sentences:  Among amodiaquine users, several rare but serious side effects have been reported and linked to variants in the CYP2C8 alleles.CYP2C8*1 is characterized as the wild-type allele, which shows an acceptable safety profile, while CYP2C8*2, *3 and *4 all show a range of "poor metabolizer" phenotypes.People who are poor metabolizers of amodiaquine display lower treatment efficacy against malaria, as well as increased toxicity.