Omeprazole belongs to a class of antisecretory compounds, which suppress gastric acid secretion by specific inhibition of the H+ /K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. Because this enzyme system is regarded as the acid (proton) pump within the gastric mucosa, omeprazole has been characterized as a gastric acid-pump inhibitor, in that it blocks the final step of acid production. This effect is dose-related and leads to inhibition of both basal and stimulated acid secretion irrespective of the stimulus. Omeprazole is used under brand names Prilosec and Losec for treatment of duodenal ulcer in adults, gastric ulcer in adults, Gastroesophageal Reflux Disease. In addition it used for maintenance of healing of erosive esophagitis in pediatric patients and adults and for treatment of pathological hypersecretory conditions in adults (eg, Zollinger-Ellison syndrome, multiple endocrine adenomas and systemic mastocytosis). The most frequent significant adverse effects occurring in at least of patients include headache; upper respiratory tract infection, abdominal pain, diarrhea, back pain, weakness and rash.

Apalutamide (developmental code name ARN-509) is a selective and competitive androgen receptor inhibitor with IC50 of 16 nM, useful for prostate cancer treatment. Apalutamide binds to AR in target tissues thereby preventing androgen-induced receptor activation and facilitating the formation of inactive complexes that cannot be translocated to the nucleus. This prevents binding to and transcription of AR-responsive genes. This ultimately inhibits the expression of genes that regulate prostate cancer cell proliferation and may lead to an inhibition of cell growth in AR-expressing tumor cells. Apalutamide is currently in phase III clinical trials for castration-resistant prostate cancer.

Clarithromycin is an antibacterial drug which is used either in combination with lansoprazole and amoxicillin (Prevpac), in combination with omeprazole and amoxicillin (Omeclamox) or alone (Biaxin) for the treatment of broad range of infections. The drug exerts its action by binding to 23s rRNA (with nucleotides in domains II and V). The binding leads to the protein synthesis inhibition and the cell death.

Esomeprazole strontium is a proton pump inhibitor. It suppresses gastric acid secretion by specific inhibition H+/K+ ATPase in the gastric parietal cell. The S- and R-isomers of omeprazole are protonated and converted in the acidic compartment of the parietal cell forming the active inhibitor, the achiral sulphenamide. By acting specifically on the proton pump, esomeprazole blocks the final step in acid production, thus reducing gastric acidity. The drug is indicated for the treatment of gastroesophageal reflux disease, reduction the risk of NSAID-associated gastric ulcer, eradication of H.pylori, and pathological hypersecretory conditions.

Omeprazole belongs to a class of antisecretory compounds, which suppress gastric acid secretion by specific inhibition of the H+ /K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. Because this enzyme system is regarded as the acid (proton) pump within the gastric mucosa, omeprazole has been characterized as a gastric acid-pump inhibitor, in that it blocks the final step of acid production. This effect is dose-related and leads to inhibition of both basal and stimulated acid secretion irrespective of the stimulus. Omeprazole is used under brand names Prilosec and Losec for treatment of duodenal ulcer in adults, gastric ulcer in adults, Gastroesophageal Reflux Disease. In addition it used for maintenance of healing of erosive esophagitis in pediatric patients and adults and for treatment of pathological hypersecretory conditions in adults (eg, Zollinger-Ellison syndrome, multiple endocrine adenomas and systemic mastocytosis). The most frequent significant adverse effects occurring in at least of patients include headache; upper respiratory tract infection, abdominal pain, diarrhea, back pain, weakness and rash.

Metronidazole was synthesized by France's Rhone-Poulenc laboratories and introduced in the mid-1950s under the brand name Flagel in the US, while Sanofi-Aventis markets metronidazole globally under the same trade name, Flagyl, and also by various generic manufacturers. Metronidazole is one of the rare examples of a drug developed as ant parasitic, which has since gained broad use as an antibacterial agent. Metronidazole, a nitroimidazole, exerts antibacterial effects in an anaerobic environment against most obligate anaerobes. Metronidazole is indicated for the treatment of the following infections due to susceptible strains of sensitive organisms: Trichomoniasis: symptomatic, asymptomatic, asymptomatic consorts; Amebiasis: acute intestinal amebiasis (amebic dysentery) and amebic liver abscess; Anaerobic bacterial infections; Intra-abdominal infections, including peritonitis, intra-abdominal abscess, and liver abscess; Skin and skin structure infections; Gynecologic infections, including endometritis, endomyometritis, tubo-ovarian abscess, and postsurgical vaginal cuff infection; Bacterial septicemia; Bone and joint infections, as adjunctive therapy; Central Nervous System infections, including meningitis and brain abscess; Lower Respiratory Tract infections, including pneumonia, empyema, and lung abscess; Endocarditis. Metronidazole is NOT effective for infections caused by aerobic bacteria that can survive in the presence of oxygen. Metronidazole is only effective against anaerobic bacterial infections because the presence of oxygen will inhibit the nitrogen-reduction process that is crucial to the drug's mechanism of action. Once metronidazole enters the organism by passive diffusion and activated in the cytoplasm of susceptible anaerobic bacteria, it is reduced; this process includes intracellular electron transport proteins such as ferredoxin, transfer of an electron to the nitro group of the metronidazole, and formation of a short-lived nitroso free radical. Because of this alteration of the metronidazole molecule, a concentration gradient is created and maintained which promotes the drug’s intracellular transport. The reduced form of metronidazole and free radicals can interact with DNA leading to inhibition of DNA synthesis and DNA degradation leading to death of the bacteria. The precise mechanism of action of metronidazole is unknown. Metronidazole has a limited spectrum of activity that encompasses various protozoans and most Gram-negative and Gram-positive anaerobic bacteria. Metronidazole has activity against protozoans like Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis, for which the drug was first approved as an effective treatment.

Pumaprazole is imidazopyridine derivative patented by Byk Gulden Lomberg Chemische Fabrik GmbH for the treatment of gastrointestinal diseases. Pumaprazole acts as a reversibly binding acid pump antagonist. Pumaprazole differs from covalently binding proton pump inhibitors (PPIs), such as omeprazole, both with respect to chemical structure and mode of interaction with the gastric H(+)/K(+)-ATPase. In preclinical models, the single dose of Pumaprazole is able to elevate intragastric pH in the dog with gastric fistula under pentagastrin or carbachol stimulation from pH 1 to about pH 7 while still displaying a dose-dependent, well-controllable duration of action of a few hours.

Ufiprazole (Omeprazole sulfide) is a metabolite of Omeprazole, which is a proton pump inhibitor. Omeprazole sulfide has been shown to be a direct-acting inhibitor of CYP2C19 in pooled human liver microsomes. Ufiprazole is also a weak BRS-3 agonist.