Complex sentence: Chemically, dronedarone is a benzofuran derivative related to amiodarone, a popular antiarrhythmic the use of which is limited by toxicity due its high iodine content (pulmonary fibrosis, thyroid disease) as well as by liver disease.
Split into simpler sentences: Chemically, dronedarone is a benzofuran derivative related to amiodarone, a popular antiarrhythmic. The use of amiodarone is limited by toxicity due its high iodine content (pulmonary fibrosis, thyroid disease) as well as by liver disease.