How would Prilosec, which decreases acid production, cause excessive belching, which it does . . .?

it's a sulphur, that's why

Omeprazole (INN) (pronounced /oʊˈmɛprəzoʊl/) is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease (PUD), gastroesophageal reflux disease (GORD/GERD) and Zollinger-Ellison syndrome. It was first marketed in the US in 1989 by AstraZeneca under the brand names Losec and Prilosec, and is now also available from generic manufacturers under various brand names. AstraZeneca markets omeprazole as Losec, Antra, Gastroloc, Mopral, Omepral, and Prilosec. Omeprazole is marketed as Zegerid by Santarus, Prilosec OTC by Procter & Gamble and Zegerid OTC by Schering-Plough.[3][4] Omeprazole is one of the most widely prescribed drugs internationally and is available over the counter in some countries. Prilosec contains the active ingredient omeprazole and Prilosec OTC contains the active ingredient omeprazole magnesuim.

Contents [hide]

1 Pharmacology

2 Name change

3 Clinical use

3.1 Use in Helicobacter pylori eradication

4 Dosage forms

4.1 Multiple unit pellet system

4.2 Immediate release formulation

5 Side effects

6 Interactions

7 Absorption and distribution

8 Metabolism and excretion

9 References

[edit] Pharmacology

Omeprazole is a racemate. It contains a tricoordinated sulfur atom in a pyramidal structure and therefore can exist in equal amounts of both the S and R enantiomers. In the acidic conditions of the stomach, both are converted to achiral products, which reacts with a cysteine group in H+/K+ ATPase, thereby inhibiting the ability of the parietal cells to produce gastric acid.