But the companies making the drugs argue that only a small percentage of people using the drugs abuse them and there have been no sign of unfavorable results when the drugs were used as recommended.
Reports in the British Medical Journal said patients were reporting substance abuse problems with OTC drugs containing codeine phosphate.
Alone, codeine phosphate can only be obtained with a prescription. But when mixed with other drugs like ibuprofen, the drug becomes available to all. The journal reported that some patients were quadrupling the recommended doses.
The Over Count website showed more than 4,000 people with an addiction to Solpadeine - a combination of paracetamol and codeine. Doctors say this is one of the most common OTC drugs to which patients become addicted.
Dr. Chris Ford told the BBC that these numbers, he fears, are only the tip of the iceberg. However, the drug should not be banned but rather more information should be available on the packaging, he said.
He said, "Thousands and thousands of people take these drugs and don't have any problems. It's a very small minority who do. But our anxiety is that it's a problem which is not being picked up by the public or doctors, and that we're just seeing the tip of the iceberg."
A GlaxoSmithKline spokesperson said the company, who make Solpadeine, are taking these reports seriously but added that instances of OTC medicine misuse are rare.
He added, "Hundreds of thousands of people benefit from safe and effective use of Solpadeine every year. There are clear instructions for use on our labels, and if these are followed there is no evidence that the product will cause dependency."
