to published data for healthy volunteers. However, following p.o. dosing, we observed a slightly delayed and highly variable time to maximum concentration in serum (median, 2 h; range, 15 min to 8 h). Data were well described by a linear, two-compartment pharmacokinetic model with first-order absorption and elimination. Repeated-measures analysis of variance found no significant differences among any of the pharmacokinetic parameters between i.v. and p.o. studies. On the basis of our findings, we suggest no change in dosage of p.o. fluconazole in patients with AIDS who show no clinical signs of enteropathy.
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Affiliation(s)
- D DeMuria
- Clinical Pharmacokinetics Laboratory, Millard Fillmore Hospital, Buffalo, New York 14209
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II — Prophylaxie de la toxoplasmose : bases expérimentales. Med Mal Infect 1993. [DOI: 10.1016/s0399-077x(05)80664-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
Concern has been arisen about the recently reported increasing incidence of PCP in patients with cancer and the potential transmissibility of this infection. Whether or not there is an increase in the incidence of P. carinii infections, PCP should be considered in the differential diagnosis of pulmonary infiltrates in bone marrow transplant recipients, in patients with hematologic neoplasms and in patients with primary or metastatic brain neoplasms. Intensity of immunosuppression plays a crucial role, especially long-term (> 2 months) corticosteroid treatment. PCP is usually manifested clinically during augmentation or during tapering of corticosteroid dose. Thus, if the chest radiograph of a high-risk patient shows diffuse infiltrates, bronchoscopy and bronchoalveolar lavage should be done immediately. Treatment options are the same as for the AIDS population, except that TMP-SMX is tolerated better in non-AIDS patients. The role of supportive care, including mechanical ventilation in such patients should not be underestimated. Oral therapy with dapsone-trimethoprim or with atovaquone, can be as effective as conventional therapy in mild disease, permitting treatment on an outpatient basis. PCP is often preventable and our understanding has improved about when prophylaxis should be initiated. In the future, the emergence of new technologies for diagnosis and of new agents for treatment and prophylaxis, will bring us closer to the goal of controlling this serious infection.
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Hughes W, Leoung G, Kramer F, Bozzette SA, Safrin S, Frame P, Clumeck N, Masur H, Lancaster D, Chan C. Comparison of atovaquone (566C80) with trimethoprim-sulfamethoxazole to treat Pneumocystis carinii pneumonia in patients with AIDS. N Engl J Med 1993; 328:1521-7. [PMID: 8479489 DOI: 10.1056/nejm199305273282103] [Citation(s) in RCA: 168] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Both trimethoprim-sulfamethoxazole and pentamidine are effective as treatments for Pneumocystis carinii pneumonia, but adverse effects frequently limit their use. Atovaquone (566C80) is a new hydroxynaphthoquinone with activity against P. carinii. METHODS We conducted a double-blind, multicenter study in patients with the acquired immunodeficiency syndrome and mild or moderately severe P. carinii pneumonia. They were randomly assigned to 21 days of orally administered treatment three times daily with either atovaquone (750 mg) or trimethoprim (320 mg) plus sulfamethoxazole (1600 mg). RESULTS Of the 322 patients with histologically confirmed P. carinii pneumonia, 160 received atovaquone and 162 received trimethoprim-sulfamethoxazole. Of those who could be evaluated for therapeutic efficacy, 28 of 138 patients given atovaquone (20 percent) and 10 of 146 patients given trimethoprim-sulfamethoxazole (7 percent) did not respond (P = 0.002). Treatment-limiting adverse effects required a change of therapy in 11 patients in the atovaquone group (7 percent) and 33 patients in the trimethoprim-sulfamethoxazole group (20 percent) (P = 0.001). Therapy involving only the initial drug was successful and free of adverse effects in 62 percent of those assigned to atovaquone and 64 percent of those assigned to trimethoprim-sulfamethoxazole. Within four weeks of the completion of treatment, there were 11 deaths in the atovaquone group (4 due to P. carinii pneumonia) and 1 death in the trimethoprim-sulfamethoxazole group (P = 0.003). Diarrhea at entry was associated with lower plasma drug concentrations (P = 0.009), therapeutic failure (P < 0.001), and death (P < 0.001) in the atovaquone group but not in the trimethoprim-sulfamethoxazole group. CONCLUSIONS For the treatment of P. carinii pneumonia, atovaquone is less effective than trimethoprim-sulfamethoxazole, but it has fewer treatment-limiting adverse effects.
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Affiliation(s)
- W Hughes
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tenn. 38105
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Abstract
Atovoquone is a novel hydroxynaphthoquinone that is currently showing clinical promise for the treatment of malaria and the AIDS-associated diseases Pneumocystis carinii pneumonia and toxoplosmosis. The drug is the end product of half a century of research by numerous groups who have investigated the ontiporositic properties of many related compounds. Atovaquone is the only member of the series to show therapeutic activity in humans when taken orally. In this article, Alan Hudson explores the background to the discovery of this drug and reviews its mode of action, and biological and clinical profiles.
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Affiliation(s)
- A T Hudson
- Research Laboratories, Langley Court, Beckenham, UK BR3 3BS
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Abstract
Great strides have been made in the therapy of human immunodeficiency virus (HIV) infection. Currently approved drugs include zidovudine and didanosine. A third drug, dideoxycytidine (zalcitibine), has recently been filed for approval with the Food and Drug Administration. All these drugs work through inhibition of the reverse transcriptase enzyme. Zidovudine is the only drug that has shown clinical efficacy against HIV. Treatment of patients with advanced HIV disease (i.e., acquired immune deficiency syndrome [AIDS] or symptomatic infection with < 200 CD4+ lymphocytes per mm3), results in a prolongation and improved quality of life. Zidovudine is the only antiretroviral agent approved for the treatment of asymptomatic patients. Early intervention with zidovudine has been shown to delay progression to AIDS when patients' CD4+ lymphocyte counts decline to less than 500/mm3, irrespective of clinical signs or symptoms of HIV infection. Didanosine is currently indicated for the treatment of patients with advanced HIV disease who are intolerant to or failing zidovudine therapy. The major toxicity of zidovudine is bone marrow suppression with anemia and granulocytopenia (which occurs in from 1% to 45% of patients, depending on the clinical stage of disease and the dose of the drug). Didanosine and zalcitibine have both been associated with a severe peripheral neuropathy, which is generally reversible on cessation of the drug. In addition, didanosine has been implicated as a cause of pancreatitis that has been fatal in a small percentage of cases. The toxicities of didanosine and zalcitibine range from 1% to 10%, depending on dose, duration of therapy, and the presence of underlying HIV-related peripheral neuropathy or a previous history of pancreatitis. The clinical hallmark of HIV infection is the development of opportunistic infections and malignancies, which are a consequence of the profound immunodeficiency. The risk of an opportunistic infection increases significantly as the T-helper lymphocyte count declines to less than 20%, or 200 to 250/mm3. The spectrum of opportunistic infections ranges from viruses to protozoa. Patients with advanced HIV disease are also at increased risk of infection with nonopportunistic, community-acquired pathogens. Primary and secondary prophylaxis against the most common AIDS-defining opportunistic infection, Pneumocystis carinii pneumonia, is now recommended. Studies are currently underway to determine the efficacy of prophylaxis against other opportunistic pathogens. Treatment of opportunistic infections associated with AIDS has improved significantly over the past 5 years as new drugs and combination regimens of antimicrobials have been developed.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- H A Kessler
- Section of Infectious Disease, Rush Medical College, Chicago, Illinois
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37
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Paar D, Masur H. Advances in the Management of Major Opportunistic Infections in Patients with Human Immunodeficiency Virus Infection. J Pharm Pract 1992. [DOI: 10.1177/089719009200500306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- David Paar
- Critical Care Medicine, National Institutes of Health, Building 10, Room 10D48, Bethesda, MD 20892
| | - Henry Masur
- Critical Care Medicine, National Institutes of Health, Building 10, Room 10D48, Bethesda, MD 20892
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Lopez JS, de Smet MD, Masur H, Mueller BU, Pizzo PA, Nussenblatt RB. Orally administered 566C80 for treatment of ocular toxoplasmosis in a patient with the acquired immunodeficiency syndrome. Am J Ophthalmol 1992; 113:331-3. [PMID: 1543229 DOI: 10.1016/s0002-9394(14)71588-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Araujo FG, Huskinson-Mark J, Gutteridge WE, Remington JS. In vitro and in vivo activities of the hydroxynaphthoquinone 566C80 against the cyst form of Toxoplasma gondii. Antimicrob Agents Chemother 1992; 36:326-30. [PMID: 1605598 PMCID: PMC188436 DOI: 10.1128/aac.36.2.326] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The in vitro and in vivo activities of the hydroxynaphthoquinone 566C80 against the cyst form of Toxoplasma gondii were evaluated. In vitro treatment (100 micrograms of 566C80 per ml for 3 days) of cysts isolated from brains of mice infected for 1, 2, 3, 4, or 9 months resulted in loss of viability of the cysts and did not reveal any influence of the duration of in vivo infection on sensitivity to the drug. In vivo experiments to determine the effect of prolonged treatment with 200 mg of 566C80 per kg of body weight per day on cysts in brains of CBA/Ca mice infected with strain ME49 revealed a steady and significant decline in the numbers of cysts compared with the numbers in untreated controls. Histopathology of brains from control mice revealed inflammatory infiltrates around capillaries and in the parenchymas and meninges which were consistently less evident in the brains of treated mice. In addition, cysts were rarely observed in treated mice, whereas extensive inflammation and large numbers of cysts were found throughout the entire brain in control mice infected for the same period. The reduction in the numbers of cysts was evident as early as day 5 of treatment but was more marked at 8 weeks of treatment. The numbers of cysts in the brains of Swiss Webster mice infected for 3 or 6 months also significantly decreased following treatment for 15 or 30 days with the same dose of 566C80. Our results indicate that 566C80 has excellent activity against cysts of T. gondii both in vivo and in vitro and that sensitivity of the cysts to 566C80 is not affected by the duration of the infection in vivo.
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Affiliation(s)
- F G Araujo
- Department of Immunology and Infectious Diseases, Palo Alto Medical Foundation, California 94301, USA
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41
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Affiliation(s)
- P A Pizzo
- Pediatric Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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42
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Falloon J, Kovacs J, Hughes W, O'Neill D, Polis M, Davey RT, Rogers M, LaFon S, Feuerstein I, Lancaster D. A preliminary evaluation of 566C80 for the treatment of Pneumocystis pneumonia in patients with the acquired immunodeficiency syndrome. N Engl J Med 1991; 325:1534-8. [PMID: 1944437 DOI: 10.1056/nejm199111283252202] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND The drug 566C80 is an investigational hydroxynaphthoquinone that is active against Pneumocystis carinii in vitro and in animal models. Initial studies in humans indicate that 566C80 is safe and has adequate bioavailability after oral administration. METHODS We conducted an open-label trial of 566C80 in 34 adults with the acquired immunodeficiency syndrome (AIDS) and untreated pneumocystis pneumonia. All the patients had a partial pressure of arterial oxygen of at least 60 mm Hg while breathing room air. They were enrolled sequentially in three cohorts taking 566C80 at different dosages, all administered orally: 750 mg three times daily for 5 days, then twice daily for 16 days; 750 mg three times daily for 21 days; and 750 mg four times daily for 21 days. RESULTS All 34 patients survived, and 27 (79 percent) were successfully treated with 566C80 alone. The mean partial pressure of oxygen in 33 patients was 78 mm Hg at entry and 93 mm Hg after the course of 566C80 (P less than 0.001). In five patients (15 percent) the drug was discontinued because of lack of response. In four patients (12 percent), the drug was discontinued because of toxicity (fever and rash in two patients each). In two of these, treatment was considered to have succeeded because 566C80 was not discontinued because of toxicity until after day 14. Five of the successfully treated patients had rashes that resolved despite continued therapy. In nine patients, serum alanine aminotransferase levels rose above 100 U per liter. During the first three months after the completion of therapy, pneumocystis pneumonia recurred in 4 of the 27 successfully treated patients, and another 3 patients had recurrences between month 3 and month 6 of follow-up. The mean (+/- SEM) steady-state plasma levels of 566C80 were similar in the three cohorts: 16.3 +/- 2.10, 20.4 +/- 2.48, and 18.9 +/- 3.08 micrograms per milliliter in the patients taking the drug twice daily, three times daily, and four times daily, respectively. CONCLUSIONS From these preliminary data, the investigational compound 566C80 appears to be a safe, effective, and well-tolerated therapy for P. carinii pneumonia of mild-to-moderate severity in patients with AIDS.
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Affiliation(s)
- J Falloon
- Department of Critical Care Medicine, National Institutes of Health, Bethesda, MD 20892
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Pizzo PA, Rubin M, Freifeld A, Walsh TJ. The child with cancer and infection. I. Empiric therapy for fever and neutropenia, and preventive strategies. J Pediatr 1991; 119:679-94. [PMID: 1941374 DOI: 10.1016/s0022-3476(05)80281-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- P A Pizzo
- Pediatric Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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