Mifentidine, a histamine H2 receptor antagonist, was studied to treat the duodenal ulcer. This drug was in phase II clinical trials when apparently further researches had been discontinued.

Picartamide had potent antisecretory and antiulcerogenic effects which were, at least, 10 times more pronounced than those of cimetidine. The mechanism of action of picartamide has not yet been determined but it seems that an anticholinergic or an H2 receptor antagonist effect should be excluded. The results show that picartamide is also active on the pure vagus-stimulated gastric acid secretion. The lack of effect upon gastric pepsin and plasma PP suggests that picartamide is not likely to act on the basolateral cholinergic receptor and that it affects further cellular steps involved in hydrogen ion secretion.

Rivanicline (also known as RJR-2403 or TC-2403) is a partial neuronal nicotinic acetylcholine receptor agonist. This compound binds primarily to the α4β2 receptor subtype. Rivanicline was originally developed for Alzheimer’s disease and shows pronounced anti-amnesic and increased recognition memory in rats. Because rivanicline also inhibits Interleukin-8 production, it has been further developed as a potential anti-inflammatory treatment for ulcerative colitis (in which nicotine is of therapeutic value but has adverse events). Rivanicline effectively inhibited TNF- and LPS-induced IL-8 production in different cell types, without toxic effects. Rivanicline was also evaluated as a potential compound for the development of nicotinic therapeutics to treat neurological diseases in cases of compromised cholinergic neurotransmission.

Peraclopone is a hypolidemic drug. It is an inhibitor of 7-Dehydrocholesterol reductase. Peraclopone potently inhibits the final step in cholesterol biosynthesis. Feeding this agent to rats leads to a rapid replacement of membrane cholesterol with its immediate precursor 7-dehydrocholesterol, and a dramatic reduction in plasma sterol concentration. Peraclopone caused a dose-dependent decrease in cholesterol and a concomitant accumulation of provitamin D3 (7-dehydrocholesterol) in the skin, which is accompanied by an increase in the plasma level of 25-hydroxyvitamin D3. Treatment with peraclopone dramatically alters membrane sterol content in many membranes including the microvillus membrane of both the jejunum and ileum. In the jejunal microvillus membrane a major change in chemical composition occurred, presumably in response to the alteration in membrane sterol. The net result was a significant decline in both the static and dynamic component of membrane fluidity.

Oxitriptyline, a tricyclic antidepressant that has never been marketed

Oximonam (also known as SQ 82,291) was developed as a monobactam antibiotic that had shown good activity against different bacteria of the family Enterobacteriaceae and Haemophilus influenzae and was no activity at all against staphylococci and against Pseudomonas aeruginosa.

Metioprim is a competitive inhibitor of bacterial dihydrofolate reductase with an in vitro activity against most important gram-negative and gram-positive bacteria causing urinary and respiratory tract infections. The use of this drug was studied in the treatment of pyelonephritis and against atypical mycobacterial infections - especially leprosy. Information about the current use of this compound is not available.

Metibride was developed as an antilipidemic agent. Information about the current use of this compound is not available.

PF-2545920 is an orally-active phosphodiesterase 10A (PDE10A) inhibitor originated by Pfizer, for the treatment of Huntington's disease. PF-2545920 was originally developed by Pfizer for the treatment of schizophrenia. But later clinical studies for Schizophrenia were discontinued. PF-2545920 is a potent and selective PDE10A inhibitor with IC50 of 0.37 nM, with >1000-fold selectivity over the PDE. PF-2545920 is active in a range of antipsychotic models, antagonizing apomorphine-induced climbing in mice, inhibiting conditioned avoidance responding in both rats and mice, and blocking N-methyl-D-aspartate antagonist-induced deficits in prepulse inhibition of acoustic startle response in rats, while improving baseline sensory gating in mice.