A simple dose regimen of artesunate and amodiaquine based on age or body weight range for uncomplicated falciparum malaria in children: comparison of therapeutic efficacy with standard dose regimen of artesunate and amodiaquine and artemether-lumefantrine

Temporal changes in haematocrit following artemisinin-based combination treatments of uncomplicated falciparum malaria in children

Background

Artemisinin-based combination treatments (ACTs) or intravenous artesunate are used in over 100 countries for uncomplicated or severe falciparum malaria. Although intravenous artesunate may cause delayed haemolytic anaemia, there is little evaluation of the temporal changes in haematocrit following ACTs.

Methods

Clinical and parasitological parameters were measured before and following treatment of uncomplicated falciparum malaria in children with artesunate-amodiaquine (AA) or artemether-lumefantrine (AL) over 6-weeks. Changes in haematocrit were characterized in individual patients based on a haematocrit <30 % or ≥30 % before and following treatment. Kinetics of the deficit in haematocrit from <30 % until attainment of ≥30 % were estimated by a non-compartment model.

Results

In 248 of 1180 children eligible for evaluation, common temporal patterns were: no change or increase in haematocrit from ≥ 30 % [50 % of patients], haematocrit >30 % at presentation declining to <30 % within 2 weeks (early monophasic fall) [19 % of patients], and haematocrit <30 % at presentation increasing to ≥ 30 % [23 % of patients]. Haematocrit >30 % at presentation declining to <30 %, 3–5 weeks later (late monophasic fall) occurred in 7 children (3 %). Fall in haematocrit ≥5 units following treatment occurred in 57 children [23 %] between 14 and 28 days after treatment began. Baseline parasitaemia and proportion with > 100,000μL^-1 asexual forms were significantly higher in children with ≥5 units compared to <5 units fall in haematocrit 21 or 28 days after treatment began. Irrespective of pattern, declines in haematocrit deficit from <30 % were mono-exponential, with similar half-times for AA- and AL-treated children (1.32 d versus 1.14 d). Anaemia half-time correlated significantly positively with anaemia recovery time in the same patients (r = 0.55, P < 0.0001). Bland-Altman analysis of 9 or 10 multiples of anaemia half-time and anaemia recovery times showed narrow limit of agreement with insignificant biases (P = 0.19 or 0.63, respectively).

Conclusions

In uncomplicated falciparum malaria, increases or falls in haematocrit are common following ACTs. Falls in haematocrit ≥ 5 units are common and may or may not result in early or late anaemia. In children who recovered from acute falciparum malaria-associated anaemia following ACTs, decline in haematocrit deficit is mono-exponential.

Trials registration

Pan African Clinical Trial Registry PACTR201508001188143, 3 July 2015; PACTR201508001191898, 7 July 2015 http://www.pactr.org.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1219-y) contains supplementary material, which is available to authorized users.

The emerging threat of artemisinin resistance in malaria: focus on artemether-lumefantrine

The development of artemisinin resistance in the Greater Mekong Subregion poses a significant threat to malaria elimination. Artemisinin-based combination therapies including artemether-lumefantrine (AL) are recommended by WHO as first-line treatment for uncomplicated Plasmodium falciparum malaria. This article provides a comprehensive review of the existing and latest data as a basis for interpretation of observed variability in parasite sensitivity to AL over the last 5 years. Clinical efficacy and preclinical data from a range of endemic countries are summarized, including potential molecular markers of resistance. Overall, AL remains effective in the treatment of uncomplicated P. falciparum malaria in most regions. Establishing validated molecular markers for resistance and strict efficacy monitoring will reinforce timely updates of treatment policies.

Efficacy and safety of fixed-dose artesunate-amodiaquine vs. artemether-lumefantrine for repeated treatment of uncomplicated malaria in Ugandan children

The safety and efficacy of the two most widely used fixed-dose artemisinin-based combination therapies (ACT), artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) are well established for single episodes of uncomplicated Plasmodium falciparum malaria, but the effects of repeated, long-term use are not well documented. We conducted a 2-year randomized, open-label, longitudinal, phase IV clinical trial comparing the efficacy and safety of fixed-dose ASAQ and AL for repeated treatment of uncomplicated malaria in children under 5 years at Nagongera Health Centre, Uganda. Participants were randomized to ASAQ or AL and all subsequent malaria episodes were treated with the same regimen. 413 children were enrolled and experienced a total of 6027 malaria episodes (mean 15; range, 1–26). For the first malaria episode, the PCR-corrected-cure rate for ASAQ (97.5%) was non-inferior to that for AL (97.0%; 95% CI [−0.028; 0.037]). PCR-corrected cure rates for subsequent malaria episodes that had over 100 cases (episodes 2–18), ranged from 88.1% to 98.9% per episode, with no clear difference between the treatment arms. Parasites were completely cleared by day 3 for all malaria episodes and gametocyte carriage was less than 1% by day 21. Fever clearance was faster in the ASAQ group for the first episode. Treatment compliance for subsequent episodes (only first dose administration observed) was close to 100%. Adverse events though common were similar between treatment arms and mostly related to the disease. Serious adverse events were uncommon, comparable between treatment arms and resolved spontaneously. Anemia and neutropenia occurred in <0.5% of cases per episode, abnormal liver function tests occurred in 0.3% to 1.4% of cases. Both regimens were safe and effective for repeated treatment of malaria.

Trial Registration

Current Controlled Trials NCT00699920

Therapeutic efficacies of artemisinin-based combination therapies in Nigerian children with uncomplicated falciparum malaria during five years of adoption as first-line treatments

The therapeutic efficacies of 3-day regimens of artesunate-amodiaquine and artemether-lumefantrine during 5 years of adoption as first-line treatments were evaluated in 811 ≤ 12-year-old malarious children. Compared with artemether-lumefantrine, amodiaquine-artesunate significantly reduced the proportion of children with fever and parasitemia 1 day after treatment (day 1; P < 0.008 for both). The proportion of parasitemic children on day 2 and gametocytemia on presentation and carriage reduced significantly over the years (P < 0.000001 and P < 0.03, respectively; test for trend). Overall efficacy was 96.5% (95% confidence interval [CI] = 94.5-98.6) and remained unchanged over the years (P = 0.87; test for trend). Kinetics of parasitemias after treatments were estimated by a non-compartmental model. Declines of parasitemias were monoexponential, with a mean elimination half-life of 1.09 hours (95% CI = 1.0-1.16). Parasitemia half-lives and efficacy were similar for both regimens and in all ages. Artesunate-amodiaquine and artemether-lumefantrine remain efficacious treatments of uncomplicated falciparum malaria in Nigerian children 5 years after adoption.