Metoprolol, a commonly prescribed beta blocker that costs only 18 cents per pill, can save lives when it’s administered to heart attack victims on the way to the hospital.

Spanish researchers conducted a trial on 270 patients who were transported by ambulances to seven hospitals in Spain.

The patients were assigned to receive either intravenous metoprolol or a placebo (inactive) treatment as soon as they were diagnosed as having a heart attack.

During the week following their heart attack, the patients were given a magnetic resonance imaging (MRI) test, designed to measure how much damage the heart attack had caused.

The researchers found that the patients who took metoprolol suffered milder heart attacks than those who had received the placebo, and this correlated with their heart’s ability to function better.

The study, which was a collaboration between Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) in Spain and the Icahn School of Medicine at Mount Sinai in New York, was published in the journal Circulation.

The researchers are planning to extend the clinical trial with a much larger international trial. The hope is that administering the drug in this way will lower the death rate as well.

If these results are replicated, the study will demonstrate that there is a new and impressive health benefit linked to one of the oldest and least expensive cardiac drugs around.