Magnesium Hydroxide/Omeprazole/Sodium Bicarbonate

Nocturnal gastro‐oesphageal reflux is an under‐appreciated clinical challenge. This condition may cause symptoms such as nocturnal heartburn, or it may be asymptomatic. In addition, patients may experience sleep disturbances that can potentially lead to complications such as erosive oesophagitis and Barrett's oesophagus, and may be a risk factor for development of oesophageal adenocarcinoma. Delayed‐release proton‐pump inhibitors (PPIs) have traditionally been effective in treating both daytime and night‐time reflux symptoms, but are limited in control of nocturnal acidity by their pharmacodynamic characteristics.This narrative review addresses the prevalence, impact and pharmacologic approaches used to control nocturnal acidity. Methods to optimize nocturnal acid control include careful attention to dosing schedule, using higher doses of PPIs, adding an histamine H2‐receptor antagonist at bedtime to once or twice daily delayed‐release PPI, or using immediate‐relase omeprazole (Zegerid powder for oral suspension; Santarus, Inc., San Diego, CA, USA).This new formulation appears to provide sustained control of intragastric pH at steady state, and when dosed at bedtime, and may be effective in improving control of nocturnal pH and treating night‐time GERD.

The absorption of most oral proton‐pump inhibitors is delayed by the enteric coating required to protect the acid‐labile proton‐pump inhibitor from degradation in the stomach and, as a result, antisecretory effect is also delayed.This article provides an overview of the pharmacokinetics and pharmacodynamics of a new immediate‐release omeprazole [(IR‐OME) Zegerid power for oral suspension; Santarus Inc., San Diego, CA, USA] and its potential advantages over delayed‐release proton‐pump inhibitors.Immediate‐release omeprazole has a higher mean peak plasma omeprazole concentration (Cmax) and a significantly shorter mean time to reach Cmax (tmax) than delayed‐release omeprazole. Immediate‐release omeprazole 40 mg has a prolonged antisecretory effect with median intragastric pH above 4.0 for 18.6 h/day at steady‐state, after 7 days of once daily dosing. The sodium bicarbonate in immediate‐release omeprazole protects the uncoated omeprazole from degradation by gastric acid. The accelerated antisecretory action of immediate‐release omeprazole compared with delayed‐release omeprazole may be due to the activation of proton pumps by the rapid neutralization of intragastric acid by the sodium bicarbonate. The faster onset of action seen with immediate‐release omeprazole is not achieved by using an antacid with a delayed‐release proton‐pump inhibitor, because administering antacids with conventional delayed‐release proton‐pump inhibitors does not significantly enhance absorption of the proton‐pump inhibitor.In conclusion, immediate‐release omeprazole is associated with rapid absorption of omeprazole and rapid onset of antisecretory effect, without compromising the duration of acid suppression.