TORONTO -- A new study confirms that statin drugs and some antibiotics can interact badly.

The study finds that while the interactions are rare, they can be serious. And the authors say that given that these drugs are commonly prescribed and commonly prescribed together, the combination should be avoided.

The study was done by scientists at Western University in London, Ont., and the Institute of Clinical Evaluative Sciences in Toronto. It suggests that for every 100 patients who receive the combination of the drugs, there will be one additional hospitalization for acute kidney failure.

Lead author Dr. Amit Garg says doctors should consider prescribing other antibiotics, not clarithromycin or erythromycin, for patients who are on statins but need an antibiotic.

"Most people will not experience statin toxicity when they take these antibiotics," says Garg, who is a nephrologist (kidney specialist) at the Lawson Health Research Institute in London.

"But a small proportion will. And that small proportion that do are getting very serious side-effects, where they're hospitalized, they have acute kidney injury, some of them require acute dialysis.

"So we just want to raise attention to the point that this is a preventable drug interaction. There are very simple things that can be done to prevent this from happening."

The study suggests that "many deaths and hundreds of hospital admissions with acute kidney injury" in Ontario may have been attributable to people on statins being prescribed these antibiotics.

Garg says doctors prescribing antibiotics to people on statins could consider using another drug. For instance, the increased risk was not seen with the antibiotic azithromycin, which is in the same family -- the macrolides -- as the two drugs that can trigger the interaction.

As well, he says, doctors could consider suggesting patients take a break from their statin drugs if they need to go on antibiotics to clear up an infection.

But he says the authors do not want to convey the message that people should not take statin drugs. The cholesterol-lowering drugs are important, he insists.

Dr. Mahyar Etminan, a scientist with the therapeutic evaluation unit of the Provincial Health Services Authority for Vancouver, agrees with the message of the study.

Etminan, who was not involved in the study, says the work was well done and while it found that the rate of serious adverse reactions was low, these are risks that can be avoided.

"Since there is a safer alternative, azithromycin, clinicians may opt to prescribe azithromycin in patients who require a macrolide antibiotic ... and are on a statin," says Etminan, who is also with the faculty of medicine at the University of British Columbia.