Thyroid Gland

Question 1

Thyroid hormone preparation

Answer 1

Levothyroxine

Question 2

Antithyroid agents

Answer 2

Thiomazole (methimazole), propylthiouracil

Question 3

Iodide is oxidised to iodine by enzyme

Answer 3

Thyroid peroxidase

Question 4

Iodine is added into

Answer 4

Tyrosine residue called thyroglobulin

Question 5

Thyroid peroxidase also does

Answer 5

Conjugation of monoiodothyroxine and DIT to form T3 ;2 DIT conjunction to form thyroxine(T4)

Question 6

T3 and T4 are released when

Answer 6

Thyroglobulin is proteolysed

Question 7

10 %of T3 is formed from thyroid gland remaining 90from

Answer 7

T4from deiodisation done by iodothyronine deiodinase

Question 8

Is T3or T4more active

Answer 8

T3 is 10x more active than T4

Question 9

Fns of thyroid gland

Answer 9

Responsible for basic energy metabolism, Growth of body and development, Metabolism(increase gluconeogenesis and decrease glycogen synthesis, Nervous system dev and fn, stimulate beta adrenoreceptor expression in myocardium and increase catecholamine sensitivity in myocardium -increase O2 consul

Question 10

Hypothyroidism

Answer 10

Decrease in thyroid hormones and their fn

Question 11

In women hypothyroidism is usually

Answer 11

Subclinical and hormone replacement therapy is used

Question 12

Hypothyroidism causes

Answer 12

Hyperthyroidism treatment, autoimmune thyroiditis, thyroid gland surgery, medication like amiodarone and lithium

Question 13

Hyperthyroidism causes

Answer 13

Graves disease(Bazedovs), nodular toxic goiter

Question 14

Treatment of hyperthyroidism

Answer 14

Radioactive iodine therapy or thyrostatic drug therapy (prevent iodine binding to thyroglobulin

Question 15

Thyroxine synthesis occurs only in

Answer 15

Low iodine concentration, otherwise it inhibits

Question 16

Thyrotropin releasing Hormone(TRH) and Thyroid stimuting hormone (TSH )other names

Answer 16

TRH:Thyroliberin,TSH: Thyrotropin

Question 17

Carbimazole is a

Answer 17

Thiomazole prodrug

Question 18

For symptomatic treatment of hyperthyroidism,use

Answer 18

Beta adrenoreceptor blocker

Question 19

Levothyroxine (synthetic form of T4) action

Answer 19

On conversion to T3, stimulate intracellular thyroid receptors all over body-nuclear DNA ,gene expression and protein synthesis follows

Question 20

Use of levothyroxine

Answer 20

Hypothyroidism, autoimmune hashimoto’s thyroiditis, replacement therapy after thyroidectomy

Question 21

SE of levothyroxine

Answer 21

Tachycardia

Question 22

Interactions of levothyroxine with

Answer 22

drugs like amiodarone and diet

Question 23

Timing for levothyroxine

Answer 23

60 min before first meal and no other medications within 2 to 4 hours after administration

Question 24

Levothyroxine reduce the effect of

Answer 24

Hypoglycemic agents

Question 25

Mild intoxication of thyroid hormone caue

Answer 25

Sinus tachycardia, tremor, anxiety feeling of heat, agitation, sleep disorders

Question 26

Severe toxicity of thyroid hormone cause

Answer 26

Supraventricular tachycardia, hyperthermia, hypertension and finally seizures and coma

Question 27

Symptoms of acute levothyroxine overdose comes Only after

Answer 27

Approx 7 days delay due to T4 to T3 conversion time

Question 28

Do we use antithyroid hormones in thyroid overdose?

Answer 28

No, only symptomatic treatment and on case of severe adreno stimulation use BAB

Question 29

Thiomazole ((methimazole) action

Answer 29

Inhibit thyroid peroxidase and it's fns

Question 30

Thiomazole is

Answer 30

Embryotoxic, because it crosses placenta ( category D)

Question 31

Propylthiouracil action

Answer 31

Inhibit thyroid peroxidase and iodothyronine deiodinase and their fns.Its 10 times weaker than thiomazole,so used during first trimester of pregnancy)

Question 32

Use of propylthiouracil and thiomazole

Answer 32

Hyperthyroidism (Graves/ Bazedovs Disease)

Question 33

SE of propylthiouracil

Answer 33

Allergic skin reactions, agranulocytosis