Aspirin is a nonsteroidal anti-inflammatory drug. Aspirin is unique in this class of drugs because it irreversibly inhibits both COX-1 and COX-2 activity by acetylating a serine residue (Ser529 and Ser516, respectively) positioned in the arachidonic acid-binding channel, thus inhibiting the synthesis of prostaglandins and reducing the inflammatory response. The drug is used either alone or in combination with other compounds for the treatment of pain, headache, as well as for reducing the risk of stroke and heart attacks in patients with brain ischemia and cardiovascular diseases.

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.

Etanidazole (also known as Radinyl) is a 2-nitroimidazole with radiosensitizing properties. Etanidazole exerts its therapeutic action by depleting glutathione and inhibiting glutathione S-transferase, thus enhancing the anticancer effects of radiation therapy. Etanidazole was tested in Phase III clinical trials in patients with advanced head and neck cancer, however, its development was stopped. A fluorinated etanidazole (EF5) may also be useful as an imaging agent for identification of hypoxic, drug-resistant regions of primary tumors and metastases.

Exisulind (tentative trade name Aptosyn) is an antineoplastic agent, which was originally developed by Cell Pathways. This drug is an inhibitor of phosphodiesterase (PDE) isozymes: PDE5 and PDE4. Inhibition of PDE5 appears to be pharmacologically relevant, which leads to increase cGMP and activate protein kinase G at doses that induce apoptosis, whereas cyclic AMP levels were not changed. Exisulind has been in phase III clinical trials for the treatment of Non-Small Cell Lung Cancer and for the treatment of polyps in patients who have familial adenomatous polyposis (Colorectal Cancer and Small Intestine Cancer). In addition, this drug was in phase II/III for the treatment of Prostate Cancer, however, there studies have been discontinued.

Etazolate (EHT-0202) is a selective, positive GABAA receptor modulator has completed phase II clinical trials in patients with Alzheimer's disease. It is also a selective phosphodiesterase-4 inhibitor that is specific for cAMP. Etazolate showed anxiolytic and antidepressant activity and could be useful in managing post-traumatic stress disorder.

Tarenflurbil (Flurizan or R-flurbiprofen) is the single enantiomer of the racemate NSAID flurbiprofen. Tarenflurbil is a first in class, selective amyloid-beta42 (A42) lowering agent (SALA), which acts by modulating the activity of gamma-secretase, an enzyme that converts amyloid precursor protein to amyloid-beta. The reduction of A42 may prevent the development of the amyloid plaques thought to be a key pathological process associated with Alzheimer’s disease. For several years, research and trials for the drug were conducted by Myriad Genetics, to investigate its potential as a treatment for Alzheimer's disease. In a brief statement issued June 30, Myriad Genetics reports that tarenflurbil (Flurizan) failed to have a significant effect in a phase 3 trial of patients with mild Alzheimer's disease (AD). The failure of Flurizan™ is generally attributed to its insufficient pharmacodynamics, i.e., inadequate ability to penetrate the brain and engage its target protein at doses sufficient to yield an effect. Two additional Phase 3 trials were terminated and further development of Flurizan™ was discontinued. Separate clinical development of Flurizan™ for prostate cancer has also been discontinued following negative Phase 2 results. Tarenflurbil activates c-Jun N terminal kinase, increases AP-1 binding to DNA, and downregulates cyclin D1 expression, resulting in the arrest of tumour cells in the G1 phase of the cell cycle and apoptosis. This agent also affects the expression of nuclear factor kappa B, a rapid response transcription factor that stimulates the immune response to tumour cells. Tarenflurbil does not inhibit the enzyme cyclooxygenase. The Fraunhofer Institute for Molecular Biology and Applied Ecology is currently developing tarenflurbil for the treatment of relapsing, remitting multiple sclerosis.

Dacinostat (also known as LAQ824), is a hydroxamate histone deacetylase inhibitor with potential anticancer activity. Dacinostat inhibits histone deacetylase enzymatic activities in vitro and transcriptionally activated the p21 promoter in reporter gene assays. Tumor cells treated with Dacinostat caused acetylation of HSP90 and degradation of its cargo oncoproteins. Flow cytometry studies revealed that both tumor cell lines and normal diploid fibroblasts arrested in the G2/M phase of the cell cycle after Dacinostat treatment. However, an increased sub-G1 population at 48 h (reminiscent of apoptotic cells) was only observed in the cancer cell lines treated with Dacinostat. Dacinostat exhibited antitumor effects in a xenograft animal models. In phase I trials, Dacinostat was well tolerated at doses that induced accumulation of histone acetylation, with higher doses inducing changes consistent with HSP90 inhibition. In another phase 1 in patients with advanced solid tumors, grade 3 or 4 toxicities were observed. Dacinostat had been in phase II clinical trials by Novartis for the treatment of solid tumors but further studies were discontinued.

Plinabulin (formerly known as NPI-2358) is a potent microtubule-destabilizing agent that exerts its effect by binding to the colchicine-binding site of tubulin. Plinabulin projects its potent antitumor activity against a broad spectrum of tumor cell lines. This drug in combination with docetaxel is under development by BeyondSpring Pharmaceuticals in a worldwide Phase 3 clinical trial for non-small cell lung cancer. Pegfilgrastim is also in phase II clinical trial for the prevention of chemotherapy-induced neutropenia, where docetaxel, doxorubicin, and cyclophosphamide (TAC) were used as the chemotherapy. Plinabulin also possessed antitumor activity in animal models with multiple myeloma cancer cells, where the JNK protein appeared to be a primary target of plinabulin.

Ravuconazole is a triazole with antifungal properties that inhibits cytochrome P450 sterol 14a-demethylase, an enzyme involved in sterol synthesis, resulting in lysis of the fungal cell wall and fungal cell death. It was investigated for the treatment of aspergillosis, candidiasis, and onychomycosis, but these studies were discontinued. Ravuconazole is now in phase II clinical trials to investigate efficacy in preventing fungal infections in patients undergoing chemotherapy and stem cell transplantation.

Sulrnazole (the former AR-L 115 BS) is a benzimidazole derivative with positive inotropic, positive chronotropic and vasodilator effects. Sulrnazole also has been shown to improve cardiac index and reduce pulmonary capillary wedge pressure without significant change in heart rate or arterial pressure. Intravenous administration caused a 217 per cent increase in cardiac output with a 25 per cent decrease in pulmonary wedge pressure. Short-term oral administration resulted in a 317 per cent increase in cardiac index and a 317 per cent increase in ejection fraction. Side effects have included visual blurring and transient colour blindness. Sulmazol has been demonstrated to improve regional wall motion in patients with ischemic heart disease and to abolish pacing-induced ischemia. Sulrnazole is an A1 adenosine receptor antagonist. It is also a phosphodiesterase inhibitor.