Nerispirdine, an acetylcholine release enhancer and a K+/Na+ use-dependent channel blocker, was in clinical development with sanofi-aventis for the treatment of multiple sclerosis. Nerispirdine is not proconvulsant. It can inhibit axonal K(+) channels and this mechanism may underlie the ability of the drug to enhance neuronal conduction. Nerispirdine can also inhibit neuronal Na(+) channels, a mechanism that may explain why nerispirdine lacks proconvulsant activity.

FLEZELASTINE, a phthalazinone derivative, an anti-asthmatic/anti-allergic agent. It exhibits inhibition of histamine release and 5-lipoxygenase, calcium antagonistic properties and antagonism at the histamine H1 receptor. FLEZELASTINE is a racemate consisting of (+)- and (-)-enantiomers. Both enantiomers contribute to the pharmacodynamic efficacy of racemic flezelastine.

Darglitazone is a member of the thiazolidinedione class of drugs and an agonist of peroxisome proliferator-activated receptor-γ (PPAR-γ), an orphan member of the nuclear receptor superfamily of transcription factors. It has a variety of insulin-sensitizing effects, such as improving glycemic and lipidemic control, and is used in the treatment of metabolic disorders such as type II diabetes. Darglitazone sodium had been in phase I clinical trials by Pfizer for the treatment of type 2 diabetes. However, this study has been discontinued.

Enadoline (CI-977) is a potent and selective agonist at the kappa-opioid receptor. Enadoline is a potent antinociceptive agent. Clinical use of enadoline was associated with dose-limiting neuropsychiatric adverse events. Enadoline may yet find some application against ischaemic stroke and severe head injury, presumably in comatose patients.

Efegatran (GYKI 14766; LY 294468) is a tripeptide D-methyl-phenylalanyl-prolyl-arginal thrombin inhibitor. It was developed by IVAX for the potential treatment of thromboembolic disorders, mainly myocardial infarction. However, information about the further development is not available.

Thiorphan is the first potent synthetic inhibitor of enkephalinase. Thiorphan displays antinociceptive activity after systemic administration. Thiorphan also inhibits to a lesser extent the widely distributed angiotensin-converting enzyme, a carboxydipeptidase implicated in blood pressure regulation. Thiorphan failed to potentiate allergen-induced airway responses in asthma. Thiorphan significantly reduced the castor oil-induced diarrhea in rats when administered intravenously but not when administered intracerebroventricularly. Racecadotril, via its active metabolite thiorphan, was consistently effective in animal models and patients with various forms of acute diarrhea by inhibiting pathologic (but not basal) secretion from the gut without changing gastro-intestinal transit time or motility.

Bemarinone (ORF 16600) is a positive inotropic and vasodilator agent with potential clinical utility in the management of congestive heart failure. The compound selectively and competitively inhibited cyclic AMP phosphodiesterase fraction III. However, further studies were discontinued

Iododoxorubicin is an anthracycline derivative patented by Farmitalia Carlo Erba S.p.A. for cancer treatment. In preclinical studies, Iododoxorubicin has demonstrated significantly reduced levels of cardiotoxicity compared to anthracyclines. Unfortunately, during phase II clinical trials Iododoxorubicin failed to demonstrate efficacy in an advanced breast cancer patient

Nanterinone [UK 61260], a phosphodiesterase III inhibitor, was undergoing II evaluation with Pfizer in the US for the treatment of heart failure. Nanterinone is a positive inotropic and balanced-type vasodilating drug, only partially based on phosphodiesterase III inhibition. Preliminary data from controlled studies suggest satisfactory long-term efficacy and safety.

Batelapine (or CGS 13429), an antipsychotic drug, that was undergoing preclinical development, but the further studied were discontinued