| Relation Name/Additional Label | Expanded Form | Count |
| CHD/has_parent | has child relationship in a Metathesaurus source vocabulary /Has parent | 20777 |
| PAR/parent_of | has parent relationship in a Metathesaurus source vocabulary /Parent of | 20777 |
| SY/ | source asserted synonymy./Empty relationship attribute | 16256 |
| RO/may_be_treated_by | has relationship other than synonymous, narrower, or broader/May be treated by | 14779 |
| RO/may_treat | has relationship other than synonymous, narrower, or broader/May treat | 14779 |
| RO/physiologic_effect_of | has relationship other than synonymous, narrower, or broader/Physiologic effect of | 11387 |
| RO/has_physiologic_effect | has relationship other than synonymous, narrower, or broader/Has physiologic effect | 11387 |
| RO/contraindicated_with_disease | has relationship other than synonymous, narrower, or broader/Contraindicated with disease | 11322 |
| RO/has_contraindicated_drug | has relationship other than synonymous, narrower, or broader/Has contraindicated drug | 11322 |
| RO/mechanism_of_action_of | has relationship other than synonymous, narrower, or broader/Mechanism of action of | 7304 |
| RO/has_mechanism_of_action | has relationship other than synonymous, narrower, or broader/Has mechanism of action | 7304 |
| RO/therapeutic_class_of | has relationship other than synonymous, narrower, or broader/Therapeutic class of | 5127 |
| RO/has_therapeutic_class | has relationship other than synonymous, narrower, or broader/Has therapeutic class | 5127 |
| CHD/ | has child relationship in a Metathesaurus source vocabulary /Empty relationship attribute | 4004 |
| PAR/ | has parent relationship in a Metathesaurus source vocabulary /Empty relationship attribute | 4004 |
| RO/structural_class_of | has relationship other than synonymous, narrower, or broader/Has structural class | 3433 |
| RO/has_structural_class | has relationship other than synonymous, narrower, or broader/Structural class of | 3433 |
| RO/may_prevent | has relationship other than synonymous, narrower, or broader/May prevent | 2620 |
| RO/may_be_prevented_by | has relationship other than synonymous, narrower, or broader/May be prevented by | 2620 |
| RO/contraindicated_class_of | has relationship other than synonymous, narrower, or broader/Contraindicated class of | 1916 |
| RO/has_contraindicated_class | has relationship other than synonymous, narrower, or broader/Has contraindicated class | 1916 |
| RO/has_contraindicated_mechanism_of_action | has relationship other than synonymous, narrower, or broader/Has contraindicated mechanism of action | 454 |
| RO/contraindicated_mechanism_of_action_of | has relationship other than synonymous, narrower, or broader/Contraindicated mechanism of action of | 454 |
| RO/contraindicated_physiologic_effect_of | has relationship other than synonymous, narrower, or broader/Contraindicated physiologic effect of | 274 |
| RO/has_contraindicated_physiologic_effect | has relationship other than synonymous, narrower, or broader/Has contraindicated physiologic effect | 274 |
| RO/induces | has relationship other than synonymous, narrower, or broader/Induces | 169 |
| RO/induced_by | has relationship other than synonymous, narrower, or broader/Induced by | 169 |
| RO/may_diagnose | has relationship other than synonymous, narrower, or broader/May diagnose | 157 |
| RO/may_be_diagnosed_by | has relationship other than synonymous, narrower, or broader/May be diagnosed by | 157 |
| RO/pharmacokinetics_of | has relationship other than synonymous, narrower, or broader/Pharmacokinetics of | 79 |
| RO/has_pharmacokinetics | has relationship other than synonymous, narrower, or broader/Has pharmacokinetics | 79 |
| RO/site_of_metabolism | has relationship other than synonymous, narrower, or broader/Site of metabolism | 43 |
| RO/metabolic_site_of | has relationship other than synonymous, narrower, or broader/Metabolic site of | 43 |
| RO/active_metabolites_of | has relationship other than synonymous, narrower, or broader/Active metabolites of | 8 |
| RO/has_active_metabolites | has relationship other than synonymous, narrower, or broader/Has active metabolites | 8 |
| RO/may_inhibit_effect_of | has relationship other than synonymous, narrower, or broader/May inhibit effect of | 2 |
| RO/effect_may_be_inhibited_by | has relationship other than synonymous, narrower, or broader/Effect may be inhibited by | 2 |
