Doxepin is a tricyclic antidepressant formulated as a mixture of E-(trans) and Z-(cis) stereoisomers. It inhibits CYP2D6 activity in vivo.

Milnacipran inhibits both norepinephrine transporter (NET) and norepinephrine transporter (SERT) with IC50 of 77 nM and 420 nM, respectively.

Darifenacin is a selective M3 muscarinic receptor antagonist with pKi of 8.9.

Tripelennamine is a widely used H1 antagonist, inhibiting PhIP glucuronidation with IC50 of 30 μM.

Betahistine is a histamine H3 receptor inhibitor with IC50 of 1.9 μM.

Amitriptyline inhibits serotonin receptor, norepinephrine receptor, 5-HT4, 5-HT2 and sigma 1 receptor with IC50 of 3.45 nM, 13.3 nM, 7.31 nM, 235 nM and 287 nM, respectively.

Azatadine is an histamine and cholinergic inhibitor with IC50 of 6.5 nM and 10 nM, respectively.

Ropinirole a selective dopamine D2 receptors agonist with Ki of 29 nM.