A 36 year old lady referred to the endocrinology clinic, with a history of tiredness, fatigability and abnormal thyroid function. She had no significant past medial history, no family history of thyroid disease and her only medication was an oral contraceptive pill (Ovranette). She had experienced fatigue over a period of 5 years, since returning from a visit to Pakistan, during which she had developed diarrhoea which had persisted for about 12 months. Thyroid function tests at the time showed TSH 4.3 mlU/l with normal FT4, thyroid peroxidase antibodies were elevated at 110 IU/l. 18 months later she became symptomatically better and her thyroid function normalised. She continued to have annual thyroid function tests and after five years her thyroid function tests became abnormal with TSH ranging from 6 to 9 m IU/l. Initially she only complained of slight tiredness, but 7 months later, she became unwell, with tiredness, palpitations, nervousness, flushing and diarrhoea. Examination revealed cool hands, dry skin, and slow-relaxing reflexes; a small goitre; pulse was 64 regular with normal blood pressure. Thyroid function tests showed TSH 4.93 mIU/l, normal free T4 and TPO 41 IU/l. She was commenced on thyroxine 100 mcg OD. On further follow up she had variable symptoms of tiredness and episodes of palpitations and flushing, whilst serum TSH fluctuated between 1.9 and 6.0 MIU/l. She was compliant with her medication, celiac screen was negative, and she was not taking any drugs or herbal remedies interfering with thyroxine absorption. She was therefore advised to crush her thyroxine tablets. On subsequent clinic visits she was feeling very well with no further fluctuations in her thyroid function. We postulate that compliant patients with a variable response to thyroxine and no evidence of malabsorption, or concomitant intake of interfering drugs or herbal remedies, merit a trial of pulverised thyroxine.
06 - 07 Nov 2006
Society for Endocrinology