<unk>  (R41468) is a drug with affinity for multiple G protein-coupled receptors (GPCR). It is a highly selective antagonist for serotonin<unk> A receptors, but also has moderate selectivity for<unk> C receptors and for alpha-1 adrenergic receptors, and very high affinity for histamine H1
receptors. Therefore,<unk>  can not be used to reliably discriminate between the effects of<unk> A and<unk> C  receptors when both are present in an experimental system.  Furthermore, when alpha-1 and H1 receptors are present,  the effects of<unk>  can potentially represent a complex interaction of serotonin, adrenergic, and histamine receptor systems. Complicating the matter further is the fact that<unk>  has moderate affinity for delta-1t adrenergic receptor (~200 nM) and 5-HT6 (~300 nM) receptors  as well as weak affinity for dopamine D1  and D2   receptors (~300 nM and ~500 nM respectively).<unk>  at levels of 500 nM or greater are thus potentially affecting at least 8 different GPCRs from 4 different families. (All affinity levels taken from the NIMH Psychoactive Drug Screening Program database )
Receptors for which<unk>  has high affinity binding:<unk> A = 2-3 nM (rat and human)<unk> C = 50 nM (rat), 100 nM (human)
alpha-1 adrenergic = ~40 nM
Histamine H1 = 2 nM
Solubility:
6 mg/mL 0.1 M HCl
10 mM H20
3.3 mg/mL ethanol
52 mg/mL DMSO<unk>  was discovered at Janssen Pharmaceutica in 1980.
Ketanserin
Nabilone
Sumatriptan 
Naratriptan
Zolmitriptan 
Eletriptan
Rizatriptan
Frovatriptan