If you cannot find the information that you are looking for, then you can request assistance from the PharmGKB team.
In citing the PharmGKB please refer to:
T.E. Klein, J.T. Chang, M.K. Cho, K.L. Easton, R. Fergerson, M. Hewett, Z. Lin, Y. Liu, S. Liu, D.E. Oliver, D.L. Rubin, F. Shafa, J.M. Stuart and R.B. Altman, "Integrating Genotype and Phenotype Information: An Overview of the PharmGKB Project" (220k PDF), The Pharmacogenomics Journal (2001) 1, 167-170.