title: Incidence and pattern of thyroid dysfunction in patients on chronic amiodarone therapy: experience at a tertiary care centre in oman.
abstract: OBJECTIVE
  To determine the incidence and pattern of thyroid dysfunction (TD) in patients on chronic amiodarone therapy.
  
  
  METHODS
  A retrospective study which evaluated 59 patients who had received amiodarone therapy regularly for at least 12 months from a period of 3 years from October 2007 to October 2010. The patients were followed-up at the cardiac clinic at Sultan Qaboos University Hospital, Muscat, Oman.
  
  
  RESULTS
  The mean age of the cohort was 63 ± 13 years ranging from 27 to 98 years. Fifty-one percent (n = 30) of the patients were female. There were 11 (19%) cases of thyroid dysfunction (TD). Seven (12%) patients were hypothyroid, 3 (5%) had hyperthyroidism and 1 (2%) patient had sub-clinical hypothyroidism; no cases of sub-clinical hyperthyroidism were noted. Female gender and presence of anti-thyroid peroxidase antibodies were significantly associated with amiodarone-induced hypothyroidism (p = 0.001) while age, amiodarone dose and duration of therapy were not correlated with the development of TD (all p-values > 0.05).
  
  
  CONCLUSIONS
  Amiodarone-induced thyroid dysfunction is prevalent. Hypothyroidism was more frequent and seen more in female patients and those who had positive anti-thyroid peroxidase antibodies. Initial screening and periodic monitoring of thyroid function is mandatory for all patients on amiodarone therapy.
authors.affiliation: Department of Medicine, Sultan Qaboos University Hospital, Oman.
authors.forename: H
authors.initials: H
authors.lastname: Farhan
authors.affiliation: Department of Medicine, Sultan Qaboos University Hospital, Oman.
authors.forename: A
authors.initials: A
authors.lastname: Albulushi
authors.affiliation: Department of Pharmacy, Sultan Qaboos University Hospital, Oman.
authors.forename: A
authors.initials: A
authors.lastname: Taqi
authors.affiliation: Department of Medicine, Sultan Qaboos University Hospital, Oman.
authors.forename: A
authors.initials: A
authors.lastname: Al-Hashim
authors.affiliation: Department of Medicine, Sultan Qaboos University Hospital, Oman.
authors.forename: K
authors.initials: K
authors.lastname: Al-Saidi
authors.affiliation: Department of Clinical Biochemistry, Sultan Qaboos University Hospital, Oman.
authors.forename: K
authors.initials: K
authors.lastname: Al-Rasadi
authors.affiliation: Department of Medicine, Sultan Qaboos University Hospital, Oman.
authors.forename: A
authors.initials: A
authors.lastname: Al-Mazroui
authors.affiliation: Department of Pharmacology & Clinical Pharmacy, College of Medicine & Health Sciences, Sultan Qaboos University, Muscat, Oman ; Gulf Health Research, Muscat, Oman.
authors.forename: I
authors.initials: I
authors.lastname: Al-Zakwani
keywords: Oman; Thyroid diseases; amiodarone; hyperthyroidism; hypothyroidism; thyrotoxicosis