Anita Graves · Prevention of Future Deaths report

On 27th January 2023, an investigation was commenced into the death of Anita Graves, aged 92 years. The investigation concluded at the end of the inquest on 30th May 2023.
The outcome of the inquest was that the medical cause of the death of Mrs Graves was:
1a. Urinary Tract Infection
1b. E.Coli
2 Hyperthyroidism

The conclusion was that she died from E.Coli infection following treatment for hyperthyroidism.

Mrs Graves was diagnosed with hyperthyroidism in 2019. Her condition was monitored by specialists from the Endocrinology Team at the local hospital and regulated by carbimazole and propranolol. The regular dose of carbimazole in particular, was adjusted periodically by Mrs Graves’ GP in light of regular reviews of blood test results under the supervision and guidance of the Endocrinology Team.
An unusually abnormal blood test result in early December 2022 revealed that Mrs Graves’ thyroid had rapidly and unexpected become underactive. The clinical decision was taken to discontinue temporarily the carbimazole and propranolol medication pending analysis of repeat blood tests which were scheduled for early January 2023.
By 22nd December 2022, Mrs Graves’ thyroid had become overactive again and resulted in an emergency admission to hospital for treatment. Carbimazole and propranolol were re-started and by 30th December 2022, the FT4 had dropped from 116.6 to 64.8, reflecting a significant improvement in thyroid hormones.
Mrs Graves remained in hospital, suffering a persistently high heart rate during her admission and developed an E.Coli urinary tract infection, which did not respond to treatment and brought about her death on 4th January 2023.
The evidence at the inquest revealed that carbimazole is dispensed in 5mg, 10mg and 20mg tablet forms, which are visually virtually impossible to distinguish from each other. The adjusted doses periodically required different daily combinations of these tablets to achieve the correct prescribed dose. Compounding the potential confusion of differing strengths of tablets was their visual similarity to aspirin, which was also part of Mrs Graves regular prescription and the variety of packaging (unmarked pharmacy boxes and different manufacturer’s packaging, for example) in which the carbimazole tablets were dispensed by the community pharmacy.
The inquest found that Mrs Graves had inadvertently taken more than the prescribed dose of carbimazole which had caused the sudden underactive thyroid in early December 2022.
The ongoing potential confusion of the differing strengths of carbimazole tablets was highlighted by both the specialist Endocrinology Team pharmacist and consultant during the evidence notwithstanding that this issue had been recognised and the subject of national guidance historically.
Whilst Mrs Graves’ hyperthyroidism was not the direct cause of her death, it was a significant contributory condition and the inadvertent increased dose of carbimazole had been the precipitating factor in her hospitalisation and was the background to her inability to fight the infection from which she died.

(1) That the visual similarity of tablets of differing strengths of carbimazole to each other and to aspirin presents a risk of inadvertent overdose; and
(2) That the dispensing process in the community for carbimazole appears to contribute to rather than mitigating the risk