Amiodarone is a life saving anti arrhythmic drug,but it has a complex side effect profile involving organs that include thyroid,lungs, liver and eyes. It is well known that patients on long term amiodarone therapy should be followed up in a structured manner including regular thyroid function tests,liver function tests,chest xray and eye examination.There are guidelines suggested by the Summary of Product Characteristics (SPC) for amiodarone and the British National Formulary.
To audit the performance of follow up investigations for patients on long term amiodarone and to assess the incidence of toxic side effects .
134 patients who received amiodarone over a period of 12 months in 2002 were audited. Majority were more than 70 years old(80%). Most common indication was atrial fibrillation(71%). 67% had thyroid functions checked before starting therapy which was repeated in 32% at 6 months ,31% at 12 months and 26% at 18 months. Only 3% had FT3 checked though it is an important part of thyroid function test in patients on amiodarone.8 (6%)patients developed thyrotoxicosis and 14(10%) had hypothyroidism. Out of 37 patients who had pre existing lung disease only 2 had pulmonary function tests.Chest x ray was performed in 131(97%)patients which showed lung parenchymal abnormalities in 28(21%).Two persons had CT chest and both were diagnosed as amiodarone lung. Liver function tests were done in 132(98% ) patients which was abnormal in 62(46%).28 of these patients were found to have developed liver function abnormalities after initiation of amiodarone.
Large proportion of patients did not have thyroid functions adequately checked.The incidence of complications like thyrotoxicosis was significantly high.Arrangements for regular follow up tests may prevent these serious side effects.
22 - 24 Mar 2004
British Endocrine Societies