Combinatorial retrieval example. Using scopolamine as the query drug, the top-10 retrieval results are shown for single-drug and combinatorial retrieval, with ATC codes shared with the query indicated by colors. For combinatorial retrieval, the drugs are ranked (CombRank) based on their first appearance in the retrieved pairs (either CombDrug1 or CombDrug2). In the example, using both single-drug and combinatorial retrieval, a match for ATC code N05 is found at the first rank. However, combinatorial retrieval also provides a match for the other ATC code S01 already at the first rank, whereas single-drug retrieval finds a match only at rank 9. The result demonstrates that the combinatorial retrieval approach can be beneficial for polypharmacologic queries.