ICI-118551 is a selective β2 adrenergic receptor antagonist, that was originally developed for the regulation of blood pressure. ICI-118551 crosses the blood-brain barrier and it was in phase I clinical trials for the treatment of chronic anxiety. Currently, ICI-118,551 has no known therapeutic use in humans although it has been used widely in research to understand the action of the β2 adrenergic receptor, as few other specific antagonists for this receptor are known.

Fipamezole is a fluorine substituted imidazole compound with high antagonist specificity for the presynaptic alpha2-adrenoceptor. There were no significant differences between the affinity of Fipamezole for the different subtypes, thus characterizing Fipamezole as a non-subtype–selective alpha2 antagonist. Fipamezole had been in phase III clinical trials for the treatment of dyskinesia associated with Parkinson’s disease. Detected side effects are hypertension, nausea, vomiting, dysgeusia, facial flushing.

Dexefaroxan is a selective alpha 2-adrenergic receptor antagonist. Вexefaroxan improved TgCRND8 (protein-transgenic mouse model of Alzheimer's disease) behavioral phenotypes and increased BDNF mRNA expression without affecting amyloid-β peptide levels. Dexefaroxan treatment also enhanced the number and complexity of the dendritic arborizations of polysialated neural cell adhesion molecule-positive neurons. The trophic effects of dexefaroxan on newborn cells might involve an increase in brain-derived neurotrophic factor, which was upregulated in afferent noradrenergic fiber projection areas and in neurons in the granule cell layer. By promoting the survival of new endogenously formed neurons, dexefaroxan treatment represents a potential therapeutic strategy for maintaining adult neurogenesis in neurodegenerative conditions, such as Alzheimer's disease, that affect the hippocampus. Dexefaroxan increases neuron survival in the olfactory bulb of the adult rat in vivo, putatively as a result of reducing the apoptotic fate of telencephalic stem cell progenies.

Akuammigine is an oxindole alkaloid. Akuammigine shows antiadrenergic activity and thus reduces heart rate.

(+)-octopamine is an enantiomer of octopamine, a naturally occurring phenolamine acting as a neurotransmitter in invertebrates. Octopamine is considered to be trace amine present in mammalian tissues at very low (nanomolar) concentrations. Generally, the (+)-enantiomers of octopamine are less active than the (-)-enantiomers at adrenergic receptors. However (+)-octopamine is more potent than the (-)-octopamine as an inhibitor of semicarbazide-sensitive amine oxidase.

(-)-octopamine is an enantiomer of octopamine, a naturally occurring phenolamine acting as a neurotransmitter in invertebrates. Octopamine is considered to be trace amine present in mammalian tissues at very low (nanomolar) concentrations. Generally, the (-)-enantiomers of octopamine are more active than the (+)-enantiomers at adrenergic receptors. However (+)-octopamine is more potent than the (-)-octopamine as an inhibitor of semicarbazide-sensitive amine oxidase.

BRL-44408, a potent (Ki=8.5 nM) and selective (>50-fold) α2A-adrenoceptor antagonist (KB=7.9 nM). BRL-44408 revealed antidepressant- and analgesic-like activity through selective alpha2A-adrenoceptor antagonism. Preclinical characterization of the neurochemical and behavioural profile of BRL-44408 suggests that selective antagonism of alpha2A-adrenoceptors may represent an effective treatment strategy for mood disorders and visceral pain. BRL-44408 increases hippocampal noradrenalin release following systemic administration. BRL-44408 has potential therapeutic application in the treatment of extrapyramidal side effects produced by some antipsychotic medications.