Sigma receptor ligands

Patent Pending The sigma receptors σ1 and σ2 bind to ligands such as 4-PPBP,[1] SA 4503, ditolylguanidine, dimethyltryptamine[2] and siramesine. σ–receptors were once thought to be a type of opioid receptor, because the d- stereoisomers of the benzomorphan class of opioid drugs reduced coughing, as do some other opioid derivatives such as dextromethorphan[clarification needed]. However, such drugs had no effects at μ (Mu), κ (kappa), or δ (Delta) receptors.