CGP-36742 (3-Aminopropyl-n-butyl-phosphinic acid) is one of the first GABAB receptor antagonists that can penetrate the blood-brain barrier after peripheral administration. Although its affinity for GABA B binding sites labeled with a tritiated agonist is modest, being in the low micromolar range, it displays significant pharmacological activity when administered either orally or parenterally. CGP 36742 was effective in the learned helplessness paradigm in rats, dose-dependently improving the escape failures induced by the inescapable shocks, suggesting that it may have an antidepressant profile. CGP36742 displays pronounced cognition enhancing effects in Rhesus monkeys in active and passive avoidance paradigms, in an eight-arm radial maze and a Morris water maze and in a social learning task. CGP36742 blocks the late inhibitory postsynaptic potential and the paired-pulse inhibition of population spikes recorded from CA1 pyramidal neurons of the hippocampus of rats in vitro and in vivo. CGP36742 significantly enhances the release of glutamate, aspartate, glycine and somatostatin in vivo. Chronic administration of CGP36742 causes an up-regulation of GABA(B) receptors in the frontal cortex of rats. The effects of CGP36742 on cognition were investigated in a double-blind, placebo-controlled study undertaken as the first assessment of the efficacy of CGP36742 in 110 patients age 59–85 years with Mild cognitive impairment. The results showed significant improvement in working memory, psychomotor speed and attention with SGS742 as compared with placebo. SGS742 appeared to be safe and well tolerated in this study.

Compound 552-02 is a potent, selective inhibitor of epithelial sodium channels that is effective in enhancing mucociliary clearance and is well tolerated when administered as a single dose by inhalation aerosol in normal healthy adult volunteers. Parion Sciences was developing 552 02 for the treatment of xerostomia, cystic fibrosis, chronic bronchitis, chronic obstructive pulmonary disease, radiation injuries. Compound 552-02 was specifically designed for aerosol delivery to the pulmonary system as a more selective, potent, long-acting ENaC blocker to promote an expansion in ASL volume, with or without hypertonic saline. Compound 552-02 was selected from a series of novel ENaC blockers to produce a selective block on airway epithelial sodium channels, with a potency up to 2 orders of magnitude greater than amiloride. 552-02 blocked the majority (95%) of Isc, with a calculated IC50 value of 7 nM. Drug development was discontinued.

Nelezaprine is a skeletal muscle relaxant.

Fosfocreatinine, a cardioprotectant that was used for the treatment of cardiac disorders. Information about the current use of this drug is not available.

Quatacaine is a methylpropionanilide derivative patented by Tanabe Seiyaku Co., Ltd. As local anaesthetic.

FLOTRENIZINE, a diarylmethylpiperazine derivative, is an antihistaminic agent.

Sitamaquine (WR-6026) is an orally active 8-aminoquinoline analog in development by the Walter Reed Army Institute, in collaboration with GlaxoSmithKline (formerly SmithKline Beecham), for the potential treatment of visceral leishmaniasis. Phase III trials for the treatment of visceral leishmaniasis had been initiated by March 2002, at which time GlaxoSmithKline hoped to file an MAA in 2003. By 1999, the compound had also undergone phase I trials in HIV-infected individuals for the treatment of Pneumocystis carinii infection. Preclinical studies have been conducted in primates and rodents for the potential treatment of Babesia microti infection.

Stacofylline is a xanthine derivative patented by ADIR for the treatment of migraine and asthenia.