Pranidipine is the calcium channel blocker. Pranidipine did not affect the sensitivity of the contractile proteins to calcium. Pranidipine also did not alter cyclic GMP-induced relaxation in alpha-toxin-skinned vascular preparations. Pranidipine also prolonged glyceryl trinitrate-induced relaxation in the endothelium denuded rat aorta. Pranidipine enhances cyclic GMP-independent NO-induced relaxation of smooth muscle by a mechanism other than through NO-induced hyperpolarization. These effects were in direct contrast to amlodipine, another new 1,4-dihydropyridine calcium antagonist. Pranidipine increased blood velocity and probably blood flow in the optic nerve head, choroid, and retina of rabbits. Pranidipine was not detrimental to global cardiac function in animals with dilated cardiomyopathy. Pranidipine enhances relaxation produced by endothelium-derived relaxing factor in carotid artery. Pranidipine was investigated as pharmacological agent for the treatment of angina pectoris and hypertension.

Cronidipine (LF 2.0254) is a calcium channel blocker. LF 2.0254 inhibited in a time-dependent fashion K(+)- and Ca2(+)-induced contractions of rabbit aorta with respective IC50 of 2.7 nM and 1.7 nM. Cronidipine had a long-lasting antihypertensive action in spontaneously hypertensive rats and was able to decrease blood pressure and increase heart rate and plasma renin activity in hypertensive dogs.

Fluzinamide (AHR-8559), an anticonvulsant agent that was studied in patients with refractory partial seizures. However, information about the further development of this drug is not available.

LAVOLTIDINE, also known as loxtidine, is a highly potent and selective histamine H2-receptor antagonist. It is a member of triazoles. It produces gastric carcinoid tumors in rodents that is why its clinical development was discontinued.

There is no much available information related to the biological and pharmacological application of imidoline, but this compound has been found to be as potent as chlorpromazine in increasing striatal DOPA accumulation and prolactin secretion in vivo. Imidoline exhibited only weak inhibitory activity towards dopamine-sensitive adenylate cyclase and 3H-spiroperidol binding to striatal membranes in vitro. A proposed active conformation involves intramolecular hydrogen bonding between the protonated dimethylamino group and the oxygen of the imidazolidinone ring. The spatial relationship between the amine nitrogen and phenyl ring in this conformation allows proper fit of imidoline with key dimensions described for the dopamine receptor.

Mazapertine (RWJ-37796) is an arylpiperazine antipsychotic with high affinity to dopamine D2 and D3, serotonin 5-HT1A and alpha 1A-adrenergic receptors. It was being studied in the treatment of schizophrenia.

Etorphine was the first potent opiate agonist employed primarily for use in non-domestic and wild species. Etorphine was 500 times as potent as morphine, with a very rapid onset and short duration of action. In morphine-dependent subjects, etorphine suppressed abstinence but for a shorter period than morphine. Etorphine is a full opiate agonist and binds to multiple opiate sites in the central nervous system. It is believed to produce its clinical effects through binding the µ-, δ-, and κ- opiate sites. It has a potent effect on depressing the respiratory centers of the CNS thus resulting in apnea being commonly seen in immobilized animals. Etorphine revolutionized the ability of biologists and veterinarians to safely capture and restrain many species that previously could not be handled. Etorphine is not currently commercially available due to lack of production by the manufacturer.

Volinanserin (MDL-100,907) is a highly selective 5-HT2A receptor antagonist. It is widely used in scientific research to investigate the function of the 5-HT2A receptor. Volinanserin is also being trialed as a potential antipsychotic, antidepressant and treatment for insomnia. Volinanserin (M-100907) was in phase III trials for chronic schizophrenia. In August 1999, development was discontinued for acute schizophrenia (schizoaffective disorder) on the basis of poor results. M-100907 is also active in animal models involving blockade of NMDA glutamatergic channel receptors, an effect known to resemble some behavioral symptoms of schizophrenia in man. M-100907 is also claimed in other patents for the treatment of thromboembolic disorders, for the treatment of various developmental neurological disorders such as autism and attention deficit hyperactivity disorder.

Cloperidone is a quinazolinedione derivative with sedative and antihypertensive properties. Cloperidone was discovered in 1965 by Miles Laboratories. The activity of the compound was demonstrated by behavioral observations in dogs and cats, by rotarod and activity cage experiments in mice and in other models.