Recent research has linked pain killers like aspirin, acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) to hearing loss. New findings suggests people on such drugs are also tripling their risk of kidney cancer, say scientists.
A study of over 125,000 participants found those who regularly took over the counter anti-inflammatories were 51 per cent more likely to develop the disease.
But the researchers found those who used them for over a decade, such as arthritis sufferers, were almost three times more likely to suffer renal cell cancer (RCC), the most common form of kidney cancer.
Aspirin was the only member among the group of medications - known as NSAIDS (non-steroidal anti-inflammatory drugs) - that was found to be safe.
Dr Eunyoung Cho, of Harvard Medical School, Boston, and colleagues said: 'In these large prospective studies of women and men, we found that use of non-aspirin NSAIDs was associated with an elevated risk of renal cell cancer, especially among those who took them for a long duration.'
Renal cancer accounts for two per cent of all cancers diagnosed in the UK. It is difficult to treat with around one in three surviving the disease.
Pain-relieving medications - or analgesics - are among the most commonly used groups of drugs and some appear to have protective effects against cancer.
But writing in Archives of Internal medicine the researchers said: 'However some epidemiologic data, mainly from case-control studies, suggest an association between analgesic use and an increased risk of RCC.'
So Dr Cho and colleagues analysed data on 77,525 women and 49,403 men whose use of aspirin and other NSAIDs was recorded for up to twenty years during which time 333 developed renal cell cancer.
A 19 per cent decrease in risk of developing the disease was identified for use of non-aspirin NSAIDs for less than four years.
But the danger rose by 36 per cent for use for between four and ten years and nearly three times for use for ten or more years.
In carrying out the study the researchers also took into account other risk factors for RCC such as body weight, smoking, recreational physical activity and history of high blood pressure.
NSAIDs are also taken by sufferers of bowel conditions such as Crohn's Disease, and as a preventive measure against Alzheimer's Disease.
The researchers said: 'Risks and benefits should be considered in deciding whether to use analgesics; if our findings are confirmed, an increased risk of RCC should also be considered.'
The overall risk of renal cell cancer remains small in comparison to that of other major diseases.
Only six per 100,000 people are expected to develop the condition compared to 95 per 100,000 for Alzheimer's.