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.

Adenosine is a nucleoside that is composed of adenine and d-ribose, occurring in all cells of the body and play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter. Adenocard (adenosine injection) is used as an initial treatment for the termination of paroxysmal supraventricular tachycardia (PVST), including that associated with accessory bypass tracts (Wolff-Parkinson-White Syndrome). When clinically advisable, appropriate vagal maneuvers. Adenocard does not convert atrial flutter, atrial fibrillation, or ventricular tachycardia to normal sinus rhythm. In the presence of atrial flutter or atrial fibrillation, a transient modest slowing of ventricular response may occur immediately following Adenocard administration. Adenosine slows conduction time through the A-V node, can interrupt the reentry pathways through the A-V node, and can restore normal sinus rhythm. This effect may be mediated through the drug's activation of cell-surface A1 and A2 adenosine receptors. Adenocard is antagonized competitively by methylxanthines such as caffeine and theophylline, and potentiated by blockers of nucleoside transport such as dipyridamole. Adenocard is not blocked by atropine. Adenosine also inhibits the slow inward calcium current and activation of adenylate cyclase in smooth muscle cells, thereby causing relaxation of vascular smooth muscle. By increasing blood flow in normal coronary arteries with little or no increase in stenotic arteries, adenosine produces a relative difference in thallous (thallium) chloride TI 201 uptake in myocardium supplied by normal verus stenotic coronary arteries.

Phenobarbital is a barbiturate derivative used to treat insomnia and anxiety, seizures, hyperbilirubinemia in neonates and cholestasis. Phenobarbital promotes binding to inhibitory gamma-aminobutyric acid subtype receptors, and modulates chloride currents through receptor channels.

Denufosol is a novel second-generation, metabolically stable, selective P2Y(2) receptor agonist. As ion channel regulator denufosol corrects the ion transport defect and increases the overall mucociliary clearance in cystic fibrosis (CF) lung disease by increasing chloride secretion, inhibiting sodium absorption, and increasing ciliary beat frequency in the airway epithelium independently of cystic fibrosis transmembrane conductance regulator genotype. Denufosol improved lung function relative to placebo in cystic fibrosis patients with normal to mildly impaired lung function. The drug half-life is 25 hours in ex vivo CF sputum and 3 hours when added in vitro to human respiratory epithelial cultures. Denufosol has been generally well-tolerated in healthy volunteers and patients with cystic fibrosis. The most common adverse events were in the respiratory system, with cough having the highest frequency.