Megalomicin is a Micromonospora-produced macrolide antibiotic complex. Megalomicin A component was studied most extensively. It inhibited the ATP-dependent acidification of lysosomes and intra-Golgi transport in vitro. Megalomicin induces a powerful inhibitory effect on HIV-1 replication at nontoxic concentrations by preventing the processing of HIV-1 gp160 envelope protein and the subsequent formation of infectious viral particles.

Avermectin B1a (AVM B1a), a widely used insecticide and acaricide, is reported to both activate and inhibit gamma-aminobutyric acidA (GABA(A)) receptor function in mammalian brain. Avermectin B1a is an antiparasitic agent that paralyzes nematodes without causing hypercontraction or flaccid paralysis. AVM B1a binds to two different sites in the GABA-gated chloride channel with dual effects, i.e., activating the channel on binding to the high-affinity site and blocking it on further binding to the low-affinity site.

Napitane [A 75200, ABT 200] is a norepinephrine uptake inhibitor and α2 adrenoceptor antagonist. It was undergoing clinical trials with Abbott in the USA as a treatment for depression. However it was discontinued later. Napitane is a potent alpha 2-adrenoceptor antagonist (Ki = 1.2 nM) with modest norepinephrine uptake-blocking activity (IC50 = 841 nM).

9-(N-methyl-L-isoleucine)-cyclosporin A (NIM-811, SDZ 811) is a cyclosporin A analog that is completely devoid of immunosuppressive capacity but exhibits potent and selective anti-human immunodeficiency virus type 1 (HIV-1) activity. NIM-811 interferes at two stages of the viral replication cycle: (i) translocation of the preintegration complex to the nucleus and (ii) production of infectious virus particles. NIM-811 induces a concentration-dependent reduction of HCV RNA in the replicon cells with an IC50 of 0.66 uM at 48 h. NIM-811 blocks the mitochondrial permeability transition induced by calcium and inorganic phosphate. NIM-811 blocks cell killing and prevents in situ mitochondrial inner membrane permeabilization and depolarization during tumor necrosis factor-α–induced apoptosis to cultured rat hepatocytes.Novartis discontinued development of SDZ 811 as an oral therapy for hepatitis C and HIV-1 infections.

Orvepitant is a novel generation brain penetrant, selective and potent, small molecule NK-1 receptor antagonist. Orvepitant’s (GW823296) mode of action and developability characteristics made it a suitable development candidate for the treatment of common anxiety disorders, posttraumatic stress disorder and major depressive disorder. It’s in phase II clinical trials as an effective inhibitor of itch-associated response.

Tolquinzole is an antidepressant agent.

Acridorex (BS 7573a) is an anorectic agent.

Ocfentanil, a compound structurally similar to the opioid analgesic fentanyl, was developed in the early 1990’s with the hope that it would provide a better clinical safety profile than fentanyl. The receptor pharmacology of ocfentanil appears to share pharmacodynamic effects with fentanyl and other μ opioid agonists, including analgesia, sedation, and respiratory depression. In rodents, ocfentanil was approximately 2.5 times more potent as an analgesic than fentanyl and had a shorter duration of action. Because the preclinical research suggested that ocfentanil had a better safety profile than fentanyl, it was selected for clinical evaluation. Like other μ opioid agonists, ocfentanil has been reported to produce itching, nausea, sedation, and severe respiratory depression. Chest pain, psychosis, and agitation have also been reported. In humans, however, ocfentanil had a similar potency (3 ug/kg ocfentanil produced effects that were comparable to 5 ug/kg fentanyl) and side-effects profile as fentanyl so further clinical development was discontinued. Ocfentanil is not approved in any country for medical useand is under national control in Canada, the United Kingdom, and China.