P-88-8991, (-)- is a metabolite of Iloperidone. It has functional affinity for noradrenergic, dopaminergic and serotoninergic receptors. Humans produce only one enantiomer stereospecifically following administration of Iloperidone. Preclinical studies revealed that P-88-8991, (-)- might be useful for the treatment of psychotic disorders such as schizophrenia and bipolar disorders.

P-88-8991, (+)- is a metabolite of Iloperidone. It has functional affinity for noradrenergic, dopaminergic and serotoninergic receptors. Humans produce only one enantiomer stereospecifically following administration of Iloperidone. Preclinical studies revealed that P-88-8991, (+)- might be useful for the treatment of psychotic disorders such as schizophrenia and bipolar disorders.

Dapiprazole is an alpha-1 adrenergic receptors antagonist which was developed for for the treatment of drug induced mydriasis produced by adrenergic or parasympatholytic agents. The drug was marketed under the name Rev-Eyes, however it was withdrawn from market due to its slow effect.

Guanadrel is a postganglionic adrenergic blocking agent. Uptake of guanadrel and storage in sympathetic neurons occurs via the norepinephrine pump or transporter. Guanadrel slowly displaces norepinephrine from its storage in nerve endings and thereby blocks the release of norepinephrine normally produced by nerve stimulation. The reduction in neurotransmitter release in response to sympathetic nerve stimulation, as a result of catecholamine depletion, leads to reduced arteriolar vasoconstriction, especially the reflex increase in sympathetic tone that occurs with a change in position. Guanadrel is used to treat and control hypertension.

Chlorprothixene (Taractan, Tarasan, Truxal) is a thioxanthine derivative developed by Lundbeck for the treatment of psychotic disorders. The drug exerts its activity by binding to and inhibiting serotonin receptors, dopamine receptors, muscarinic acetylcholine receptor, histamine H1 receptor and alpha1-adrenergic receptor.

Nylidrin (Buphenine, Arlidin) is a beta-adrenergic agonist. Nylidrin causes peripheral vasodilation, a positive inotropic effect, and increased gastric volume of gastric juice. It is used in the treatment of peripheral vascular disorders and premature labor. In peripheral vascular disorders, Arlidin (nylidrin HCl) increases walking ability and promotes healing of trophic ulcers. Nylidrin hydrochloride acts predominantly by beta-receptor stimulation. Beta stimulation with nylidrin has been demonstrated in a variety of isolated tissues from rabbits, guinea pigs and dogs. It has been shown to dilate arterioles in skeletal muscle and to increase cardiac output in the anesthetized dog and cat and in unanesthetized man. An increase in cerebral blood flow and a decrease in vascular resistance has also been reported. The result of this combination of actions is a greater blood supply to ischemic tissues, with usually minimal change in blood pressure. Arlidin may be of benefit in elderly patients with mild to moderate symptoms that are commonly associated with organic mental disorders. Short-term (3 months’ duration) and long-term (12 months’ duration) clinical studies have demonstrated a modest improvement in ability to perform general activities of daily living, self-care and in a capability for social interactions. The mechanism whereby nylidrin may provide relief of selected symptoms in some elderly patients with organic brain disorders is not known.

Tolazoline, also known as priscoline, was used in treatment of persistent pulmonary hypertension of the newborn. But that prescription was discontinued. Priscoline given intravenously produces vasodilatation, primarily due to a direct effect on vascular smooth muscle, and cardiac stimulation; the blood pressure response depends on the relative contributions of the two effects. Priscoline usually reduces pulmonary arterial pressure and vascular resistance. The mechanisms of its therapeutic effects are not clear, but is known, that tolazoline is a non-selective competitive α-adrenergic receptor antagonist and it possesses histamine agonist activity.

Phenylpropanolamine belongs to the sympathomimetic amine class of drugs and is structurally related to ephedrine. The effects of phenylpropanolamine are largely the result of alpha-adrenergic agonist activity resulting from both direct stimulation of adrenergic receptors and release of neuronal norepinephrine. Phenylpropanolamine is mainly used as a nasal decongestant. Phenylpropanolamine is also used as anorexiant in obesity and to treat urinary incontinence in veteranary. Phenylpropanolamine containing products has been withdrawn by FDA due to the association of phenylpropanolamine use with increased risk of hemorrhagic stroke.

Amosulalol is a beta- and alpha-1 adrenoceptor-blocking agent developed for the treatment of hypertension. Amosulalol does not cross blood brain barrier and does not have adverse affect on CNS system.The drug is marketed under the name Lowgan in Japan and Korea.

Abanoquil (UK-52,046), an antiarrhythmic drug, is an alpha 1-adrenoceptor antagonist, has been studied for the treatment of erectile dysfunction.