New Delhi, Nov. 23: A set of drugs commonly prescribed to counter stomach acidity and heartburn should be used at the lowest effective dose possible and the shortest length of time, a research review has said raising concerns about potentially serious side-effects.

Drugs called proton-pump inhibitors reduce gastric acid secretion and are effective in allaying gastric distress -– sensations of pain or burning in the stomach or the oesophagus -– caused by stomach acids.

These drugs are prescribed worldwide, including India, where spicy cuisine can exacerbate gastric acidity.

"Proton-pump inhibitors are associated with a number of rare but potentially serious adverse effects. These uncommon effects become highly relevant when considering tens of millions of people who take (these drugs) worldwide," said the research review published today in the Canadian Medical Association Journal.

The review, led by Todd Lee, an internal medicine specialist at McGill University in Montreal, has said proton-pump inhibitors are the most widely prescribed gastrointestinal drugs. About 15 million patients were prescribed these drugs in the US alone during 2013.

The researchers, who analysed numerous studies on the proton-pump inhibitors, have outlined their potential risks, including rebound heartburn after discontinuing the drugs, malabsorption of essential nutrients such as vitamin B12, iron and magnesium, and an increased risk of intestinal infections with certain bacteria, including Clostridium difficile, which can cause intractable diarrhoea.

The review has also cautioned about an increased risk of fracture in patients prescribed long-term therapy with proton-pump inhibitors.

"The concerns about the overuse of proton-pump inhibitors isn't new to India," said Chandra Gulhati, a pharmacologist and editor of the Monthly Index of Medical Specialities, India, a journal of drugs, who was not associated with the review by the Canadian researchers.

Among the proton-pump inhibitors sold in India are omeprazole, pantoprazole, esomeprazole and rabeprazole.

Some of the common brand names of these drugs in India are Omez (omeprazole), Pan and Pantocid (pantoprazole), Esoz and Nexium (esomeprazole) and Prorab and Rablet (rabeprazole).

"Studies suggest that two in three people consuming proton-pump inhibitors do not suffer the disorders for which these drugs are indicated," Gulhati said.

He said these drugs are often used for prolonged periods. "Using them for a month or longer can lead to rebound acid hyper-secretion with the result that patients start taking the drugs again, creating long-term dependence."

MIMS India regularly publishes alerts against the overuse of proton-pump inhibitors.

Some doctors in Calcutta said they were recommending antacids such as Rantac (ranitidine) and Famtac (famotidine) to their patients.

"Rantac or Famtac close one of the avenues of production of acids from the cells, but they do not stop acid production completely as proton-pump inhibitors do. So the proton pump inhibitors often work better, but they are harmful in the long run," surgical gastro-enterologist Sanjay De Bakshi said.

The review has recommended lifestyle modifications such as limiting the consumption of caffeine and alcohol, which can exacerbate gastric distress, and greater efforts by doctors to prescribe these drugs only when necessary and supported by medical evidence.

Doctors have been asked to frequently reassess the need to prescribe these drugs to their patients.

The researchers have said that non-medication interventions should be attempted with patients who have symptoms of gastro-oesophageal reflux disease. These include avoiding large meals before sleeping and reducing the consumption of caffeine and alcohol.