Carbiphene (etomide, SQ 10,269) is a nonnarcotic analgesic agent for the relief of pain. SQ 10,269 is considered to be a non-addicting analgesic agent indicated for the relief of all types of pain, including post-operative pain and pain associated with chronic and recurrent diseases.

A potent, selective and orally active receptor antagonist of leukotriene D4, verlukast (MK-571), was discovered and developed from a styrylquinoline lead structure based on a hypothetical model of the leukotriene D4 receptor. MK-571 blocks the action of LTD4 in animals and man, and is effective in a number of animal models of antigen-induced bronchoconstriction at plasma concentration at or below 2 ug/mL. MK-571 also blocks antigen-induced asthmatic responses in man. MK-571 is a potent and selective leukotriene D4 (LTD4) antagonist and ABCC multidrug resistance protein 1(MRP1) inhibitor. The cysteinyl leukotrienes (CysLTs), LTC4, LTD4, and LTE4, mediate their actions through two distinct G-protein coupled receptors. LTD4 is the preferred ligand for the CysLT1 receptor, whereas LTC4 and LTD4 bind with approximately equal affinity to the CysLT2 receptor. MK-571 is a selective, orally active CysLT1 receptor antagonist. It blocks the binding of LTD4, but not LTC4, to human and guinea pig lung membranes with Ki values of 0.22 nM and 2.1 nM, respectively. MK-571 effectively blocks LTD4 activation of recombinant human and mouse CysLT1 receptors but is ineffective at blocking LTC4 or LTD4 activation of the recombinant human or murine CysLT2 receptors.

Loxoprofen (INN) is a non-steroidal anti-inflammatory drug in the propionic acid derivatives group. It is marketed in Brazil, Mexico and Japan by Sankyo as its sodium salt, loxoprofen sodium, under the trade name Loxonin, Argentina as Oxeno and in India as Loxomac. It is available in these countries for oral administration, and a transdermal preparation was approved for sale in Japan on January 2006. It is usually used to treat rheumatoid arthritis and osteoarthritis. It is also used to reduce pain and inflammation after surgery, wounds and tooth removal, as well as to bring down fever or ease pain induced by acute inflammation of upper respiratory tract Loxoprofen is a prodrug. When administered orally, loxoprofen sodium hydrate is absorbed from the gastrointestinal tract as an unchanged compound with only a modest gastric-mucosal irritation. It is then rapidly biotransformed into the active metabolite trans-OH form (SRS coordination) with a potent inhibitory effect on prostaglandin biosynthesis to exert its pharmacologic effects. Inhibition of prostaglandin biosynthesis constitutes the mechanism of action of this drug, the site of action being cyclooxygenase.

Bucindolol is a third-generation, non-selective β-adrenergic receptor blocker, that acts on both β-1 and β-2 receptors. Bucindolol’s additional α-1 antagonistic activity contributes to its mild vasodilator effect. It was rejected by the FDA for the heart failure, because of the unreviewed submissions deal with comparative effectiveness, clinical pharmacology, some aspects of pharmacogenetic data, and toxicology/metabolism. In addition, bucindolol is in the phase II of clinical trial for the treatment of atrial fibrillation.

Hydroquinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent (Ia) in the heart. Hydroquinidine is a d-rotatory alkaloid derived from cinchiona bark. It is closely related to quinidine, differing from the latter alkaloid only in containing two more atoms of hydrogen in the molecule. The drug causes increased action potential duration, as well as a prolonged QT interval. It is not approved by FDA, but marketed in Spain, France, Italy and Pakistan under the brand names Lentoquine, Sérécor LP, Idrochinidina Lirca and Austacute, respectively. Like all other class I antiarrhythmic agents, Hydroquinidine primarily works by blocking the fast inward sodium current (INa). Hydroquinidine is also used for the treatment of Malaria.

Thiocolchicoside is a muscle relaxant that has been authorised by national procedures in several EU Member States for use by mouth or injection into the muscles in the treatment of painful muscular disorders. Thiocolchicoside is marketed under the brand name Muscoril among others. Thiocolchicoside (TCC) is used clinically for its muscle relaxant, anti-inflammatory, and analgesic properties, and it has been shown to interact with gamma-aminobutyric acid (GABA) type A receptors (GABAARs) and strychnine-sensitive glycine receptors in the rat central nervous system.

Bopindolol (4-[benzoyloxy-3-tertbutylaminopropoxy]-2-methylindole hydrogen malonate) is an indole beta-adrenoceptor antagonist bearing a benzoyl ester residue on the beta-carbon atom of the propanolamine side chain. Bopindolol is metabolized by esterase to benzoic acid and an active metabolite, 18-502 [4-(3-t-butylamino-2-hydroxypropoxy)-2-methyl indole], which is further metabolized to 20-785 [4-(3-t-butylaminopropoxy)-2-carboxyl indole]. Bopindolol produces sustained blockade of beta 1- and beta 2-adrenoceptors, has intrinsic sympathomimetic as well as membrane stabilizing actions, inhibits renin secretion, and interacts with 5-HT receptors. Bopindolol is used in the treatment of hypertension. In limited trials bopindolol has also successfully reduced symptoms in patients with angina pectoris, anxiety and essential tremor.

Velnacrine (9-amino-1,2,3,4-tetrahydroacridin-1-ol) is an inhibitor of acetylcholinesterase. It was studied for the treatment of Alzheimer's disease however development was discontinued. There has been no research into the use of velnacrine as a cognitive enhancer in the treatment of Alzheimer's disease since 1994. The FDA peripheral and CNS drug advisory board voted unanimously against recommending approval. This review shows the toxic nature of velnacrine, and provides no evidence of efficacy.

Frentizole, a nontoxic antiviral and immunosuppressive agent, was used clinically in rheumatoid arthritis and systemic lupus erythematosus. Frentizole was more effective in suppressing human lymphocytes responding to Con A and PWM, than it was in cells activated by PHA, specific antigen, or alloantigen. Methylprednisolone, on the other hand, was more inhibitory for cells stimulated by PHA, specific antigen, or alloantigen. Frentizole, even at super immunosuppressive doses, does not predispose the hose (mice) to Pseudomonas aeruginosa, Candida albicans, herpes simplex virus, or Ann Arbor influenza virus. Frentizole is an inhibitor of the Aβ-ABAD interaction.

Roquinimex (Linomide, LS 2616) is a quinoline-3-carboxamide with pleiotropic immune modulating capacity and it has therapeutic effects in several experimental animal models of autoimmune diseases. Linomide has been evaluated in clinical trials for multiple sclerosis, and was indeed shown to have disease inhibitory effects. However, due to unexpected side effects recorded in patients treated with Linomide, premature termination of clinical trials was required. The basic mechanism(s) of action of Linomide in inducing beneficial effects in autoimmune diseases is still elusive. Some experimental evidence indicates that Linomide influences the regulation of the cytokine profile, resulting in the inhibition of autoimmune and inflammation pathologies. Roquinimex possesses potential antineoplastic activity. Roquinimex inhibits endothelial cell proliferation, migration, and basement membrane invasion; reduces the secretion of the angiogenic factor tumor necrosis factor alpha by tumor-associated macrophages (TAMs); and inhibits angiogenesis. Roquinimex was in phase III clinical trials with Pharmacia Corporation in Europe and the US for the treatment of multiple sclerosis.