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Brand NR, Opoka RO, Hamre KES, John CC. Differing Causes of Lactic Acidosis and Deep Breathing in Cerebral Malaria and Severe Malarial Anemia May Explain Differences in Acidosis-Related Mortality. PLoS One 2016; 11:e0163728. [PMID: 27684745 PMCID: PMC5042445 DOI: 10.1371/journal.pone.0163728] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 09/13/2016] [Indexed: 12/04/2022] Open
Abstract
Lactic acidosis (LA) is a marker for mortality in severe malaria, but the mechanisms that lead to LA in the different types of severe malaria and the extent to which LA-associated mortality differs by type of severe malaria are not well described. We assessed the frequency of LA in children admitted to Mulago Hospital, Kampala, Uganda with cerebral malaria (CM, n = 193) or severe malarial anemia (SMA, n = 216). LA was compared to mortality and measures of parasite biomass and sequestration (P. falciparum histidine-rich protein-2 (PfHRP2) concentration, platelet count), and to a measure of systemic tissue oxygen delivery (hemoglobin level). LA was more frequent in children with SMA than CM (SMA, 47.7%, CM, 34.2%, P = 0.006), but mortality was higher in children with CM (13.0%) than SMA (0.5%, P<0.0001). In CM, LA was associated with increased PfHRP2 concentration and decreased platelet count but was not associated with hemoglobin level. In contrast, in SMA, LA was associated with a decreased hemoglobin level, but was not associated with PfHRP2 concentration or platelet count. LA was related to mortality only in CM. In multivariable regression analysis of the effect PfHRP2 and hemoglobin levels on LA and DB, only PfHRP2 level increased risk of LA and DB in CM, while in SMA, elevated hemoglobin strongly decreased risk of LA and DB, and PfHRP2 level modestly increased risk of LA. The study findings suggest that LA in CM is due primarily to parasite sequestration, which currently has no effective adjunctive therapy, while LA in SMA is due primarily to anemia, which is rapidly corrected with blood transfusion. Differing etiologies of LA in CM and SMA may explain why LA is associated with mortality in CM but not SMA.
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Affiliation(s)
- Nathan R. Brand
- Columbia University College of Physicians and Surgeons, School of Medicine, New York, New York, United States of America
| | - Robert O. Opoka
- Makerere University, Department of Pediatrics, Kampala, Uganda
| | - Karen E. S. Hamre
- University of Minnesota, Department of Pediatrics, Minneapolis, Minnesota, United States of America
| | - Chandy C. John
- Indiana University, Department of Pediatrics, Indianapolis, Indiana, United States of America
- * E-mail:
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Quantitative analysis of drug effects at the whole-body level: a case study for glucose metabolism in malaria patients. Biochem Soc Trans 2015; 43:1157-63. [PMID: 26614654 DOI: 10.1042/bst20150145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We propose a hierarchical modelling approach to construct models for disease states at the whole-body level. Such models can simulate effects of drug-induced inhibition of reaction steps on the whole-body physiology. We illustrate the approach for glucose metabolism in malaria patients, by merging two detailed kinetic models for glucose metabolism in the parasite Plasmodium falciparum and the human red blood cell with a coarse-grained model for whole-body glucose metabolism. In addition we use a genome-scale metabolic model for the parasite to predict amino acid production profiles by the malaria parasite that can be used as a complex biomarker.
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Metabolic modulation of cancer: a new frontier with great translational potential. J Mol Med (Berl) 2015; 93:127-42. [DOI: 10.1007/s00109-014-1250-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/25/2014] [Accepted: 12/15/2014] [Indexed: 12/22/2022]
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Planche T. Malaria and fluids – balancing acts. Trends Parasitol 2005; 21:562-7. [PMID: 16236551 DOI: 10.1016/j.pt.2005.09.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 08/10/2005] [Accepted: 09/29/2005] [Indexed: 11/28/2022]
Abstract
Severe malaria has many manifestations, of which coma and lactic acidosis are the best independent predictors of a fatal outcome. Most deaths from malaria occur within the first 24 h of admission, despite appropriate antimalarial chemotherapy. Adjunctive therapy for severe malaria has been seen as a way to improve survival by 'buying time' until antimalarials can act. Several adjunctive therapies have undergone clinical trials in the past 25 years but all of these trials showed worsened outcome or no benefit to patients receiving adjuncts compared with those receiving placebo. Although metabolic acidosis occurs in both hypovolaemia and malaria, the contribution of the former to the pathophysiology of severe malaria is unclear. I suggest that lactic acidosis due to malaria can be explained primarily by factors that are independent of volume depletion. Lactic acidosis in malaria can be treated safely with dichloroacetate. This intervention could prove useful as an adjunctive therapy aimed at reducing mortality rates in severe malaria.
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Affiliation(s)
- Tim Planche
- Department of Cellular and Molecular Medicine, Infectious Diseases, St George's Hospital Medical School, London, UK, SW17 0RE.
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Planche T, Krishna S. The relevance of malaria pathophysiology to strategies of clinical management. Curr Opin Infect Dis 2005; 18:369-75. [PMID: 16148522 DOI: 10.1097/01.qco.0000180161.38530.81] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW Malaria claims 1-2 million lives a year, mostly children in sub-Saharan Africa. The majority of hospital deaths occur within 24 h of admission despite adequate treatment with antimalarial chemotherapy. Understanding the pathophysiological disturbances of malaria should allow the development of supportive therapy to "buy time" for antimalarial chemotherapy to clear the infection. It is sobering, however, that despite many trials over the last quarter of a century all large trials of adjunctive therapy so far have resulted in either increased morbidity or mortality, or both. RECENT FINDINGS Severe malaria may be divided broadly into neurological and metabolic complications. We review recent findings about the pathophysiology of these complications and the implications for future adjunctive therapy of malaria, including the proposed importance of fluid volume depletion and sequestration of parasitized red cells in severe malaria. We also consider other anaemia, hyperparasitaemia and renal failure, which also require urgent treatment in severe malaria. SUMMARY We review the important pathophysiological features of severe malaria and promising adjunctive therapies such as dichloroacetate that warrant further larger trials to determine whether they improve the so-far intractable death rate of severe malaria.
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Affiliation(s)
- Tim Planche
- Department of Cellular and Molecular Medicine, Centre for Infection, St. George's Hospital Medical School, London SW17 0RE, UK.
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Planche T, Dzeing A, Ngou-Milama E, Kombila M, Stacpoole PW. Metabolic complications of severe malaria. Curr Top Microbiol Immunol 2005; 295:105-36. [PMID: 16265889 DOI: 10.1007/3-540-29088-5_5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Metabolic complications of malaria are increasingly recognized as contributing to severe and fatal malaria. Disorders of carbohydrate metabolism, including hypoglycaemia and lactic acidosis, are amongst the most important markers of disease severity both in adults and children infected with Plasmodium falciparum. Amino acid and lipid metabolism are also altered by malaria. In adults, hypoglycaemia is associated with increased glucose turnover and quinine-induced hyperinsulinaemia, which causes increased peripheral uptake of glucose. Hypoglycaemia in children results from a combination of decreased production and/or increased peripheral uptake of glucose, due to increased anaerobic glycolysis. Patients with severe malaria should be monitored frequently for hypoglycaemia and treated rapidly with intravenous glucose if hypoglycaemia is detected. The most common aetiology of hyperlactataemia in severe malaria is probably increased anaerobic glucose metabolism, caused by generalized microvascular sequestration of parasitized erythrocytes that reduces blood flow to tissues. Several potential treatments for hyperlactataemia have been investigated, but their effect on mortality from severe malaria has not been determined.
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Affiliation(s)
- T Planche
- Division of Cellular and Molecular Medicine, Centre for Infection, St. George's University of London, Cranmer Terrace, London SW17 ORE, UK.
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Agbenyega T, Planche T, Bedu-Addo G, Ansong D, Owusu-Ofori A, Bhattaram VA, Nagaraja NV, Shroads AL, Henderson GN, Hutson AD, Derendorf H, Krishna S, Stacpoole PW. Population kinetics, efficacy, and safety of dichloroacetate for lactic acidosis due to severe malaria in children. J Clin Pharmacol 2003; 43:386-96. [PMID: 12723459 DOI: 10.1177/0091270003251392] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The authors conducted a randomized, double-blind, placebo-controlled trial of intravenous dichloroacetate (DCA) for the purpose of treating lactic acidosis in 124 West African children with severe Plasmodium falciparum malaria. Lactic acidosis independently predicts mortality in severe malaria, and DCA stimulates the oxidative removal of lactate in vivo. A single infusion of 50 mg/kg DCA was well tolerated. When administered at the same time as a dose of intravenous quinine, DCA significantly increased the initial rate and magnitude of fall in blood lactate levels and did not interfere with the plasma kinetics of quinine. The authors developed a novel population pharmacokinetic-pharmacodynamic indirect-response model for DCA that incorporated characteristics associated with disease reversal. The model describes the complex relationships among antimalarial treatment procedures, plasma DCA concentrations, and the drug's lactate-lowering effect. DCA significantly reduces the concentration of blood lactate, an independent predictor of mortality in malaria. Its prospective evaluation in affecting mortality in this disorder appears warranted.
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MESH Headings
- Acidosis, Lactic/drug therapy
- Acidosis, Lactic/etiology
- Acidosis, Lactic/metabolism
- Antimalarials/therapeutic use
- Child, Preschool
- Dichloroacetic Acid/adverse effects
- Dichloroacetic Acid/pharmacokinetics
- Dichloroacetic Acid/therapeutic use
- Double-Blind Method
- Drug Interactions
- Drug Therapy, Combination
- Female
- Humans
- Injections, Intramuscular
- Malaria, Falciparum/complications
- Malaria, Falciparum/drug therapy
- Malaria, Falciparum/metabolism
- Male
- Models, Biological
- Quinine/blood
- Quinine/therapeutic use
- Time Factors
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Affiliation(s)
- Tsiri Agbenyega
- Department of Physiology, University of Science and Technology, School of Medical Sciences, Departments of Child Health and Medicine, Komfo-Anokye Teaching Hospital, Kumasi, Ghana
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Fox AW, Turkel CC, Buffini JD. Nutritional lactate spikes: quantitative antagonism by dichloroacetate. Nutr Res 2001. [DOI: 10.1016/s0271-5317(01)00339-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Krishna S, Nagaraja NV, Planche T, Agbenyega T, Bedo-Addo G, Ansong D, Owusu-Ofori A, Shroads AL, Henderson G, Hutson A, Derendorf H, Stacpoole PW. Population pharmacokinetics of intramuscular quinine in children with severe malaria. Antimicrob Agents Chemother 2001; 45:1803-9. [PMID: 11353629 PMCID: PMC90549 DOI: 10.1128/aac.45.6.1803-1809.2001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2000] [Accepted: 03/13/2001] [Indexed: 11/20/2022] Open
Abstract
We present the first population pharmacokinetic analysis of quinine in patients with Plasmodium falciparum malaria. Ghanaian children (n = 120; aged 12 months to 10 years) with severe malaria received an intramuscular loading dose of quinine dihydrochloride (20 mg/kg of body weight). A two-compartment model with first-order absorption and elimination gave post hoc estimates for pharmacokinetic parameters that were consistent with those derived from non-population pharmacokinetic studies (clearance [CL] = 0.05 liter/h/kg of body weight; volume of distribution in the central compartment [V(1)] = 0.65 liter/kg; volume of distribution at steady state = 1.41 liter/kg; half-life at beta phase = 19.9 h). There were no covariates (including age, gender, acidemia, anemia, coma, parasitemia, or anticonvulsant use) that explained interpatient variability in weight-normalized CL and V(1). Intramuscular quinine was associated with minor, local toxicity in some patients (13 of 108; 12%), and 11 patients (10%) experienced one or more episodes of postadmission hypoglycemia. A loading dose of intramuscular quinine results in predictable population pharmacokinetic profiles in children with severe malaria and may be preferred to the intravenous route of administration in some circumstances.
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Affiliation(s)
- S Krishna
- Department of Infectious Diseases, St. George's Hospital Medical School, Cranmer Terrace, London SW17 ORE, United Kingdom.
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Stacpoole PW, Barnes CL, Hurbanis MD, Cannon SL, Kerr DS. Treatment of congenital lactic acidosis with dichloroacetate. Arch Dis Child 1997; 77:535-41. [PMID: 9496194 PMCID: PMC1717417 DOI: 10.1136/adc.77.6.535] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- P W Stacpoole
- Department of Medicine (Division of Endocrinology and Metabolism), University of Florida, College of Medicine, Gainesville, USA
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Krishna S, Supanaranond W, Pukrittayakamee S, Kuile FT, Ruprah M, White NJ. The disposition and effects of two doses of dichloroacetate in adults with severe falciparum malaria. Br J Clin Pharmacol 1996; 41:29-34. [PMID: 8824690 DOI: 10.1111/j.1365-2125.1996.tb00155.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
1 Dichloroacetate (DCA) is a promising treatment for lactic acidosis complicating severe malaria. The pharmacokinetics, pharmacodynamics and toxicity of dichloroacetate were evaluated in 11 patients with severe malaria, and their lactate responses compared with nine control patients in an open-label prospective study. 2 Intravenous DCA (46 mg kg-1 infused in 30 min) or saline placebo was given on admission to the study, and 12 h later, as an adjunct to standard quinine treatment. 3 An open one-compartment model with the following parameters described the pharmacokinetics of DCA after one dose (mean [s.d.]): V = 0.44(0.2) 1 kg-1; CL = 0.13 [0.027] 1 h-1 kg-1; Cmax = 106[28] mg1-1; t1/2 = 3.4(2.2) h. After two doses of DCA (n = 9) the pharmacokinetic parameters were similar to those after the first dose. 4 DCA decreased venous plasma lactate concentrations by 42% of baseline values 8 h after admission, normalized arterial pH from a mean(s.d.) of 7.367(0.063) to 7.39(0.1), and decreased the calculated base deficit from 9.2(7.3) mEq 1-1 to 6.4(10.4) mEq 1-1. In control patients lactate concentrations fell by approximately 14% of baseline concentrations (P < 0.02 compared with DCA recipients). Venous lactate concentrations fell a further 16% from baseline values after the second dose of DCA but this change was not significantly different from controls. There was no electrocardiographic or other evidence of toxicity associated with DCA. 5 These data suggest that a single intravenous infusion of DCA rapidly reduces hyperlactataemia in patients severely ill with malaria, and that DCA should be evaluated further as an adjunct to conventional antimalarial and supportive measures for such patients with lactic acidosis.
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Affiliation(s)
- S Krishna
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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