Tonabersat is a unique compound with demonstrated activity as a gap-junction inhibitor in animal studies. In preclinical and clinical trials, tonabersat was well tolerated, with no cardiovascular effects; the pharmacokinetic profile suggested its usefulness in the prophylaxis of migraine. The basis of its high efficacy is inhibiting neuronal hyperexcitability and trigeminal nerve stimulated neurogenic inflammation in rodent models. Tonabersat inhibits the CSD (cortical spreading depression) that is believed to underlie the aura of migraine.

Cyclobutoic acid is a synthetic analog of mevalonic acid, developed by the Italian company Farmitalia Carlo Erba SPA. The compound inhibited the incorporation of [14C] into CO2, fatty acids and cholesterol, and was used for the treatment of hepatic deficiency.

Bicifadine (DOV-220075) is not a narcotic and is well-tolerated and, in preclinical studies, has been shown not to act at any opiate receptor, but inhibits monoamine neurotransmitter uptake by recombinant human transporters in vitro with a relative potency of norepinephrine:serotonin:dopamine of 1:2:17. Bicifadine was in Phase II clinical trial for pain caused by diabetic neuropathy, in addition, was in phase III clinical trial to treat Chronic Low Back Pain, but that studies were discontinued

Iomethin I-131 is radioiodinated quinoline derivative with potential tumor localizing activity. In animal models, Iomethin I-131 administrations lead to regression of the malignant melanoma and its metastases.

Propisergide is a lysergic acid derivative patented by Sandoz Ltd. as an α-adrenoceptor-blocking agent with marked specific 5-HT receptor antagonist activity. In preclinical trials, Propisergide inhibited tryptamine tremor in rats and adrenaline-induced aggregation of blood platelets.

Relcovaptan is a potent, orally active nonpeptide vasopressin V1a antagonist that was undergoing clinical development with Sanofi-Synthélabo (formerly Sanofi) in France. SR49059 is specifically and selectively antagonizes the effect of vasopressin on the V1a receptor in animals’ and in humans. The drug has been shown to have an excellent safety profile in single and repeated dose toxicological studies in animals. In the human uterus in vitro, SR49059 caused a dose-dependent inhibition of vasopressin V1a receptor-mediated activity of myometrial strips and isolated uterine arteries. In vivo in nonpregnant women, an inhibition of vasopressin-induced uterine activity has been observed.

Imanixil (also known as HOE-402) was developed as a potent cholesterol-lowering compound, which inhibits VLDL production, and consequently attenuates atherosclerosis development. This drug participated in phase I clinical trial for the treatment of hyperlipidemia, however, this study was discontinued.

Sulfaloxic acid is a benzamide derivative patented by Chemische Fabrik von Heyden A.-G. as an antibacterial agent.

Cutamesine, an agonsit of brain sigma 1 receptors, was developed by Santen Pharmaceutical for the treatment of cognitive diseases. The drug was tested in phase II in patients with major depressive disorders and for recovery of patients with stroke, however its development was terminated for the given conditions. Currently M's science corporation is developing cutamesine for Amyotrophic lateral sclerosis and Retinitis pigmentosa as more suitable target diseases.

Revenast is an anti-allergic compound that is rapidly and extensively metabolized in animals. It is not acting as an anti-histaminic. Revenast has low bioavailability (reported in monkeys) and high protein binding (in humans). Information about current use of this compound is not available.