<unk>  is a dihydrofolate reductase inhibitor, and is a metabolite of the antimalarial drug proguanil; its formation in vivo has been thought to be primarily responsible for the antimalarial activity of proguanil.  However, more recent work has indicated that, while proguanil is synergistic with the drug atovaquone (as in the combination Malarone),<unk>  is in fact antagonistic to the effects of atovaquone, suggesting that, unlike<unk> , proguanil may have an alternative mechanism of antimalarial action besides dihydrofolate reductase inhibition.
Although<unk>  is not currently in general use as an antimalarial, the continuing development of resistance to current antimalarial drugs has led to renewed interest in studying the use of<unk>  in combination with other drugs.
Cycloguanil
Sulfathiazole
Trichlormethiazide
Amsacrine
Bencyclane
Ferruginol
Phthalylsulfathiazole
Quinine