MD-354: What is It Good For?

MD-354 (meta-chlorophenylguanidine) has been identified as a member of a novel class of 5-HT₃ serotonin receptor agonists. MD-354 is a 5-HT₃ receptor partial agonist that has been shown to behave as an agonist in some assays, and as an antagonist in others. MD-354 also binds at α-adrenoceptors (ARs) and displays an affinity for α_2B-ARs comparable to its affinity for 5-HT₃ receptors. Although devoid of antinociceptive actions following systemic administration alone, MD-354 markedly enhances the antinociceptive actions of clonidine in the mouse tail-flick assay without potentiating the sedative side effects of clonidine. Although studies with MD-354 are still in progress, some pharmacological findings are described here. MD-354-related agents may represent drug adjuvants for the relief of severe pain.