Preventing the co-prescription of tamoxifen and fluoxetine in General Practice.

In 2010 a population-based cohort study showed that there was decreased efficacy of the breast cancer drug tamoxifen when used in combination with fluoxetine, a commonly used SSRI antidepressant. The aim of this project was to identify patients who may be affected by this co-prescription and suggest a change in medication. The project was conducted across two GP practices in Clevedon (The Riverside Practice & The Green Practice), Bristol. The patients were all from the active patients register at each surgery. A search was conducted to find all those on tamoxifen and fluoxetine, using the EMIS computer system. These patients would then be sent a letter to attend clinic. The new data would then be discussed with them before recommending a change of antidepressant (typically to sertraline). Three patients were found to be on both medications. They were all called into clinic and changed from fluoxetine to sertraline. Furthermore a presentation was given to all GPs at the two surgeries alerting them to the new guidelines. A message was also set up to flash on the computer system whenever an attempt was made to co-prescribe the two drugs. All the patients on tamoxifen in these two practices are now receiving the optimum treatment. Furthermore interventions have been put in place to ensure that this remains the case in future. Another data collection should be conducted in one year. This project provides a good example of how this problem could be resolved at other GP surgeries.