Vancomycin is a branched tricyclic glycosylated nonribosomal peptide produced by the fermentation of the Actinobacteria species Amycolatopsis orientalis (formerly Nocardia orientalis). Vancomycin became available for clinical use >50 years ago. It is often reserved as the "drug of last resort", used only after treatment with other antibiotics had failed. Vancomycin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections: Listeria monocytogenes, Streptococcus pyogenes, Streptococcus pneumoniae (including penicillin-resistant strains), Streptococcus agalactiae, Actinomyces species, and Lactobacillus species. The combination of vancomycin and an aminoglycoside acts synergistically in vitro against many strains of Staphylococcus aureus, Streptococcus bovis, enterococci, and the viridans group streptococci. The bactericidal action of vancomycin results primarily from inhibition of cell-wall biosynthesis. Specifically, vancomycin prevents the incorporation of N-acetylmuramic acid (NAM)- and N-acetylglucosamine (NAG)-peptide subunits from being incorporated into the peptidoglycan matrix; which forms the major structural component of Gram-positive cell walls. The large hydrophilic molecule is able to form hydrogen bond interactions with the terminal D-alanyl-D-alanine moieties of the NAM/NAG-peptides. Normally this is a five-point interaction. This binding of vancomycin to the D-Ala-D-Ala prevents the incorporation of the NAM/NAG-peptide subunits into the peptidoglycan matrix. In addition, vancomycin alters bacterial-cell-membrane permeability and RNA synthesis. There is no cross-resistance between vancomycin and other antibiotics. Vancomycin is not active in vitro against gram-negative bacilli, mycobacteria, or fungi.

Chloramphenicol is a broad-spectrum antibiotic that was first isolated from Streptomyces venezuelae in 1947. The drug was subsequently chemically synthesized. It has both a bacteriostatic and bactericidal effect; in the usual therapeutic concentrations it is bacteriostatic. Chloramphenicol is used for the treatment of serious gram-negative, gram-positive, and anaerobic infections. It is especially useful in the treatment of meningitis, typhoid fever, and cystic fibrosis. It should be reserved for infections for which other drugs are ineffective or contraindicated. Chloramphenicol, a small inhibitor of bacterial protein synthesis, is active against a variety of bacteria and readily enters the CSF. It has been used extensively in the last decades for the treatment of bacterial meningitis. In industrialized countries, chloramphenicol is restricted mostly to topical uses because of the risk of induction of aplastic anemia. However, it remains a valuable reserve antibiotic for patients with allergy to β-lactam antibiotics or with CNS infections caused by multiresistant pathogens.

Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent (Ia) in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duration, as well as a prolonged QT interval. Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (INa). Quinidine's effect on INa is known as a 'use-dependent block'. This means at higher heart rates, the block increases, while at lower heart rates, the block decreases. The effect of blocking the fast inward sodium current causes the phase 0 depolarization of the cardiac action potential to decrease (decreased Vmax). Quinidine also blocks the slowly inactivating, tetrodotoxin-sensitive Na current, the slow inward calcium current (ICA), the rapid (IKr) and slow (IKs) components of the delayed potassium rectifier current, the inward potassium rectifier current (IKI), the ATP-sensitive potassium channel (IKATP) and Ito. Quinidine is also an inhibitor of the cytochrome P450 enzyme 2D6 and can lead to increased blood levels of lidocaine, beta blockers, opioids, and some antidepressants. Quinidine also inhibits the transport protein P-glycoprotein and so can cause some peripherally acting drugs such as loperamide to have central nervous system side effects, such as respiratory depression if the two drugs are coadministered. Quinidine can cause thrombocytopenia, granulomatous hepatitis, myasthenia gravis, and torsades de pointes, so is not used much today. Torsades can occur after the first dose. Quinidine-induced thrombocytopenia (low platelet count) is mediated by the immune system and may lead to thrombocytic purpura. A combination of dextromethorphan and quinidine has been shown to alleviate symptoms of easy laughing and crying (pseudobulbar affect) in patients with amyotrophic lateral sclerosis and multiple sclerosis. This drug is marketed as Nuedexta in the United States. Intravenous quinidine is also indicated for the treatment of Plasmodium falciparum malaria. However, quinidine is not considered the first-line therapy for P. falciparum. The recommended treatments for P. falciparum malaria, according to the Toronto Notes 2008, are a combination of either quinine and doxycycline or atovaquone and proguanil (Malarone). The drug is also effective for the treatment of atrial fibrillation in horses.

QUALAQUIN (quinine sulfate) is an antimalarial drug indicated only for treatment of uncomplicated Plasmodium falciparum malaria. It’s an alkaloid derived from the bark of the cinchona tree and is the active ingredient in extracts of the cinchona that have been used for that purpose since before 1633. Quinine sulfate has been shown to be effective in geographical regions where resistance to chloroquine has been documented. Quinine inhibits nucleic acid synthesis, protein synthesis, and glycolysis in Plasmodium falciparum and can bind with hemazoin in parasitized erythrocytes. However, the precise mechanism of the antimalarial activity of quinine sulfate is not completely understood. It is thought to act by inhibiting heme polymerase, thereby allowing accumulation of its cytotoxic substrate, heme. As a schizonticidal drug, it is less effective and more toxic than chloroquine. Quinine is FDA-approved. It is not considered safe and effective for the treatment or prevention of leg cramps-- an "off-label" (non-FDA-approved) use. Quinine is associated with serious and life-threatening adverse events, including: thrombocytopenia, hypersensitivity reactions, and QT prolongation. Thrombocytopenia associated with the use of quinine for the treatment or prevention of leg cramps includes: immune thrombocytopenic purpura, hemolytic uremic syndrome, thrombotic thrombocytepenic purpura with associated renal insufficiency.

Methyl salicylate (or methyl 2-hydroxybenzoate), also known as wintergreen oil, is a natural product and is present in white wine, tea, porcini mushroom Boletus edulis, Bourbon vanilla, clary sage, red sage and fruits including cherry, apple, raspberry, papaya and plum. Methyl salicylate is topically used in combination with methanol and under brand name SALONPAS to temporarily relieves mild to moderate aches and pains of muscles and joints associated with: strains, sprains, simple backache, arthritis, bruises. The precise mechanism of action of methyl salicylate is not known, but there is suggested, that it cause dilation of the capillaries thereby increasing blood flow to the area.

Panulisib (P7170) was developed as a small molecule inhibitor of phosphatidylinositol 3-kinase (PI3K) and mTOR with potential anticancer activity. It is known that mTOR pathway is often upregulated in cancer and thus intensively pursued as a target to design novel anticancer therapies. P7170 were being tested in phase I clinical studies in patients with advanced refractory solid tumors. The primary objective was to determine the maximum tolerated dose and dose-limiting toxicity of the drug. However, this study is suspended because of the sponsor’s decision.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking, and is subsequently metabolically activated by cytochrome P4501A2 (CYP1A2) and N-acetyltransferase 2 (NAT2). PhIP has been used in trials studying the basic science of Pancreas Cancer.

Netazepide (YF476) is an orally active, benzodiazepine type, selective cholecystokinin B receptor (CCKBR; CCK2R; gastrin receptor) antagonist with potential gastric acid reducing and antiproliferative activity. Upon administration, netazepide, selectively binds to and blocks the CCKBR, thereby preventing the binding of gastrin and cholecystokinin. This may prevent gastric neuroendocrine enterochromaffin-like (ECL) cell-induced secretion of histamine, ultimately preventing gastric acid secretion from adjacent parietal cells. In addition, YF476 may inhibit ECL cell proliferation and ECL-derived gastric carcinoids. Netazepide has been used in trials studying the prevention and treatment of dyspepsia, hypergastrinaemia, barrett's esophagus, ECL-cell hyperplasia, and rebound hyperacidity, among others. Netazepide once daily for 12 weeks reduced the number of tumours and size of the largest one in 16 patients with autoimmune chronic atrophic gastritis (CAG), achlorhydria, hypergastrinaemia and multiple gastric neuroendocrine tumours (type 1 gastric NETs), and normalized circulating chromogranin A (CgA) produced by enterochromaffin-like cells, the source of the tumours.