A comparative study of Artesunate-Lumefantrine vs. Chloroquine-Pyrimethamine-Sulfadoxine efficacy for the treatment of uncomplicated Plasmodium falciparum in tribal population in Bastar (Chhattisgarh).
H Singh, N Dulhani, B Kumar, P Tiwari
adverse effects., artesunate, chloroquine, lumefantrine, malaria, pyrimethamine, sulfadoxine
H Singh, N Dulhani, B Kumar, P Tiwari. A comparative study of Artesunate-Lumefantrine vs. Chloroquine-Pyrimethamine-Sulfadoxine efficacy for the treatment of uncomplicated Plasmodium falciparum in tribal population in Bastar (Chhattisgarh).. The Internet Journal of Pharmacology. 2009 Volume 8 Number 1.
Malaria remains a major health problem world wide because of development of resistance to currently available therapies. The impact of drug resistant falciparum malaria is considerable.  Chloroquine-resistant Plasmodium falciparum has now spread to most malarial areas, and has become a significant problem in Southeast Asia. 
Increased childhood morbidity and mortality in Africa due to Chloroquine resistance is now well documented. Malaria related anemia itself is an important cause of morbidity and mortality, affecting an estimated 1.5 to 6 million African children and is associated with a case fatality rate (CFR) of 15%. [4, 5]
From a drug policy perspective, drug resistance is the most critical factor in reducing the useful life span of a drug and undermining drug policy.  Because of growing concerns about the development of resistance to antimalarial drugs when used alone, combination therapy is increasingly being regarded as the best strategy to prolong the useful therapeutic life span of these drugs. [7, 8, 9]
Artemisinin and its derivatives produce more rapid resolution of fever and parasitaemia than any other antimalarial agent due to their rapid reduction in parasite biomass.  Fixed-dose combination of Artemether, a derivative of artemisinin, and lumefantrine, a molecule developed by the Academy of Military Medical Sciences in Beijing, People’s Re-public of China. Artemether has been shown to be beneficial in the treatment of malaria, but recrudescence is common when it is used as a single drug.  The safety and efficacy of this Combination has been evaluated in several studies of uncomplicated falciparum malaria, and has been shown to be safe and efficacious.[12, 13]
The key to success is to use combination drugs to which parasites are still sensitive. In vivo resistance to the artemisinin has not been described but it can be induced in the laboratory. 
Adding artesunate (an artemisinin derivative) had a profound positive effect when added to a standard antimalarial drug without adding to toxicity. This proved a key principle. As a result, further interest in developing artemisinin based combinations was given a boost, deployment studies were organized, and WHO has endorsed fully the use of artemisinin based combinations for treating falciparum malaria. 
The WHO also recommends artemisinin based combination therapies (ACT) for treatment of uncomplicated malaria, due to decreased sensitivity of Plasmodium falciparum to Chloroquine and Sulphadoxine/Pyrimethamine (SP) [16, 17, 18]
Currently the only fixed-dose, artemisinin based combination is Artemether/lumefantrine. The six dose regimen is highly efficacious against multidrug resistant P. falciparum, it is also well tolerated. 
In India, the selection of therapy of the treatment of acute, uncomplicated P.falciparum malaria is becoming more difficult due to the increasing resistance of the parasite to Chloroquine.  In spite of the increasing numbers of resistant strains, Chloroquine was recommended by the National Vector Borne Disease Control Programme (NVBDCP) previously known as National Malaria Eradication Programme of the Government of India as standard therapy for patients with uncomplicated P.falciparum malaria in India, but according to NATIONAL DRUG POLICY ON MALARIA (2008), Chloroquine is recommended for treatment of all P.vivax and P.falciparum only in areas with low risk of plasmodium falciparum (Pf) and considered sensitive to Chloroquine. Artemisinin combination therapy (Artesunate + Sulpha Pyrimethamine) combination is recommended for the treatment of Pf cases in qualified areas like Chloroquine-resistant areas, cluster of Blocks surrounding resistant areas and identified high endemic districts. For this reason, Chloroquine was selected as the comparative drug in this study. 
Material and method
The study was conducted in department of medicine with the help of department of pharmacology in Government Medical College Jagdalpur, Chhattisgarh, during the peak malaria transmission season of 2009. The study was reviewed and approved by the Institutional Review Board (Human Ethic’s Committee)
Malaria transmission in south Chhattisgarh is unstable with a peak between March and August. All age groups are susceptible and the majority of infections are symptomatic. In this P.falciparum accounts for10-20% of infections.
Inclusion: All male and female patients with acute, uncomplicated P.falciparum malaria presenting to Government Medical College and hospital Jagdalpur, were enrolled into the study if they were at least 16years old and microscopic examination confirmed P.falciparum or mixed infection (including P.falciparum parasitaemia 1,000parasites/l) and they were willing to comply with the study protocol and gave written informed consent.
Exclusion: Reasons for exclusion were pregnancy/lactation, P.falciparum asexual parasitaemia <1,000/l or >200,000/l, an inability to tolerate oral medication, severe or complicated malaria requiring parentral treatment, antimalarial treatment taken within 2 weeks preceding the start of the study, other investigational drugs taken within 30 days prior to start of the trial, known hypersensitivity or allergy to Chloroquine or any artemisinin derivatives, and severe renal, hepatic, cardiac, or nutritional impairment.
During this period ninety one patients satisfied the enrolment criteria according to the WHO protocol for the assessment and monitoring of antimalarial drug efficacy for the treatment of uncomplicated falciparum malaria.  They were randomly assigned with one of the following treatments: group I (AL) 4 tablets, each tablet containing 20 mg Artemether and 120 mg lumefantrine given orally at 0, 8, 24, 32, 48, and 60 hr (total 24 tablets) and the patients randomized to receive CPS ( 2nd group) received 4+2+2+2 tablets (each tablet containing 150 mg of Chloroquine base) given at 0,6–8, 24, and 48 hr plus combination of Pyrimethamine-Sulfadoxine containing 1500mg (25mg/kg) of sulfadoxine and 75mg (1.25mg/kg) of Pyrimethamine at presentation (day 0). If necessary, patients were provided with antipyretics (Paracetamol tablets, 10–15 mg/kg 8 h for 24–48 h).
All drugs were given orally, and were administered in direct supervision of member of study group on in inpatient basis for this they were hospitalized for 8 days. Day1was taken as the day of admission .During this period, each patient under went a clinical examination and laboratory investigation (including an estimation of glucose-6-phosphate dehydrogenase at baseline) for assessment of safety and efficacy. During the first 72 hr, patients were monitored for parasites in blood and oral temperature was recorded at 6-hourly interval. Thereafter, body temperature was measured every 12 hr and blood microscopy performed once a day until day 8. Patients were then seen regularly in the outpatient clinic. This consisted of enquiry about the patient's well being, presence or absence of initial presenting symptoms, presence of additional symptoms, measurement of body temperature, heart and respiratory rates, and a blood smear for the quantification of parasitaemia.
Thick and thin blood films prepared from a finger prick were Giemsa-stained and were examined by light microscopy under an oil-immersion objective, at × 1000 magnification.
Routine hematological (hematocrit) and biochemical tests (concentrations of alanine aminotransferase, aspartate aminotransferase, bilirubin and creatinine) were performed in every patient enrolled (using an auto-analyzer), prior to treatment and on day 14 to detect any drug-associated effects. The 28-day cure rate was the primary end point of therapeutic efficacy in this study. It is defined as the proportion of patients with clearance of sexual parasitaemia within seven days of initiation of treatment, without subsequent recrudescence.
Side effects were defined as symptoms and signs that first occurred or became worse after treatment was started. Any new events occurring during treatment were also considered as side effects.
Table 1 Demographic and clinical characteristic of patients
Table 2: Therapeutic response
Table 3 : Frequency of adverse effects reported
Figure: Frequency of adverse effects reported in two combination
The study was conducted from March to August 2009. Among the 91 patients, 55 were treated with AL and 36 with CPS combination respectively. The baseline information included gender, age, weight, organomegaly, temperature, initial parasite count and mean duration of illness in both group’s as shown in Table 1. Eleven patients were lost to follow-up on day 15, 16, 16, 21, and 23 from the AL combination treated group and on day 13, 16, 16, 23, 23 and 27 from the CPS treated group (Table 2). Only three treatment failure was recorded in the CPS combination treated grou
The fever clearance time and parasite clearance time were longer in CPS treated group (1.1 days vs. 1 day, P = 0.03; and 1.7 days vs. 2.1 days, P < 0.003, respectively), the fever clearance time is just significant in favor of AL treated group, but parasitaemia clearance time in AL group is much shorter than the CPS treated group which is statistically very significant. (Table 2) the overall cured rate was 90% and 100% in CPS and AL combination groups respectively, that was statistically significant in favor of AL treated group.
Both treatments were well tolerated but few common adverse effects started or worsened after baseline recording are shown in table-3. Abdominal pain (8.2%) was the most common adverse effects noted in AL combination group and Nausea/vomiting (14.7%) was the most common adverse effect noted in CPS treated group, which could not be differentiated between the clinical signs and symptoms of malarial infection or drug-related. However, the severities of these side effects were only mild to moderate. No serious adverse event was found and no patient were withdrawn because of drug intolerance.
Hematological, biochemical and other parameters remained normal before and after treatment in all subjects (normal biochemical parameters for the area: ALT 0–40 i.u/l; AST: 0–37 i.u/l; serum creatinine: 0.5–1.5 mg/dl; serum bilirubin: 0.5–1.0 mg/dl). Thrombocytopenia, defined as platelet count <150 × 103 mm3, was present in 8 and 3 patients in AL and CPS groups respectively, at enrolment, but was not seen on day 14 in any patient (normal value for the area: 150–390 × 103 mm3).
The three patients with Chloroquine plus Pyrimethamine-Sulfadoxine treatment failures responded to AL. Fever cleared in all three patients within 24 h of commencing treatment with Artesunate plus Lumefantrine and parasitaemia cleared within 48 h. The cure rate on day 28 of re-treatment was 100%.
Many countries have adopted ACTs as the first line drugs for the treatment of uncomplicated falciparum malaria. The present study confirms that Artemether-lumefantrine is effective against falciparum malaria and well tolerated as combination.
These results have implication for countries that have adopted Artemisinin combination as the first line drug, and where both malaria species (Vivax and Falciparum) are prevalent and parasitological differentiation is not carried out in routine practices.
The ideal anti malarial or combination antimalarial should rapidly clear sexual parasitaemia and its associated clinical symptoms and signs within the shortest possible time, should not worsen or provoke anemia, and should hasten recovery from malaria-associated anemia. We have documented the effects of Artemether +lumefantrine in uncomplicated falciparum malaria in cohort of 55 patients, both parasitaemia clearance and fever clearance time were shorter in case of Artemether +lumefantrine treated patients as compared to Chloroquine+ Pyrimethamine-Sulfadoxine treated cohort of 36 patients. In above result the parasitaemia clearance time difference was statistically very significant and the fever clearance time was only just significant. Other important end point of this study was the percentage of patients cured at 28th days of follow up, and that was 100% in Artemether +Lumefantrine treated group and 90% in Chloroquine+ Pyrimethamine-Sulfadoxine treated group. A total of eleven patients were lost in different stages of study due to change in addresses or due to partial improvement or due to long distance from health center etc.
The drug combinations used were well tolerated. The reported common adverse reactions were abdominal pain, Nausea/vomiting, Pruritus and Headache, among them few have clear-cut causation but others were indistinguishable from the symptoms of malaria
Pyrimethamine-Sulfadoxine, and rarely, Chloroquine can induce haemolysis in Glucose 6 Phosphate dehydrogenase (G6PD) deficient subjects, but none of our patients, on follow up reported features suggestive of drug-induced hemolytic anemia. 
Artemisinin derivatives are highly effective antimalarial compounds against different stages of Plasmodium development.  This current consensus of antimalarial therapy has led to the adoption of ACT in India according to WHO guideline where Chloroquine (CQ) has reached high levels of treatment failure due to high level of resisistance. 
The partial failure of AL (8.9%) has shown in few studies, which were explained by less absorption of lumefantrine due to low fat diet, a situation that may be common in rural areas.  In addition, recrudescence of AL-treated individuals has been reported in studies from other parts of the world, [25, 26] but we didn’t encounter such problems, it may be due to better pharmacokinetic profile of patients or less number patients in present study.
Combinations, Artesunate-Lumefantrine and Chloroquine-Pyrimethamine-Sulfadoxine were well tolerated for the treatment of uncomplicated falciparum malaria in tribal population in Bastar (Chhattisgarh). However, Artesunate-Lumefantrine showed significantly higher efficacy than Chloroquine-Pyrimethamine-Sulfadoxine combination, this may be due to the high prevalence of resistance against Chloroquine combination and better patient’s compliance in artesunate-lumefantrine treatment.
We are grateful to Dr. SL Adile, Director, Medical Health Education, Govt. of Chhattisgarh, and Nodal Officer, Autonomous Society, Government Medical College, Jagdalpur (CG) without whose inspiration and support this work may not have been possible.