21:00Inside HealthBreast cancer and Tamoxifen; Drug holidays; Medicines for children; Cardiac training rangeBBC Radio 4 Duration: 28 minutes Tue 23rd Apr 2013, 21:00 on BBC Radio 4 LWAvailable for over a yearListen nowDr Mark Porter goes on a weekly quest to demystify the health issues that perplex us.GenresFactualHealth & WellbeingBrandInside Health Source: BBC Online