Bunazosin (E-643) is a quinazoline derivative with a1-adrenoceptor blocking activity. It has been clinically used both as a systemic antihypertensive as well as an ocular hypotensive drug. The major adverse effect associated with the use of bunazosin is orthostatic hypotension or its consequences (e.g. dizziness). Others adverse effects include headache, sweating, nausea, dry mouth, abdominal pain, diarrhea, and constipation. The effects of Bunazosin may be enhanced by diuretics and other antihypertensive agents and decreased by Rifampicin.

Etoperidone is an atypical antidepressant introduced in Europe in 1977. The activity of etoperidone is made mainly by its major metabolite 1-(3'-chlorophenyl)piperazine (mCPP). mCPP binds with different affinity to most of the serotonergic receptors and adrenergic receptors. This metabolite is an agonist of 5-HT2c and an antagonist of 5-HT2a. Part of etoperidone structure contributes to the activity in the α-adrenergic receptors. Etoperidone has been studied for the treatment of depression, tremors in Parkinson, extrapyramidal symptoms and male impotence. It is not certain if it was ever approved and marketed but its current status is withdrawn.

Oxypertine (Equipertine, Forit, Integrin, Lanturil, Lotawin, Opertil) is a neuroleptic drug and was originally introduced as a treatment for schizophrenia in the 1960s. Oxypertine is an indole derivative with general properties similar to those of the phenothiazine, chlorpromazine. It has been given by mouth in the treatment of various psychoses including schizophrenia, mania, and disturbed behaviour, and of severe anxiety. Like reserpine and tetrabenazine, oxypertine depletes catecholamines, though not serotonin, possibly underlying its neuroleptic efficacy. The molecular structure is strongly similar to solypertine and milipertine.

Chlorpromazine pamoate (also known as chlorpromazine embonate) is a salt of pamoic acid and a chlorpromazine. Pamoate salts are used in pharmaceutical formulations because they show slow dissolution and are useful in formulations where extended duration of action is required. Chlorpromazine is a phenothiazine antipsychotic. It also exerts sedative and antiemetic activity. The precise mechanism whereby the therapeutic effects of chlorpromazine are produced is not known. It has a wide range of activity arising from its depressant actions on the CNS and its alpha-adrenergic blocking and antimuscarinic activities. Chlorpromazine is a dopamine inhibitor; the turnover of dopamine in the brain is also increased. There is some evidence that the antagonism of central dopaminergic function, especially at the D2-dopaminergic receptor, is related to therapeutic effect in psychotic conditions.

Besipirdine is a potential novel first-in-class oral treatment for over active bladder currently in Phase II development, with a mechanism of action clearly different from that of antimuscarinics. It was under evaluation by Aventis up to phase III for Alzheimer’s disease, involving the administration of the compound to over 1500 patients. However, this research has been discontinued. Besipirdine antagonizes alpha-2 and alpha-1 adrenoceptors and inhibits both norepinephrine and serotonin uptake. The most common adverse events were asymptomatic postural hypotension and asymptomatic bradycardia.

Urapidil is an anti-hypertensive agent approved in Europe for the treatment of the corresponding disease. The drug acts by activating 5HT1a receptor and inhibiting alpha1-adrenergic receptors.

Niaprazine is a potent and selective antagonist of 5-HT2A and alpha-1 adrenergic receptors. It was used for the treatment of sleep disturbances in children and was investigated for the treatment of sleep disorders in patients with attention-deficit hyperactivity disorder and autistic disorder.

Bucindolol is a third-generation, non-selective β-adrenergic receptor blocker, that acts on both β-1 and β-2 receptors. Bucindolol’s additional α-1 antagonistic activity contributes to its mild vasodilator effect. It was rejected by the FDA for the heart failure, because of the unreviewed submissions deal with comparative effectiveness, clinical pharmacology, some aspects of pharmacogenetic data, and toxicology/metabolism. In addition, bucindolol is in the phase II of clinical trial for the treatment of atrial fibrillation.

Ifenprodil (marketed under the brands Vadilex; Dilvax; Creocral; Cerocral) is a selective NMDA receptor (glutamate) antagonist. Additionally, ifenprodil inhibits GIRK channels, and interacts with alpha1 adrenergic, serotonin, and sigma receptors. Ifenprodil acts as a vasodilator. Ifenprodil is a medicine available in a number of countries worldwide, but not in US.

Proroxan is a non-selective а-adrenoblocker. Proroxan was found to prevent the development of hypertensive crises and improve cerebral bioelectrical parameters in most of hypertensive patients. Proroxan has been used as an antihypertensive and in the treatment of Ménière’s disease, motion sickness, and allergic dermatitis.