Text: Bertrand Tappy

Every molecule tells a story: omeprazole

A short biography of omeprazole, the “golden boy” drug of the pharmaceutical industry in the 1990s.

Whether caused by the food we eat, our lifestyle or our genetic make-up, excess stomach acid might seem to be a condition of our times. The number of ads boasting the merits of drugs and other therapies used to treat heartburn also show that it is a highly lucrative market.

However, the problem has been around for decades. The only difference is that doctors were unable to control acid production in the stomach as well. “In the 1960s, antihistamines such as cimetidine and ranitidine were used to regulate gastric acid,” says Thierry Buclin of the Clinical Pharmacology Division at Lausanne University Hospital (CHUV). “But these drugs did not always produce the desired results. If it developed into an ulcer, the only alternative at the time was surgery.”

The situation changed radically in the 1990s with the introduction of omeprazole. This drug took a novel approach by directly inhibiting the mechanism responsible for producing gastric acid, known as the “proton pump”. Sold by Astra (since renamed AstraZeneca) after several years of development, it rapidly became the best-selling product in the history of the pharmaceutical industry.
“Its launch was tremendous,” says Thierry Buclin. “Given its unquestionable effectiveness and low risk of side effects, many physicians started prescribing it at the slightest mention of gastric trouble.”

We now know that things are not so simple. “The drug still improves day-to-day life for the thousands of patients who really need it,” says Thierry Buclin. “But it has recently been established that omeprazole can not only damage the bones and respiratory tract but can also cause a form of addiction in regular users. As long as they take the medication, their stomach still tries to produce acid, despite the inhibition,” he explains. “When patients stop taking omeprazole, the stimulation persists and acid is secreted in higher amounts than before! They become convinced that they constantly need the drug.” Captive customers obviously guarantee long-term gains for the producer.

But the patent expired in the early 2000s, and a tidal wave of generics came from the competition. Fortunately, Astra still had one more star: esomeprazole, a simplified version of the molecule claimed to be even more effective. “But we still have to wonder what its real benefits are, apart from providing the firm with a new patent” says Thierry Buclin.