A study at the Harvard Medical School revealed that one out of three persons covered under Medicare consulted more than one doctor for painkillers, a practice that could prove risky to the patients.
The researchers said taking painkillers from several doctors increases the chance of injury and can cause several other diseases.
The study culled out details of 1.8 million seniors under Medicare and who receive drugs called opioids. Opioids are various types of painkillers such as hydrocodone and oxycodone.
Study author Anupam Jena, who is an assistant professor at Harvard Medical School and a physician at Massachusetts General Hospital said, "The results were shocking as I thought it would be 5 to 10 per cent. But when we ran the numbers, it turned out to be 30 per cent."
Researchers said patients with multiple doctors had two times more chances of being hospitalised for complications related to medicine.
When opioids are taken above the prescribed limit, some of the problems include severe constipation, confusion or disorientation, breathing problems or severe overdosing leading to death.
Those under opioids medication have been advised not to drive during medication. Scientists said many doctors were not even aware of the fact that their patients were consulting other doctors as well.
Science World Report states that over the last 20 years, the use of opioids has gone up and researchers said the reason could be increase in its usage due to consulting multiple doctors.