Why does Voltarol interact with my daily aspirin?
Q) I've recently been told by my doctor that I can no longer take Voltarol for pain relief, as it will interact with the daily aspirin I've been prescribed for prevention of heart trouble. I've always found Voltarol very effective. What can I do now and is this a common problem for people with heart problems and arthritis?
Mrs Cora Mayhew, Bristol (Summer 2006)
A) Many older people take low-dose aspirin to reduce the likelihood of their having a thrombosis (a blood clot in an artery or vein which can lead to a heart attack or stroke), but also take a non-steroidal anti-inflammatory drug (NSAID) for their arthritis. There are two important points about aspirin and NSAIDs. Firstly, they have some similarities in the way they work because they target the same biochemical pathways. However, the effects of an aspirin last much longer than that of an NSAID, which is only effective for a few hours. Taking an NSAID may block the important action of aspirin but not the other way round so, if you're taking both aspirin and an NSAID, take the aspirin about an hour before the NSAID. Secondly, why, you might ask, take aspirin and an NSAID if they work the same way? Well there are subtle differences and aspirin works much better at preventing thromboses, so sometimes it's necessary to take both. Of course, some of the newer NSAIDs, the so-called coxibs or COX-2 inhibitors, may even have a slight tendency to promote thromboses so taking aspirin along with them is even more important. The problem is that any reduction in stomach ulcers and indigestion which occurs with the newer NSAIDs is lost when aspirin is taken as well. This then results in the prescription of a drug to protect the stomach. There are several types of these available (see Arthritis Today Summer 2005, 'Pain Relief After Cox-2s'). This is an area of change. Drugs have been withdrawn and recommendations changed. Because of the tendency of some NSAIDs to promote thrombosis, some doctors are now very reluctant to prescribe them at all. My view is that the pendulum has swung too far against COX-2s – they're very effective in reducing arthritis pain and we shouldn't be depriving everyone of them just because there's a slight (but definite) increase in risk of ‘cardiovascular events’ such as heart attack or stroke when taking these drugs. After all, there are risks and benefits with taking any drug and decisions have to be made on an individual basis.