Antimalarial treatment in infants

INTRODUCTION

Malaria in infants is common in high-transmission settings, especially in infants >6 months. Infants undergo physiological changes impacting pharmacokinetics and pharmacodynamics of anti-malarial drugs and, consequently, the safety and efficacy of malaria treatment. Yet, treatment guidelines and evidence on pharmacological interventions for malaria often fail to address this vulnerable age-group. This review aims to summarise the available data on anti-malarial treatment in infants.

AREAS COVERED

The standard recommended treatments for severe and uncomplicated malaria are generally safe and effective in infants. However, infants have an increased risk of drug-related vomiting and have distinct pharmacokinetic parameters of antimalarials compared with older patients. These include larger volumes of distribution, higher clearance rates and immature enzyme systems. Consequently, infants with malaria may be at increased risk of treatment failure and drug toxicity.

EXPERT OPINION

Knowledge expansion to optimize treatment can be achieved by including more infants in antimalarial drug trials and by reporting separately on treatment outcomes in infants. Additional evidence on the efficacy, safety, tolerability, acceptability and effectiveness of ACTs in infants is needed, as well as population pharmacokinetics studies on antimalarials in the infant population.

The preclinical discovery and development of rectal artesunate for the treatment of malaria in young children: a review of the evidence

INTRODUCTION

Plasmodium falciparum, the deadliest malaria parasite, kills hundreds of thousands of people per year, mainly young children in Sub-Saharan Africa. Artesunate suppositories are recommended as pre-referral malaria treatment in remote endemic areas for severely ill children to prevent progression of the disease and to provide extra time for patients until the definitive severe malaria treatment can be administered.

AREAS COVERED

The authors provide an overview of the discovery of artesunate and its different formulations focusing on rectal administration, summarizing key studies concerning the pharmacokinetic, pharmacodynamic, safety, tolerability and efficacy of rectal artesunate leading to WHO recommendation and market authorization in Africa. In addition, studies on acceptance and adherence to rectal artesunate administration and the post-launch status are also covered.

EXPERT OPINION

Efforts by ministries of health in malaria endemic countries together with international health organizations should establish and enforce guidelines to ensure the correct use of artesunate suppositories only as pre-referral medication in presumed severe malaria cases to minimize the risk of abuse as a monotherapy for treatment of uncomplicated malaria. The priority is to not jeopardize the efficacy of artesunate and to prevent resistance development against this valuable drug class in Africa.

Use of post-graduate students' research in evidence informed health policies: a case study of Makerere University College of Health Sciences, Uganda

BACKGROUND

World over, stakeholders are increasingly concerned about making research useful in public policy-making. However, there are hardly any reports linking production of research by students at institutions of higher learning to its application in society. We assessed whether and how post-graduate students' research was used in evidence-informed health policies.

METHODS

This is a multiple case study of master's students' dissertations at Makerere University College of Health Sciences (MakCHS) produced between 1996 and 2010. In a structured review, we applied a theoretical framework of 'research use' and used content analysis to map how research was used in public policy documents. We categorised content of these documents according to the health-related Millennium Development Goals (MDG). We defined a case of 'use' as citation of research products from a master's student's dissertation in a public policy-related document.

RESULTS

We found 22 cases of research use in policy-related documents (0.5%) out of a total 4230 citations from 16 of 1172 total dissertations (1.4%). Additionally, research was mostly cited in primary studies (95.4%), systematic reviews (3%), narrative reviews (0.8%) and cost-effectiveness analyses (0.2%). Research was predominantly used instrumentally, to either frame the problem (burden of disease or health condition) or select an intervention (treatment or diagnostic option) and rarely symbolically to justify strategies already selected. The bulk of the cases of research use addressed child health (MDG 4), focusing on infectious diseases (MDG 6), mainly in international clinical or public health guidelines, working papers, a consensus statement and a global report. We distilled 'synergistic relationships' among organisations or interest groups, 'globalisation of local evidence', 'trade-offs' in the use of research and use of 'negative results' from the documents and text content.

CONCLUSIONS

Research from dissertations of post-graduate students at MakCHS is used in evidence-informed health policies, particularly for infectious diseases in child health. Further, we have delineated pathways of research use in the global arena and highlighted the importance of 'negative results' from dissertations of post-graduate students at MakCHS.

Rectal route in the 21st Century to treat children

The rectal route can be considered a good alternative to the oral route for the paediatric population because these dosage forms are neither to be swallowed nor need to be taste-masked. Rectal forms can also be administered in an emergency to unconscious or vomiting children. Their manufacturing cost is low with excipients generally regarded as safe. Some new formulation strategies, including mucoadhesive gels and suppositories, were introduced to increase patient acceptability. Even if recent paediatric clinical studies have demonstrated the equivalence of the rectal route with others, in order to enable the use of this promising route for the treatment of children in the 21st Century, some effort should be focused on informing and educating parents and care givers. This review is the first ever to address all the aforementioned items, and to list all drugs used in paediatric rectal forms in literature and marketed products in developed countries.

Clinical features and outcome in children with severe Plasmodium falciparum malaria: a meta-analysis

Background

Although global malaria mortality is declining, estimates may not reflect better inpatient management of severe malaria (SM) where reported case fatality rates (CFRs) vary from 1–25%.

Methods

A meta-analysis of prospective studies of SM was conducted to examine i) whether hypothesized differences between clinical features and outcome in Melanesian compared with African or Asian children really exist, and ii) to explore temporal changes in overall and complication-specific CFRs. The proportions of different SM complications and, overall and complication-specific CFRs were incorporated into the meta-analysis. Adjustments were made for study-level covariates including geographic region, SM definition, artemisinin treatment, median age of participants and time period.

Findings

Sixty-five studies were included. Substantial heterogeneity (I²>80%) was demonstrated for most outcomes. SM definition contributed to between-study heterogeneity in proportions of cerebral malaria (CM), metabolic acidosis (MA), severe anemia and overall CFR, whilst geographic region was a significant moderator in for CM and hypoglycemia (HG) rates. Compared with their African counterparts, Melanesian children had lower rates of HG (10% [CI95 7–13%] versus 1% [0–3%], P<0.05), lower overall CFR (2% [0–4%] versus 7% [6–9%], P<0.05) and lower CM-specific CFR (8% [0–17%] versus 19% [16–21%], P<0.05). There was no temporal trend for overall CFR and CM-specific CFR but declining HG- and MA- specific CFRs were observed.

Interpretation

These data highlight that recent estimates of declining global malaria mortality are not replicated by improved outcomes for children hospitalized with SM. Significant geographic differences in the complication rates and subsequent CFRs exist and provide the first robust confirmation of lower CFRs in Melanesian children, perhaps due to less frequent HG.

Malaria in Uganda: challenges to control on the long road to elimination: I. Epidemiology and current control efforts

Malaria remains one of the leading health problems of the developing world, and Uganda bears a particularly large burden from the disease. Our understanding is limited by a lack of reliable data, but it is clear that the prevalence of malaria infection, incidence of disease, and mortality from severe malaria all remain very high. Uganda has made progress in implementing key malaria control measures, in particular distribution of insecticide-impregnated bednets, indoor residual spraying of insecticides, utilization of artemisinin-based combination therapy to treat uncomplicated malaria, and provision of intermittent preventive therapy for pregnant women. However, despite enthusiasm regarding the potential for the elimination of malaria in other areas, there is no convincing evidence that the burden of malaria has decreased in Uganda in recent years. Major challenges to malaria control in Uganda include very high malaria transmission intensity, inadequate health care resources, a weak health system, inadequate understanding of malaria epidemiology and the impact of control interventions, increasing resistance of parasites to drugs and of mosquitoes to insecticides, inappropriate case management, inadequate utilization of drugs to prevent malaria, and inadequate epidemic preparedness and response. Despite these challenges, prospects for the control of malaria have improved, and with attention to underlying challenges, progress toward the control of malaria in Uganda can be expected.

Assessing the performance of nurses in the management of malaria patients in Tanzania

BACKGROUND

In Tanzania, nurses play an important role in the management of patients with malaria. The study was conducted to identify the current status of the performance of nurses in the management of malaria patients, in order to provide the baseline data before the training intervention.

METHODS

The study was conducted at 19 government health facilities in four districts of Tanzania. In order to assess the performance of nurses, 60 procedures involved in the management of malaria patients were observed and evaluated. Additionally, exit interviews were conducted with 60 malaria patients or caretakers upon leaving the health facilities.

RESULTS

Of the 60 procedures observed, only 4 satisfied the standard established in the national guideline for treatment and diagnosis of malaria. The proportions of the interviewed patients who were able to correctly provide information were: 83.7-88% on home treatment topics; 6.1-33.3% on follow-up after treatment; and 48.3% on preventive measures on malaria.

CONCLUSION

The nurses do not satisfy the required standard in the management of malaria patients. The weak areas identified by the study are the quinine IV administration and health education provided to patients. Conducting a training programme for nurses and the provision of working aids, such as a dosage table and a wall chart, are recommended. Furthermore, in order to alleviate incorrect dosage in intravenous quinine administration associated with dosage calculation, the possibility of adopting treatment drugs that can be administered by other dosage routes could be explored.

The parasite clearance curve

Parasite clearance rates are important measures of anti-malarial drug efficacy. They are particularly important in the assessment of artemisinin resistance. The slope of the log-linear segment in the middle of the parasite clearance curve has the least inter-individual variance and is the focus of therapeutic assessment. The factors affecting parasite clearance are reviewed. Methods of presentation and the approaches to analysis are discussed.

Treatment of African children with severe malaria - towards evidence-informed clinical practice using GRADE

Background

Severe malaria is a major contributor of deaths in African children up to five years of age. One valuable tool to support health workers in the management of diseases is clinical practice guidelines (CPGs) developed using robust methods. A critical assessment of the World Health Organization (WHO) and Kenyan paediatric malaria treatment guidelines with quinine was undertaken, with a focus on the quality of the evidence and transparency of the shift from evidence to recommendations.

Methods

Systematic reviews of the literature were conducted using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool to appraise included studies. The findings were used to evaluate the WHO and Kenyan recommendations for the management of severe childhood malaria.

Results

The WHO 2010 malaria guidance on severe malaria in children, which informed the Kenyan guidelines, only evaluated the evidence on one topic on paediatric care using the GRADE tool. Using the GRADE tool, this work explicitly demonstrated that despite the established use of quinine in the management of paediatric cases of severe malaria for decades, low or very low quality evidence of important outcomes, but not critical outcomes such as mortality, have informed national and international guidance on the paediatric quinine dosing, route of administration and adverse effects.

Conclusions

Despite the foreseeable shift to artesunate as the primary drug for treatment of severe childhood malaria, the findings reported here reflect that the particulars of quinine therapeutics for the management of severe malaria in African children have historically been a neglected research priority. This work supports the application of the GRADE tool to make transparent recommendations and to inform advocacy efforts for a greater research focus in priority areas in paediatric care in Africa and other low-income settings.

Quinine, an old anti-malarial drug in a modern world: role in the treatment of malaria

Quinine remains an important anti-malarial drug almost 400 years after its effectiveness was first documented. However, its continued use is challenged by its poor tolerability, poor compliance with complex dosing regimens, and the availability of more efficacious anti-malarial drugs. This article reviews the historical role of quinine, considers its current usage and provides insight into its appropriate future use in the treatment of malaria. In light of recent research findings intravenous artesunate should be the first-line drug for severe malaria, with quinine as an alternative. The role of rectal quinine as pre-referral treatment for severe malaria has not been fully explored, but it remains a promising intervention. In pregnancy, quinine continues to play a critical role in the management of malaria, especially in the first trimester, and it will remain a mainstay of treatment until safer alternatives become available. For uncomplicated malaria, artemisinin-based combination therapy (ACT) offers a better option than quinine though the difficulty of maintaining a steady supply of ACT in resource-limited settings renders the rapid withdrawal of quinine for uncomplicated malaria cases risky. The best approach would be to identify solutions to ACT stock-outs, maintain quinine in case of ACT stock-outs, and evaluate strategies for improving quinine treatment outcomes by combining it with antibiotics. In HIV and TB infected populations, concerns about potential interactions between quinine and antiretroviral and anti-tuberculosis drugs exist, and these will need further research and pharmacovigilance.

Genetic variations in ABCB1 and CYP3A5 as well as sex influence quinine disposition among Ugandans

Quinine is one of the most effective antimalarial drugs, although its clinical use is limited as a result of its narrow safety margin. Quinine is a substrate of the polymorphic p-glycoprotein and CYP3A4/3A5. This study aimed to examine the effects of genetic variations in ABCB1 and CYP3A5 genes, sex, demographic, and biochemical variables (serum albumin, creatinine, alanine aminotransferase and albumin) on quinine disposition among Ugandans. Quinine (600 mg) was orally administered to 140 healthy volunteers. Quinine and its metabolite 3-hydroxyquinine concentrations were determined from 16-hour postdose plasma by high-performance liquid chromatography. CYP3A5 activity was measured using quinine/3-hydroxyquinine ratio (metabolic ratio). Genotyping for a total of 20 single nucleotide polymorphisms in ABCB1 (n = 13) and CYP3A5 (n = 7) was done using Taqman and minisequencing on microarray. There were 20.5- and 13-fold variations in body weight-adjusted plasma quinine concentrations (mean +/- standard deviation, 5.26 +/- 2.5 mumol/L; range, 0.88-18.10 mumol/L) and quinine-to-3-hydroxyquinine metabolic ratio (mean +/- standard deviation, 7.68 +/- 3.3 mumol/L; range, 1.66-22.3 mumol/L), respectively. Weight-adjusted plasma quinine concentration was significantly influenced by sex and ABCB1 haplotype. There was a significant sex difference in quinine metabolic ratio, women being faster metabolizers than men (P = 0.01). CYP3A5 genotype/haplotype significantly (P = 0.03) influenced quinine disposition with a clear CYP3A5*1 gene dose effect. The result confirms that quinine disposition is influenced mainly by sex as well as by ABCB1 and CYP3A5 genotypes. Despite being fast metabolizers, women display higher quinine bioavailability than men in Uganda. This may have clinical significance in determining an individual's susceptibility to quinine-associated adverse reactions such as cinchonism.

Intrarectal quinine versus intravenous or intramuscular quinine for treating Plasmodium falciparum malaria

BACKGROUND

In children with falciparum malaria, a proprietary quinine preparation (adjusted to make it less acidic) administered rectally may be easier to use and less painful than intramuscular or intravenous administration. However, rectal quinine may be less effective.

OBJECTIVES

To compare intrarectal quinine with intravenous or intramuscular quinine for treating malaria caused by Plasmodium falciparum.

SEARCH STRATEGY

In May 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE, EMBASE, LILACS, and CINAHL. We also searched conference proceedings, contacted individual researchers and a pharmaceutical company, and checked reference lists.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing intrarectal quinine with intramuscular and intravenous quinine for treating people with uncomplicated and severe Plasmodium falciparum malaria.

DATA COLLECTION AND ANALYSIS

We independently assessed each trial's risk of bias quality and extracted data, including adverse event data. We analysed dichotomous data using the odds ratio and continuous data using the mean difference.

MAIN RESULTS

Ten randomized controlled trials, all involving children only (total of 1417 children), fulfilled the inclusion criteria. The same investigator was involved in nine of the trials. Seven trials compared proprietary intrarectal with intravenous quinine, and seven trials compared it with intramuscular treatment. We detected no statistically significant difference between intrarectal and intravenous or intramuscular routes for death, parasite clearance by 48 hours and seven days, parasite clearance time, fever clearance time, coma recovery time, duration of hospitalization, and time to drinking. The trials reporting on these outcomes were small, which resulted in large confidence intervals for all outcomes apart from duration of hospitalization. One large trial (898 children) reported that intrarectal was less painful than intramuscular administration.

AUTHORS' CONCLUSIONS

We detected no difference in the effect on parasites and clinical illness for intrarectal quinine, but most trials were small. Pain may be less with intrarectal proprietary, buffered quinine preparations (made less acidic by adjustment of the pH to 4.5). Further larger trials in patients with severe malaria and in adults are required before the intrarectal route can be recommended.

Sublingual sugar for hypoglycaemia in children with severe malaria: a pilot clinical study

Background

Hypoglycaemia is a poor prognostic indicator in severe malaria. Intravenous infusions are rarely feasible in rural areas. The efficacy of sublingual sugar (SLS) was assessed in a pilot randomized controlled trial among hypoglycaemic children with severe malaria in Mali.

Methods

Of 151 patients with presumed severe malaria, 23 children with blood glucose concentrations < 60 mg/dl (< 3.3 mmol/l) were assigned randomly to receive either intravenous 10% glucose (IVG; n = 9) or sublingual sugar (SLS; n = 14). In SLS, a teaspoon of sugar, moistened with a few drops of water, was gently placed under the tongue every 20 minutes. The child was put in the recovery position. Blood glucose concentration (BGC) was measured every 5–10 minutes for the first hour. All children were treated for malaria with intramuscular artemether. The primary outcome measure was treatment response, defined as reaching a BGC of >= 3.3 mmol/l (60 mg/dl) within 40 minutes after admission. Secondary outcome measures were early treatment response at 20 minutes, relapse (early and late), maximal BGC gain (CGmax), and treatment delay.

Results

There was no significant difference between the groups in the primary outcome measure. Treatment response occurred in 71% and 67% for SLS and IVG, respectively. Among the responders, relapses occurred in 30% on SLS at 40 minutes and in 17% on IVG at 20 minutes. There was one fatality in each group. Treatment failures in the SLS group were related to children with clenched teeth or swallowing the sugar, whereas in the IVG group, they were due to unavoidable delays in beginning an infusion (median time 17.5 min (range 3–40).

Among SLS, the BGC increase was rapid among the nine patients who really kept the sugar sublingually. All but one increased their BGC by 10 minutes with a mean gain of 44 mg/dl (95%CI: 20.5–63.4).

Conclusion

Sublingual sugar appears to be a child-friendly, well-tolerated and effective promising method of raising blood glucose in severely ill children. More frequent repeated doses are needed to prevent relapse. Children should be monitored for early swallowing which leads to delayed absorption, and in this case another dose of sugar should be given. Sublingual sugar could be proposed as an immediate "first aid" measure while awaiting intravenous glucose. In many cases it may avert the need for intravenous glucose.

[Intramuscular injections of quinine and tetanus at the Centre Hospitalier Universitaire of Brazzaville, Congo]

Intramuscular injections are known for their iatrogenic complications. IM quinine is a routine procedure in Congo for drug resistant malaria management. In this short note, the authors evaluate tetanus relative to intramuscular injection of quinine among the cases of tetanus treated in the infectious diseases unit of "Centre Hospitalier Universitaire of Brazzaville". This study was conducted from January to December 2005 regarding 18 cases of tetanus among which 5 infected after intramuscular injection of quinine. Their level of severity was significantly higher with a high mortality rate (post intramuscular: 4 deaths out of 5; other cases: 3 deaths out of 13). Tetanus was generalized in 17 cases. A significant difference between the intramuscular and the non-intramuscular injection was observed regarding the pulse (p < 0.05), the level of severity (p < 0.005) and deaths (p < 0.005). Awareness-raising campaigns with populations and medical staff about the risks of intramuscular injections as well as vaccination schedule should be regularly implemented.