The most common side effects with Fosavance (seen in between 1 and 10 patients in 100) are headache, musculoskeletal (bone, muscle or joint) pain and gastro-intestinal symptoms such as abdominal (tummy) pain, dyspepsia (indigestion), constipation, diarrhoea, flatulence (wind), oesophageal (gullet) ulcers, dysphagia (difficulty swallowing), abdominal distension (swollen tummy) and acid regurgitation.