Proton pump inhibtors (PPIs) work by directly switching off the acid pumps, which live on the surface of the stomach’s acid producing cells, the ‘parietal cells’.
There are five drugs in the PPI class. They are Omeprazole, Lansoprazole, Rabeprazole, Pantoprazole and Esomeprazole.
All these drugs have similar strength (potency), although studies suggest that Esomeprazole (Nexium) may be more powerful than the others at equivalent doses.
How do PPIs work?
New tiny acid pumps (also known as proton pumps) are made by these cells each time a person eats. The more one eats, the more pumps that are made. These pumps create hydrochloric acid and pump it into the body of the stomach where it helps break down the food. They also help to kill any bacteria in the food.
Why does the stomach make acid?
Scientists think that one of the main roles of stomach acid during evolution was to sterilise food before it entered the gut. The need for this has been mostly removed now as most of the food we eat is clean and not infected. In addition, we cook or pickle those foods most at risk of harbouring dangerous bacteria such as meat and fish.
The best time to take PPI medicines
PPIs irreversibly bind the pumps, rendering them useless. New pumps will be made next time the person eats. PPIs exert their effects most strongly in the 30-60 minutes after they are taken, so they have maximum effect if they are swallowed a little while before eating. Overall, these drugs tend to render the stomach acid free for around 12 hours.
Usually, removing acid from the stomach for 12 hours per day, particularly during the daytime, is enough to reduce the acid reflux so that the inflammation that has been caused to the oesophagus can settle. In a small number of people, it is necessary to take the pills twice a day. This allows for the stomach to be free of acid for the entire 24 hour period. Doing this allows inflammation to heal in those people whereas once daily dosing was not adequate.
Are there risks in removing acid from the stomach?
Some people are worried that removing the acid from the stomach can have harmful effects. Click here to find out whether they are right.
In summary, proton pump inhibitors are powerful and effective and large numbers of people find that they need to take them regularly.