Worried about side effects of antibiotics

Q: During a routine health check, my wife's test results showed the presence of helicobacter pylori bacteria in her gut. She was prescribed amoxycillin, clarithromycin and olit.

My wife has never had any stomach ulcers. While browsing online, I learnt that two-thirds of the world's people have this bacteria in their stomachs. Up to 85 per cent of those infected never experience symptoms or complications, and the bacteria may play an important role in the natural stomach ecology.

As the bacteria has been around for many years and is so widespread, is it possible that it has already become drug-resistant? Should my wife leave it alone, take the antibiotics or, maybe, take natural antibiotics, such as garlic?

We are worried that if the antibiotics do not completely kill all the bacteria, the remaining bacteria could evolve into a drug-resistant strain. We are also concerned that the antibiotic may kill the "good" bacteria in her stomach, leading to other complications, such as irritable bowel syndrome and diarrhoea.

A: Helicobacter pylori is a gram-negative bacterium found in the stomach.

The serological prevalence of helicobacter pylori infection in people without any symptoms in Asian countries ranges from 13.7 per cent to 91.7 per cent.

In Singapore, the prevalence is 31.4 per cent. It is more common among the Chinese and Indians.

A helicobacter pylori infection results in a wide spectrum of diseases that involve the stomach and the duodenum of the small intestine.

They include acute and chronic active gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma and gastric malignancy. It is the most consistent risk factor for gastric cancer.

It is well known that the indiscriminate use of antibiotics increases the problem of antibiotic-resistant bacteria. But it does not lead to irritable bowel syndrome. Similarly, antibiotic resistance can occur with the helicobacter pylori bacteria as well.

Nonetheless, I would advise my patients who are found to have the infection to have it eradicated.

Current scientific data shows that helicobacter pylori infection is the most common proven risk factor for gastric cancer. Its elimination is, therefore, the most promising strategy to reduce the incidence of gastric cancer.

In fact, failing to eradicate the helicobacter pylori infection, along with the indiscriminate use of antibiotics, will create a more resistant strain of the bacteria.

As such, it is advisable to confirm that the bacteria has been eradicated with a urea breath test after the antibiotic therapy is completed.

Whether or not your wife should leave the infection alone, take the prescribed antibiotic or consume garlic is best discussed with your attending physician who can devise a management plan that is tailored to her individual needs.

DR ONG WAI CHOUNG, Senior consultant at the department of gastroenterology and hepatology at Singapore General Hospital

This article was first published on June 11, 2015.
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