Endocrine Abstracts

Background: Graves’ disease is a common cause of thyrotoxicosis,especially amongst females. In the UK,initial treatment is usually with anti-thyroid drugs, using either a ‘block and replace’ or a titrating regime. A meta-analysis suggests about 50% chance of relapse after the initial course of treatment and may then require definitive cure with radioactive iodine or surgery.

Method: A retrospective audit of patients with Graves’ disease attending our endocrine clinics from 2016–2018 was conducted, to study our medical management of this condition and the rate of relapse. The European Thyroid Association Guideline for the management of Graves’ Hyperthyroidism was used as the standard.

Results: A random selection of 36 patients with Graves’ disease was audited. About 70% were female, and the age ranged 27–73 years. Almost three quarters of the audited patients had completed treatment, while the rest were still on treatment and 1 patient was lost to follow-up. Mean duration of treatment was 17 months. All but one patient had thyroid antibodies checked early during treatment, and these were elevated, however only 13 patients had them rechecked prior to stopping treatment. The titrating regime was used in 64% and the ‘block and replace’ regime in 36%, however a few patients were switched between the two regimes during treatment. About 38% (n= 10/26) of patients had relapsed and of these, half did not have antibodies retested prior to withdrawal of treatment. Where they were rechecked, the mean TSH receptor antibody was 9.41 IU/l (normal range <1.22 IU/l) prior to stopping treatment. Four of the ten patients that relapsed had been on a ‘block-and-replace’ regime while six had been on a titrating regime. Definitive treatment (radioactive iodine or surgery) was offered to 16 patients due to relapse or difficulty in stopping treatment.

Conclusions: Our relapse rates appear to be lower than in other studies, possibly because the period of follow-up was limited to the audit period. The titrating regime appears more popular amongst the six Consultants but there was no convincing evidence of superiority of either a titrating or ‘block and replace’ regime in preventing relapse. Many patients did not have their thyroid antibodies retested prior to withdrawing anti-thyroid medications. The importance of doing this and using it as a guide when considering withdrawal of treatment will be publicised within the team. A further audit will be performed in due course to see whether this has been successfully implemented and has influenced the rate of relapse.