Pathology EMQ template.

Name: Nick Perry

Candidate number:

Theme: Chemical Pathology

 

OPTION LIST

 

A	Amiodarone	I	Levothyroxine sodium
B	Amitriptyline	J	Lithium carbonate
C	Amlodipine	K	LMW heparin
D	Amoxicillin	L	Omeprazole
E	Carbamazepine	M	Potassium iodide
F	Carbimazole	N	Propranolol
G	Ceftriaxone	O	Propylthiouracil
H	Digoxin	P	Sertraline

 

 

For each scenario below, choose the most appropriate answer from the list above. Each option may be used once, more than once or not at all.

 

1. A 31 year old American, concerned that a radioactive plume might travel across the Pacific from Fukushima, presents to her physician’s office in LA with parotid gland swelling, diarrhoea and a metallic taste in her mouth. What drug has she been taking (probably to excess)?

 

 

2. A 28 year old female complains of tiredness, weight gain and a lump in her neck.  Serum levels of T4 are low.  She started taking new medication 1 year ago following a suicide attempt.  Which drug is most likely to be responsible for her present condition?

 

 

3. A 68 year old male who was discharged from the Coronary Care Unit 3 months ago is being reviewed by his GP. He is constipated, more tired than usual and bradycardic. Blood tests show low FT4, low total T3 and raised TSH. Which drug is most likely to be responsible?

 

 

4. A 59 year old female has been admitted into hospital for a chest infection. After her first doses of medication were given the FY1 sent off blood samples which came back showing significantly raised levels of FT4.  Levels returned to normal the following day. Which drug can explain these findings?

 

 

5. A 45 year old female is being treated for a large euthyroid goitre. She is now experiencing heart palpitations, abdominal pain and anxiousness.  Which drug is she taking?

 

 

 

ANSWERS

1. M

2. J

3. A

4. K

5. I

 

 

Notes:

 

1.   Potassium iodide has been approved to protect thyroid glands from radioactive iodine, a common product of nuclear fission. KI saturates the body with stable iodide prior to exposure, helping to prevent uptake of radioiodine by the thyroid.

2.   This patient has bipolar disorder and is taking the mood stabilizer, lithium.  Hypothyroidism has been reported in 5-20% of people taking lithium; a smooth nontender goiter is observed in up to 60%. Lithium is concentrated in the thyroid gland and interferes with thyroid hormone synthesis and release. Lithium also increases thyroid autoimmunity if present before therapy.

3.   Amiodarone contains 37.5% iodine by weight. It may cause hyper- or hypothyroidism, but iodide-induced hypothyroidism is more common. The most likely mechanism is that the thyroid is unable to escape the acute Wolff-Chaikoff effect after an iodine load and to resume normal thyroid hormone synthesis. Amiodarone has a long half-life, so effects may be seen weeks or months after administration.

4.   Low molecular weight heparin is routinely given to protect against thrombosis whilst in hospital.  Heparin increases lipoprotein lipase activity and markedly increases free T4 levels as T4 is displaced by free fatty acids. To avoid misleading lab results, thyroid tests should be measured before or >10 hours after administration of LMWH.

5.   This patient has been taking levothyroxine to reduce the size of her euthyroid goitre. This drug decreases TRH and TSH.  If the dose is too high, patients may develop hyperthyroidism.