Inter-regional differences in dysthyroidism due to amiodarone: comparison of spontaneous notifications in Aquitaine, Midi-Pyrenees and Languedoc-Roussillon
Bagheri, H.; Lapeyre-Mestre, M.; Levy, C.; Haramburu, F.; Hillaire-Buys, D.; Blayac, J.P.; Montastruc, J.L.
Therapie 56(3): 301-306
2001
ISSN/ISBN: 0040-5957 PMID: 11475812 Document Number: 534225
Amiodarone hydrochloride is used in the treatment of ventricular and supraventricular arrhythmias. Because of its iodinated structure, thyroid dysfunction can occur during amiodarone therapy. The reported overall incidence is variable (2-24 per cent) and depends on several factors (past thyroid history, daily iodine intake,...). The present retrospective (1990-97) study was performed using the French pharmacovigilance database in order to compare the frequency of hypo- and hyperthyroidism in three areas in the South of France: Midi-Pyrénées, Aquitaine and Languedoc-Roussillon. For each case, the following data were recorded: age, sex, dysthyroidism history, dosage, duration and indication of amiodarone and delay to onset of dysthyroidism. We collected respectively 37, 50 and 9 cases of hypothyroidism in Midi-Pyrénées, Aquitaine and Languedoc-Roussillon and 20, 69 and 11 cases of hyperthyroidism respectively in the same areas. These data show the predominance of reported amiodarone-induced hyperthyroidism in Aquitaine and Languedoc-Roussillon. Hypothyroidism seems more frequent in Midi-Pyrénées, a non-maritime area. The sex ratio (male/female) was significantly different for the occurrence of hypothyroidism in Midi-Pyrénées (1.8 versus 0.5 in Aquitaine and 0.8 in Languedoc-Roussillon). The delay to onset of hypothyroidism was significantly shorter in Midi-Pyrénées (17.1 months +/- 24.5) when compared with Aquitaine (28.7 +/- 28.1) or Languedoc-Roussillon (43.4 +/- 45). Our results show an interregional difference in the occurrence of hypo/hyperthyroidism due to amiodarone.