How do proton pump inhibitors work? A look at their mechanism of action
Proton pump inhibitors are a class of drug which includes omeprazole (the most commonly used variant) that is used in cases of gastric irritation. Mainly, proton pump inhibitors such as omeprazole are given to those with gastric reflux disease, a condition whereby there is an increased level of gastric acid than is normal.
This build up can cause a wide array of conditions, from heart burn to severe gastric tract irritation which, if left untreated can cause more serious complications such as ulceration of the gastric tract. Therefore, proton pump inhibitors are highly important drugs. Thankfully, the way they work is fairly straightforward with their mechanism of action being uncomplicated.
Proton pump inhibitors are initially inactive when given to a patient. This is done so that it can enter the secretory canaliculus. Here, due to it being acidic, the PPI undergoes protonation to become active. After this, the hydrogen/potassium adenosine triphosphatase system is irreversibly inhibited.
The significance of this is that this system is found in the parietal cells and is responsible for the release of hydrogen ions which are otherwise responsible for the production of hydrochloric acid, the main culprit in the aforementioned diseases. Further, unlike other antagonists that can revert a system back to its previous state when the drug is withdrawn, this is not the case for PPI’s.
Due to the fact that the irreversible inhibition is brought about by the denaturing of the parietal cells of the aforementioned system, the only way that further hydrogen ions can be generated is through the production of new cells within the gastric system. This is normally not normally an overnight occurrence, thus it is regarded as irreversible. However, after treatment has been terminated, it is normally fine for the patient to not have a subsequent course of PPI’s.
As you can see, the mechanism of action of omeprazole and other PPI’s is very simplistic, and yet the way it works is also extremely effective in aiding those with gastric problems.