Experience in the use of radioactive iodine therapy for hyperthyroidism in Nigerian patients. A study of twenty-two patients.

This is a descriptive and follow-up study of the efficacy of radioiodine (131I) in the treatment of hyperthyroidism in Nigerian patients, and is aimed at creating awareness about the therapy amongst medical practitioners in the West African sub-region. Twenty-two patients (13 female, 9 males) were seen with clinical and biochemical features of thyrotoxicosis, and were treated with 131I between 1991 and 1999. The age range was 31 to 60 years, with a mean age of 44.2 +/- 1.8 years. The indications for 131I therapy were diverse and included its use as a first-line treatment for Graves' disease, thyrotoxic heart disease, recurrent thyrotoxicosis and failed antithyroid drug therapy. An incremental fixed-dose regimen was used in successive years, for different batches of patients. The duration of follow-up ranged from two months to nine years with a mean duration of 3.6 +/- 0.5 years. Three patients achieved euthyroidism, two patients needed a re-treatment with 131I because of persistent Hyperthyroidism. Nine patients developed hypothyroidism between two to 30 months of receiving 131I therapy. While seven other patients defaulted soon after the treatment and one patient who also had type 1 diabetes mellitus suffered a sudden death after two months. In conclusion, our experience revealed similar outcomes as have been reported by other workers. Radioactive iodine was found to be a safe and an effective treatment for hyperthyroidism in Nigerian patients, but a high rate of default precludes adequate long-term follow-up.