Question
Radioactive Iodine
Q73 marksShort Notes
Answer
Radioactive iodine (I-131) is used in the treatment of hyperthyroidism and thyroid carcinoma.
Mechanism of action
- Selectively taken up by the thyroid gland (via the sodium-iodide symporter)
- Emits beta radiation, which destroys thyroid follicular cells locally with minimal effect on surrounding tissue
Uses
- Hyperthyroidism (Graves’ disease, toxic nodular goitre)
- Differentiated thyroid carcinoma (ablation of residual/metastatic tissue after surgery)
Advantages
- Non-invasive, often curative in a single dose, avoids surgical risks
Disadvantages/adverse effects
- Delayed onset (weeks to months)
- Hypothyroidism (common long-term consequence, requires lifelong replacement)
- Contraindicated in pregnancy/breastfeeding
- Radiation precautions required after administration
- 1Thyroid Hormones and Antithyroid Drugs
Other Years Asked
- 1T4 and very low TSH
levels. A diagnosis of hyperthyroidism was made.
(2022 July (Supplementary) (2019 Scheme)Essay · 10 marks
- 2Compare Radioactive Iodine and Carbimazole.2024 March (Supplementary) (2019 Scheme)Short Essay · 8 marks
- 3Classify Thyroid inhibitor drugs. Describe the mechanism of action, and adverse
effects of carbimazole. Explain the role of iodides in hyperthyroidism. (2+2+2)2022 May (Supplementary) (2010 Scheme)Essay · 6 marks
- 4(2023 July (Supplementary) (2019 Scheme)Essay · 6 marks
- 5A 32years old woman, presented with complaints of weight loss, palpitations,
sweating, irregular menses and occasional tremors of hands since 2-3 months.
Clinical examination revealed a diffusely enlarged thyroid gland and blood tests
showed decreased TSH. She was started on medication for Grave’s disease.2025 March (Supplementary) (2010 Scheme)Essay · 6 marks
- 6Classify antithyroid drugs. Write the advantages and disadvantages of using
radioactive Iodine. (2+2+2)2021 February (Supplementary) (2010 Scheme)Essay · 6 marks
- 7A 35 years old woman came with complaints of heat intolerance, retraction of upper eyelid
and menstrual irregularities. Her T3 , T4 , FT4 & FT3 are elevated while TSH is suppressed.
Answer the following:2015 February (2010 Scheme)Essay · 6 marks
- 8Treatment of thyrotoxic crisis.2023 January (Supplementary) (2019 Scheme)Short Answer · 4 marks
- 9Pharmacotherapy of Thyrotoxic crisis (thyroid storm)2024 June (Supplementary) (2019 Scheme)Short Answer · 4 marks
- 10Mechanism of action, uses and adverse effects of Radio active iodine.2025 March (Supplementary (SAY)) (2019 Scheme)Short Answer · 4 marks
- 11Carbimazole2022 October (Supplementary) (2010 Scheme)Short Note · 3 marks
- 12Radioactive Iodine2024 March (Supplementary) (2010 Scheme)Short Note · 3 marks
- 13Anti thyroid drugs2014 September (Supplementary) (2010 Scheme)Short Note · 3 marks
- 14Lugol’s Iodine is given for 10 days prior to thyroidectomy surgery for Grave’s
disease.2023 July (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 15Anti-thyroid drugs2018 July (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 16Explain the use of propranolol in thyrotoxicosis.2018 February (2010 Scheme)Short Answer · 1 mark
- 17Methimazole acts by:2024 December (Supplementary) (2019 Scheme)MCQ · 1 mark
- 18Antithyroid drugs2013 April (2010 Scheme)Short Answer · 1 mark
- 19Drug used in thyrotoxic crisis2014 March (2010 Scheme)Short Answer · 1 mark
- 20Propylthiouracil2025 August (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 21Anti- thyroid drugs safe during pregnancy2017 August (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 22Thyrotoxic crisis.2015 September (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 23Anti thyroid drugs2016 October (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 24Radioactive iodine2020 February (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 25Use of Propranolol in Thyrotoxic crisis.2024 March (Supplementary) (2010 Scheme)Short Answer · 1 mark
- 26The preferred drug for her is:2024 December (Supplementary) (2019 Scheme)MCQ · 1 mark
- 27 Carbimazole for treatment of Thyroid storm2024 August (Supplementary) (2010 Scheme)Short Answer · 0.3 marks
- 28Antithyroid drugs2019 February (2010 Scheme)Short Answer · 0.3 marks
