Those taking a widely prescribed medication are being urged to "call 111" if they experience a particular symptom in the chest. This could indicate a "rare but serious" side effect of the drug. Sertraline is an antidepressant commonly used to treat depression and a range of other mental health conditions. While no specific figures for the drug are available, it is known to be taken by a significant proportion of the more than eight million people in England currently on antidepressants. The