A Danish study has called for the popular anti-inflammatory drug Voltaren to be sold only with a prescription, claiming the drug increases the likelihood of users suffering strokes.

The findings were presented to the European Society of Cardiology 2010 Congress in Stockholm, Sweden by Dr Gunnar Gislason last month.

The study claims that using diclofenac, marketed in New Zealand as Voltaren, increases the chance of those not thought to be at risk of suffering strokes by 86 per cent.

It also said there's a higher risk of stroke for those taking high doses of ibuprofen, which is in the painkiller Nurofen.

The eight-year study, which involved more than 2.5 million healthy Danes, said care needed to be taken when patients were using non-steroidal anti-inflammatory drugs, in particular rofecoxib and diclofenac.

The study recommended the over-the-counter sale of these drugs should be reassessed.

Neurologist and stroke expert Professor Valery Feigin told 3 News the painkillers should be banned.

"I would think these studies [would be] the last nail in the coffin for these types of medication," he said.

"I seriously would not recommend this medication to anyone."

A spokesman for Novartis, which makes Voltaren, sent out a statement which said the company was aware of the study but did not believe "it changes the benefit to risk assessment for diclofenac when used as directed".

"Diclofenac should be used at the lowest possible dose for the shortest duration of time, in keeping with advice provided to prescribers in the approved product information," said the statement.

"Novartis maintains a robust drug safety monitoring process for all its medicines, the data from which is shared with regulatory authorities on a regular basis. Novartis will continue to work with regulatory authorities to monitor and analyse research related to our medicines to ensure the information provided to both doctors and patients is consistent with current scientific knowledge."

Ministry of Health senior adviser Susan Kenyon told Radio New Zealand the risk was already well-known, and Medsafe currently recommends that patients use the lowest effective dose of the drugs for the shortest possible time.

Dr Kenyon said Ministry data showed heart attacks, rather than strokes, were a more likely complication from diclofenac and ibuprofen use.

- with NZ Herald staff