Iloperidone, also known as Fanapt, Fanapta, and previously known as Zomaril, is an atypical antipsychotic for the treatment of schizophrenia. Iloperidone shows high affinity and maximal receptor occupancy for dopamine D2 receptors in the caudate nucleus and putamen of the brains of schizophrenic patients. The improvement in cognition is attributed to iloperidone's high affinity for α adrenergic receptors. Iloperidone also binds with high affinity to serotonin 5-HT2a and dopamine 3 receptors. Iloperidone binds with moderate affinity to dopamine D4, serotonin 5-HT6 and 5-HT7, and norepinephrine NEα1 receptors. Furthermore, iloperidone binds with weak affinity to serotonin 5-HT1A, dopamine D1, and histamine H1 receptors. Iloperidone is indicated for the treatment of acute schizophrenia.

Etiguanfacine, also known as SSP-1871, is an α2-adrenoreceptor agonist.

Clonidine is a centrally acting α2 adrenergic agonist and imidazoline receptor agonist used to treat high blood pressure, attention deficit hyperactivity disorder, anxiety disorders, tic disorders, withdrawal (from either alcohol, opioids, or smoking), migraine, menopausal flushing, diarrhea, and certain pain conditions. Clonidine treats high blood pressure by stimulating α2 receptors in the brain, which decreases peripheral vascular resistance, lowering blood pressure. It has specificity towards the presynaptic α2 receptors in the vasomotor center in the brainstem. This binding decreases presynaptic calcium levels, thus inhibiting the release of norepinephrine (NE). It has also been proposed that the antihypertensive effect of clonidine is due to agonism on the I1 receptor (imidazoline receptor), which mediates the sympatho-inhibitory actions of imidazolines to lower blood pressure. Clonidines mechanism of action in the treatment of ADHD is to increase noradrenergic tone in the prefrontal cortex (PFC) directly by binding to postsynaptic α2A adrenergic receptors and indirectly by increasing norepinephrine input from the locus coeruleus. Clonidine indicated in the treatment of hypertension. Clonidine hydrochloride tablets may be employed alone or concomitantly with other antihypertensive agents. The US Food and Drug Administration (FDA) has approved clonidine for the treatment of attention deficit hyperactivity disorder (ADHD), under the trade name of Kapvay alone or with stimulants in 2010, for pediatric patients aged 6–17 years.

Droxidopa (Northera, Chelsea Therapeutics) is a synthetic catecholamino acid precursor of norepinephrine indicated for the treatment of orthostatic dizziness or lightheadedness in adult patients with symptomatic neurogenic orthostatic hypotension (NOH) caused by primary autonomic failure, dopamine beta-hydroxylase deficiency, and non-diabetic autonomic neuropathy. Droxidopa was approved as oral therapy in February 2014 under the FDA’s accelerated approval program. Droxidopa is directly metabolized to norepinephrine by dopadecarboxylase. The specific mechanism of action of the drug is not known completely, but it is supposed to exert the pharmacological effects through norepinephrine and not through the parent molecule or other metabolites. It increases blood flow to the brain by stimulating peripheral arterial and venous vasoconstriction.

Oxymetazoline is an adrenergic alpha-agonist, direct acting sympathomimetic, used as a vasoconstrictor to relieve nasal congestion The sympathomimetic action of oxymetazoline constricts the smaller arterioles of the nasal passages, producing a prolonged (up to 12 hours), gentle and decongesting effect. Oxymetazoline elicits relief of conjunctival hyperemia by causing vasoconstriction of superficial conjunctival blood vessels. The drug's action has been demonstrated in acute allergic conjunctivitis and in chemical (chloride) conjunctivitis. Oxymetazoline is self-medication for temporary relief of nasal congestion associated with the common cold, hay fever, or other upper respiratory allergies. Oxymetazoline is available over-the-counter as a topical decongestant in the form of oxymetazoline hydrochloride in nasal sprays such as Afrin, Operil, Dristan, Dimetapp, oxyspray, Facimin, Nasivin, Nostrilla, Sudafed OM, Vicks Sinex, Zicam, SinuFrin, and Mucinex Full Force. Due to its vasoconstricting properties, oxymetazoline is also used to treat nose bleeds and eye redness.

Aldioxa is the generic name for the metal complex, dihydroxyaluminum allantoinate, which is hydrolyzed to allantoin and aluminium hydrate at the gastric mucosa. Aldioxa was approved in Japan to improve subjective symptoms or objective of gastric/duodenal ulcer and gastritis. It was discovered, that aldioxa ameliorates delayed gastric emptying through its antagonistic activity on the α-2 adrenergic receptor. The most commonly reported adverse reactions include constipation.

Conessine is a plant steroid alkaloid that acts as a potent and specific antagonist of histamine H3 receptors. Conessine displayed high affinity at both rat and human H3 receptors (pKi = 7.61 and 8.27) and generally high selectivity against other sites, including histamine receptors H1, H2, and H4. Conessine was found to efficiently penetrate the CNS and reach very high brain concentrations. Although the very slow CNS clearance and strong binding to adrenergic receptors discouraged focus on conessine itself for further development, its potency and novel steroid-based skeleton motivated further chemical investigation. Modification based on introducing diversity at the 3-nitrogen position generated a new series of H3 antagonists with higher in vitro potency, improved target selectivity, and more favorable drug-like properties. Conessine also has high affinity for the adrenergic receptors. Conessine has being shown to possess anti-malarial activity. In India conessine finds therapeutic use for treatment of dysentery and helminthic disorders.

Efaroxan (RX 821037) is a potent and selective alpha(2)-adrenoceptor antagonist. Additionally, Efaroxan is a selective antagonist at the imidazoline I1 receptor. Efaroxan promotes insulin secretion, in the absence of exogenous agonists, by a mechanism that involves inhibition of ATP-regulated K+ channels. Efaroxan was in clinical trials for the treatment of diabetes mellitus however its development has been discontinued.

ICI-118,551 is a selective subtype β2 adrenergic receptor (adrenoreceptor) antagonist. ICI-118,551 binds to the β2 subtype with at least 100 times greater affinity than to other subtypes of the beta adrenoceptor β1 or β3. Pharmacological experiments proved that the right shift of the norepinephrine dose-response curve by ICI-118,551 was mediated via a beta(2)-adrenoceptor/G(i/o) protein-dependent pathway enhancing NO production in the endothelium. These results were corroborated in beta-adrenoceptor and endothelial NO synthase knockout mice where ICI had no effect. ICI-118,551 increased vascular lumen diameter in lung sections and reduced pulmonary arterial pressure under normoxia and under hypoxia in the isolated perfused lung model. These effects were found to be physiologically relevant, because ICI-118,551 specifically decreased pulmonary but not systemic blood pressure in vivo. Thus, it has been suggested that ICI-118,551 is a pulmonary arterial-specific vasorelaxant and might be a potential novel therapeutic agent for the treatment of pulmonary arterial hypertension. It was also demonstrated that systemic topical administration of ICI 118,551 results in decreased intraocular pressure in both eyes of rabbits, indicating that at least part of the ocular hypotensive effect of topical ICI 118,551 is mediated through systemic absorption. However, ICI 118,551 did not lower blood pressure in hypertensive patients known to respond to therapy with atenolol or propranolol.

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.