Difference Between Omeprazole and Prevacid

Omeprazole and Prevacid are two drugs coming under the drug class category of proton pump inhibitors. Proton pumps are situated in mitochondrial membranes, which mean they are in all most all cells. The importance of these drugs is that they selectively inhibit proton pumps in the stomach lining. The mechanism of action is to inhibit H+/K+ ATPase enzyme selectively in gastric parietal cells. In the sense of organic chemistry, both these drugs are benzimidazoles containing substituted benzene ring and imidazole ring.


Omeprazole is also known by the trade names Prilosec and Zegerid. It is a proton pump inhibitor. This drug is prescribed to treat complications related to excessive acid secretion in the stomach such as damage to the esophagus and gastroesophageal reflux disease (GERD). This drug cannot render immediate relief from heartburns. The tablet should be taken 30 minutes before meals. The pill should be swallowed as a whole without chewing because it may damage the coating which is designed to protect the stomach. Granular suspension should be taken only with apple juice. Sometimes the granular suspension is delivered through nasogastric feeding tube.

There are a number of harmful effects of the drug. Animal studies have shown chronic usage may cause stomach cancers although it is not confirmed with humans up to the date. Tendency to increase bone fracture in hips, wrists, and spine is also found through clinical studies. Long term usage has shown to decrease the Vitamin B12 absorption and, therefore, cause B12 deficiency. Apart from all the harmful effects the drug also has various side effects associated. Uneven and fast heart rate, muscle weakness, diarrhea, coughing and choking, headache, and troubles in memory are some of the serious side effects. In addition weight change, stomach pain, insomnia is also experienced.

Omeprazole should not be taken if one is allergic to the drug. It should not be taken while under medication of other benzimidazole drugs. If a person is taking HIV AIDS medicine, ampicillin, blood thinner, water pills, iron tablets, diabetes medicine it is important to seek medical advice before taking Omeprazole.


Prevacid is also known by the generic name lansoprazole. This drug is used for the same complications related to excessive acid secretion in the stomach and diseases like Zollinger- Ellison syndrome. Prevacid and Omeprazole have a lot of similarities, but Prevacid could be given as a combination with antibiotics. Apart from the limitations stated under Omeprazole, Prevacid usage is limited if a person has suffered from liver disease or has low Magnesium levels in the blood. If a person is taking sucralfate (Carafate) while taking Prevacid, it is better to at least give a 30 minute gap between the intakes because sucralfate makes it difficult to get absorbed. The daily dosage of prevacid is 30mg and is larger than Omeprazole dosage of 20mg. The tendency of increasing bone fracture remains the same but decrease of vitamin B12 absorption is not confirmed. The rest of the details such as side effects, overdose effects are very similar.

What is the difference between Omeprazole (Prilosec) and Prevacid?

• Omeprazole is available with or without a prescription, but Prevacid requires a prescription.

• Daily dose of Omeprazole is 20mg, but daily dose of Prevacid is 30mg.

• Omeprazole is less expensive than Prevacid.