Voltaren and other forms of diclofenac carry a risk of cardiovascular events including heart attacks and strokes, Medsafe has warned.
Medsafe - the Ministry of Health's medicines safety authority - said diclofenac was a non-steroidal anti-inflammatory drug used for the relief of moderate pain and inflammation.
Recent publications had suggested an increased risk of cardiovascular events such as heart attack and stroke with the use of the drug, Medsafe said.
Non-steroidal anti-inflammatory drugs - including diclofenac - were safe and effective at relieving pain and inflammation for most people.
However, smokers, those with high blood pressure, high cholesterol, diabetes, or poorly functioning kidneys should check with their healthcare professional that the medicine was appropriate, Medsafe said.