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Prescription and other medicines: not always a good combinationPrescription and other medicines: not always a good combination
When taking over-the-counter medicines, most of us don't tend to think about the possibility of them interacting with our prescription medicines, but we should.
Over-the-counter medicines contain active ingredients that make the medicine work as intended. These active ingredients can interact with the active ingredients of any other medicine — be it a vitamin or a herbal, natural, over-the-counter or prescription medicine.
The more medicines you take, the greater the risk of interactions. Older people are also more at risk, because their bodies tend not to handle medicines as well as younger people.
Examples of interactions
St John's wort can interact with some antidepressant medicines to cause a potentially dangerous reaction.
Taking aspirin at the same time as another blood-thinning medicine such as warfarin can result in an increased risk of unwanted bleeding.
Taking an antacid such as Mylanta, Gaviscon or Quick-Eze at the same time as some antibiotics can reduce the absorption of the antibiotic into the body. This can result in the antibiotic being less effective in fighting the infection for which it was intended.
Some anti-inflammatory medicines available over the counter, such as ibuprofen (eg Nurofen) and naproxen (eg Naprogesic), can interact with blood-pressure tablets to make them less effective, which may result in a rise in blood pressure.
Avoiding interactions
Whenever your doctor or pharmacist recommends or sells you a new medicine, tell them about all the other medicines you are taking, including any over-the-counter, natural and herbal medicines. Keeping a list of all your medicines and carrying it around with you will make this task easier, because you can refer to it or give it to them.
When you buy over-the-counter medicines, read the label. It will tell you about the main medicine combinations to avoid. Similarly, for prescription medicines, check the Consumer Medicine Information leaflet. Or, check with a doctor or pharmacist.
Over-the-counter medicines are medicines that you can buy without a prescription at pharmacies, supermarkets, convenience stores, etc.
MedicinesTalk is a free quarterly newsletter for consumers written by consumers about using medicines wisely. Subscribe to the hard copy version using our online ordering system, or write to MedicinesTalk, National Prescribing Service Limited, PO Box 1147, Strawberry Hills, NSW 2012.
Date published: 2008-03-01 00:00:00
Reasonable care is taken to provide accurate information at the date of creation. This information is not intended as a substitute for medical advice from a qualified health professional. Health professionals should rely on their own expertise and enquiries when providing medical advice or treatment. Where permitted by law, NPS disclaims all liability (including for negligence) for any loss, damage or injury resulting from reliance on or use of this information. Read our full disclaimer.
References to brands should not be taken as an endorsement by NPS.
