Fresh , clinical P. falciparum isolates were also tested in the presence of several drugs , including chloroquine , mefloquine , quinine , halofantrine , atovaquone and qinghaosu derivatives .
The microculture tetrazolium assay (MTA): another colorimetric method of testing Plasmodium falciparum chemosensitivity. Malarial lactate dehydrogenase (LDH), which uses 3-acetyl pyridine adenine dinucleotide as coenzyme in a reaction leading to the formation of pyruvate from L-lactate, may be used to study the susceptibility of Plasmodium falciparum to a drug in vitro. Several methods to determine the activity of this enzyme are available. One, the colorimetric method of Makler and colleagues, was modified slightly, by using sodium-2,3-bis-[2-methoxy-4-nitro-5-sulphophenyl]-2H-tetrazolium-5 - carboxanilide (XTT) and following the reaction by measuring the optical density at 450 nm. Using two, culture-adapted strains of P. falciparum, this LDH assay was compared with the unmodified Makler's assay and with the isotopic microtest based on the incorporation of tritium-labelled hypoxanthine. Fresh , clinical P. falciparum isolates were also tested in the presence of several drugs , including chloroquine , mefloquine , quinine , halofantrine , atovaquone and qinghaosu derivatives . The results of the three assays were correlated for all the drugs tested except atovaquone. The two enzymatic assays are non-radioactive, rapid, reliable, inexpensive to perform and semi-automatic. However, they do require an initial parasitaemia of 2% with a haematocrit of 1.8%.
### Instruction:
            Given the context about compound efficacy for the given treatment mentioned within the input, mentioned the compounds 
            that can co-occur for the mentioned treatment

            ### Input:
            The microculture tetrazolium assay (MTA): another colorimetric method of testing Plasmodium falciparum chemosensitivity. Malarial lactate dehydrogenase (LDH), which uses 3-acetyl pyridine adenine dinucleotide as coenzyme in a reaction leading to the formation of pyruvate from L-lactate, may be used to study the susceptibility of Plasmodium falciparum to a drug in vitro. Several methods to determine the activity of this enzyme are available. One, the colorimetric method of Makler and colleagues, was modified slightly, by using sodium-2,3-bis-[2-methoxy-4-nitro-5-sulphophenyl]-2H-tetrazolium-5 - carboxanilide (XTT) and following the reaction by measuring the optical density at 450 nm. Using two, culture-adapted strains of P. falciparum, this LDH assay was compared with the unmodified Makler's assay and with the isotopic microtest based on the incorporation of tritium-labelled hypoxanthine. Fresh , clinical P. falciparum isolates were also tested in the presence of several drugs , including chloroquine , mefloquine , quinine , halofantrine , atovaquone and qinghaosu derivatives . The results of the three assays were correlated for all the drugs tested except atovaquone. The two enzymatic assays are non-radioactive, rapid, reliable, inexpensive to perform and semi-automatic. However, they do require an initial parasitaemia of 2% with a haematocrit of 1.8%.

            ### Response:
            chloroquine, mefloquine, quinine, halofantrine, atovaquone
            