Pharmacology: Anti-thyroid drugs,its classification & mechanism of action.

1. TOPIc
Anti-thyroid drugs
BY
YOGESH KUMAR
H.O.D.(Head of Department)
Nlpd professional institute barabanki,
U.P.,INDIA.
PHARMACOLOGY

2. Anti-thyroid drugs
• These are the drugs used in the treatment of hyperthyroid
condition.
• These drugs acting by reducing thyroid hormone
synthesis or release or both.
• An Antithyroid agent is a hormone antagonist acting upon
thyroid hormones. The main antithyroid drugs are
carbimazole, methimazole, and propylthiouracil.

3. 1. Inhibits thyroid hormone synthesis - Propylthiouracil
- Methimazole
- Carbimazole.
2. Inhibitors of Iodide trapping - Thiocyanates
- Perchlorates
- Nitrates.
3. Inhibits thyroid hormone release - Iodine
- Iodides of Na
- Organic iodides
4. Destroy thyroid tissue – I131 , I125 , I123
5. Others - Propranolol
- Atenolol
- Diltiazem
- Ipodate.
classification

4. 1. Inhibits thyroid hormone synthesis-
 These are also called Thioamides.
 They inhibit thyroid peroxidase enzyme.
 They also inhibit coupling of Iodotyrosines(Monoiodotyrosine
& Diodotyrosine).
 Skin rashes are the most common side effects.
2. Inhibitors of Iodide trapping-
 They are also called Ionic inhibitors.
 Thiocyanates, Perchlorates & other anions block update
iodide by thyroid. They are highly toxic & are not used.

5. 3. Inhibits thyroid hormone release -
 These drugs are fastest acting Anti-thyroid drugs.
• Iodine 7 iodides-
 High concn of iodide appears to inhibit almost all steps
in the synthesis of thyroid hormones & also their
release.
Uses-
 Lugol’s iodine (5% iodine in 10% solution of KI)
 As an expectorant: KI used as mucolytic agent.

6.  As an antiseptic: Tincture of iodine (iodine in alcohol).
4. Destroy thyroid tissue –
These are radioactive istopes.
Therapeutically used radioactive iodine is I131 .
They are acting by destroying thyroid cells.
 I131 is used orally as solution or capsule.

7. Mechanism of action of Anti-thyroid drugs

8. THANK YOU