Medication
There are 4 major classes of drugs to treat the acid element of acid reflux.
In ascending order of effectiveness, they are antacids, alginates, H2 blockers and Proton Pump Inhibitors and Potassium Combative Acid Blockers.
If you need to use any of these drugs frequently,
please seek medical advice.
Antacids
These work immediately on excess acid in the oesophagus. They do not prevent acid reflux occurring.
They are drugs that neutralise the acid. Most commonly they are made of chalk, calcium carbonate. Examples are Tums or Rennie. Chemically, this reaction takes place:
Chalk (calcium carbonate) based. Examples are Tums or Rennie. Chemically, this reaction takes place:
CaCO3 + 2HCl → CaCl2 + H2O + CO2
(Calcium Carbonate + Hydrochloric acid gives Calcium Chloride (a harmless salt) plus water and carbon dioxide).
Warning. Excess calcium is filtered out of the blood by the kidneys where it may accumulate to form kidney stones. Excess calcium can also lead to calcification of the arteries which can cause myocardial infarction, heart attack.
Baking Soda (Sodium Bicarbonate) based, Example Alka Seltzer.
NaHCO3 + HCl → NaCl + H2O + CO2
(Sodium bicarbonate (baking soda) + Hydrochloric (stomach) acid gives Sodium Chloride (common table salt) plus water and carbon dioxide gas).
Warning. Too much sodium in the diet can lead to high blood pressure, heart disease, and stroke.
Alginates
Gaviscon is the brand name of the white milky liquid that floats on the stomach contents as oil floats on water to reduce the possibility of reflux whilst also providing a temporary protective film to the lower oesophagus and neutralising the acid with an antacid component. (Some generic versions are now available, such as Peptac.)
This old UK TV advert, remembered by many, shows how it works.
H2 blockers
Histamine H2 Receptor Antagonists work to block the (histamine H2) signals that tell the stomach to produce acid. (N.B. This is not the same as an antihistamine which blocks histamine H1).
These work proactively to reduce the amount of acid by preventing histamine signals reaching the parietal cells telling them to make acid. They are not an instant antacid and are often prescribed to be taken in the evening to reduce nighttime acid.
(Other H2 blockers: Lafutidine, Loxtidine, Niperotidine, Roxatidine.)
* Please note doses shown are not guaranteed to be equivalent. Do not assume because a dose is shown it is the safe dose. It may vary according to age and body build.
In 2019, some batches of Zantac were found to have a higher level of NDMA than they should. Although there is no evidence to prove it, NDMA (N-nitroso dimethylamine) is thought to be carcinogenic. Ranitidine was removed from the shelves. The levels of NDMA found, however, were no higher than found on grilled meat. Further investigaton showed the samples were tainted by incorrect storage.
This paper from February 2023 ruled out any cancer risk. Study rules out link between use of ranitidine & cancer risk.
"The recent study provided no evidence of the association of NDMA impurities in ranitidine products with cancer risk, which further substantiates the US district court findings in which the Florida court dismissed almost 2,500 lawsuits alleging links between heartburn medication Zantac (Ranitidine) and cancer. The judge had said that almost 2,500 lawsuits filed in federal court by plaintiffs were based on flawed science and that the only reliable testing of the blockbuster drug undertaken showed an ‘unprovable risk of cancer’."
Proton Pump Inhibitors (PPIs)
(Other PPIs: Ilaprazole, Picoprazole, Tenatoprazole, Timoprazole)
Do not assume because a dose is shown it is the safe dose. It may vary according to age and body build.
The most common brand names are shown though they may also be known under other names in other parts of the world.
Research evidence has shown all PPIs are as effective as each other (though the drugs companies may try to make us believe otherwise) but some may be better tolerated by some patients. [a-iv][a-v]
* Astra Zeneca (who make the drug) claims 40mg esomeprazole is equivalent to 20mg omeprazole and one (Astra Zeneca sponsored) trial showed 40mg esomeprazole was better at reducing acid production than 20mg omeprazole. [a-vi]
Another study published February 2015 [a-vii] also compared 40mg esomeprazole with 30mg lansoprazole and 40mg Pantoprazole finding: "esomeprazole was more effective".
Research funded by Reckitt Benkiser (who make the drug) found Gaviscon was no less effective than standard dose omeprazole for a 24hr period. [a-viii]
How PPIs work
PPIs target the final step of acid production in the stomach, directly inhibiting the enzyme responsible for secreting gastric acid. The process can be broken down into several key steps:
Parietal Cells and the Proton Pump: The stomach's parietal cells are specialized cells that secrete hydrochloric acid (HCl) into the body of the stomach. These cells contain proton pumps, specifically the H+/K+ ATPase enzyme, located on the cell membrane. This enzyme is crucial for acid production as it exchanges hydrogen ions (H+) from the parietal cells with potassium ions (K+) from the stomach, resulting in acid secretion.
Activation of PPIs: PPIs are initially inactive, lipophilic prodrugs. After oral ingestion, they travel through the bloodstream and accumulate in the acidic environment of the parietal cells. Once in this acidic environment, PPIs undergo chemical conversion to their active form, a sulfenamide derivative.
Inhibition of the Proton Pump: The activated PPI covalently binds to cysteine residues on the H+/K+ ATPase enzyme. This binding irreversibly inhibits the proton pump's activity, effectively blocking the secretion of hydrogen ions into the stomach. By inhibiting these pumps, PPIs dramatically reduce gastric acid production.
Potassium Competitive Acid Blockers (PCABs)
Similar to PPIs, the first PCAB is Vonoprazan.
This paper in Gastrointestinal Pharmacology and Therapeutics from 2018 provides a very good initial overview: Potassium-competitive acid blockers - are they the next generation of proton pump inhibitors?
"There have been tremendous changes in the treatment of acid-related diseases. In this rapidly evolving field, novel drugs such as potassium-competitive acid blockers (P-CABs) show promising potential. This review aims to provide a perspective on this new class of drugs by summarizing the mechanism of action, therapeutic benefits, adverse effects and approval status of various P-CABs in the market."
This study was published in Medical Science Monitor in 2019: Comparison of the Use of Vonoprazan and Proton Pump Inhibitors for the Treatment of Peptic Ulcers Resulting from Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis
"The findings of the systematic review and meta-analysis showed that the efficacy of vonoprazan was comparable with PPIs for the treatment of peptic ulcers following ESD. Further studies are required to support the safety and efficacy of vonoprazan compared with different types of PPIs. "
This study was published in Gastroenterology in October 2022: "Vonoprazan versus Lansoprazole for Healing and Maintenance on Healing of Erosive Esophagitis: A Randomized Trial"
"Vonoprazan was non-inferior and superior to the PPI lansoprazole in healing and maintenance of healing of erosive esophagitis. This benefit was seen predominantly in more severe erosive esophagitis."
A study published in Cureus in 2024 reviewed papers and randomised controlled trials comparing PPIs and PCABs, concluding, "This meta-analysis demonstrates that PCABs are more effective than PPIs in healing Erosive Esophagitis and resolving heartburn symptoms in patients with GERD. PCABs showed a higher rate of healing and symptom relief while maintaining a safety profile comparable to PPIs. The superior efficacy of PCABs can be attributed to their unique pharmacological properties, allowing for enhanced acid suppression. However, long-term safety data for PCABs are still limited."
PCABs and Cancer?
Whether or not PCABs demonstrate a similar chemo-protective benefit to PPIs is yet to be determined.
This link directs to a page examining the claims for and against long term use of PPI medication.
Page updated 22 July 2024