Excess stomach acid secretion plagues many people and likely has for eons. Heartburn is the most common problem it causes.

We’ll get the hard stuff out of the way first, so hold on to your coffee cup.

In stomach lining, the parietal (pah-RYE-e-tal) cells make and secrete the hydrochloric acid that aids digestion. The acids are stimulated by histamine, which is produced by hormone secreting cells, and two other substances called gastrin, a hormone from other stomach cells, and acetycholine (a-si-till-ko-leen). It’s actually more complicated than this.

OK, take another sip. Science class is over.

The best illustration of acid problem prevalence is the quantity of antacids that have been swigged and chewed for decades in the form of Tums, Mylanta, etc. They were sort of effective but not very.

In 1964 it was established that histamine stimulated secretion of stomach acid, but traditional antihistamines had no effect on it. Researchers at the drug company Smith, Kline, and French synthesized hundreds of compounds until they found one in the late 1960s called cimetidine (sigh-MET-ih-deen) that worked well.

It was marketed as Tagamet, and it became the first “blockbuster” drug ever. It was followed soon by ranitidine, a modified form of cimetidine made by Glaxo, which was 10 times more active than cimetidine and had fewer drug interactions.

These, plus famotidine and nizatidine, two competitors, work by blocking histamine from binding to parietal cells. Called H-2 blockers, they work only partially at acid suppression because gastrin and acetycholine aren’t blocked.

The search for turned up proton pump inhibitors, which stop up to 99 percent of acid secretion before it gets into the stomach. A parietal cell enzyme system (hydrogen/potassium ATPase that is the gastric proton pump) secretes the proton hydrogen for the acid. The proton pump inhibitors bind to this enzyme and inactivate it until the cell’s nucleus can make a new copy to replace it.

The first proton pump inhibitor was omeprazole (brand Prilosec). It was the best-selling drug for a few years. It was followed quickly by competitors lansoproazole (Prevacid), and pantoproazole (Protonix). When Prilosec became generic, a slightly different form, esomeprazole, was sold as Nexium, which even outsold Viagra (though for other obvious reasons). These and others have largely supplanted the H-2 blockers as favored treatments for heartburn, gastroesophageal reflux (backwash of acid into esophagus — major league heartburn) and stomach/small bowel ulcer disease.

They actually help heal these problems and are generally considered effective and safe.

The problem with proton pump inhibitors is that vitamin B-12 and especially calcium are less well absorbed. With long-term proton pump inhibitor use, they should be supplemented.

Why go through this long discussion? It’s because we now have most of these, which previously required prescriptions, being sold over the counter at lower doses. We have to be the doctor and make choices.

Usually our personal result will determine our choice whether we need these medicines. The proton pump inhibitors Prilosec and Prevacid can have different results for individuals. When sold over-the-counter, they are half the prescription doses. Zantac and Tagamet as H-2 blockers are likewise half dosage. Should you take one of each? Probably not for health reasons.

The ads are all over-hyped. If a particular drug stops bad heartburn or stomach pain, it is valuable. You may have to try a couple to compare. The proton pump inhibitors are likely better for most. But, taking calcium with them is a good addition.

Protons are the part of an atom with the plus sign. Two atoms meet on the street. One says that he lost an electron. The other asks, “Are you positive?” Get it?

Frank Bures is a dermatologist in Winona.