We present an approach to the extraction of relations between pharmacogenomics entities like drugs, genes and diseases which is based on syntax and on discourse. Particularly, discourse has not been studied widely for improving Text Mining. We learn syntactic features semi-automatically from lean document-level annotation. We show how a simple Maximum Entropy based machine learning approach helps to estimate the relevance of candidate relations based on dependency-based features found in the syntactic path connecting the involved entities. Maximum Entropy based relevance estimation of candidate pairs conditioned on syntactic features improves relation ranking by 68% relative increase measured by AUCiP/R and by 60% for TAP-k (k=10). We also show that automatically recognizing document-level discourse characteristics to expand and filter acronyms improves term recognition and interaction detection by 12% relative, measured by AUCiP/R and by TAP-k (k=10). Our pilot study uses PharmGKB and CTD as resources.