Presentation on theme: "Iodine It is important for two reasons :- 1- It has pharmacological actions :- fibrolytic agent, expectorant and bactericidal agent. 2- It has a biochemical."— Presentation transcript:
Iodine It is important for two reasons :- 1- It has pharmacological actions :- fibrolytic agent, expectorant and bactericidal agent. 2- It has a biochemical role in thyroid hormons formation. It is essential for the synthesis of two thyroid hormons. Iodine deficiency result in enlargment of thyroid gland,characterized by swelling at neck. In which the body attempts to substitute iodine deficiency by increasing thyroid gland size. Potassium iodide ( 0.01%) is added to table salts to compensate iodine deficiency.
Thyroid hormons synthesis Thyroid hormons synthesis Iodine in the thyroid gland is found as iodide form( I - ). 2 I - I 2 Peroxidase H2O2H2O2 I 2 + HO- -CH 2 CHCOOH NH 2 HO- -CH 2 CHCOOH I I I Diiodotyrosine HO- -CH 2 CHCOOH Monoiodotyrosine Tyrosine I
HO- -CH 2 CHCOOH + HO- -CH 2 CHCOOH HO- -O- -CH 2 CHCOOH NH 2 I I I I I I I I I I I Diiodotyrosine Thyroxine (T4) HO- -CH 2 CHCOOH HO- - O- -CH 2 CHCOOH Diiodotyrosine NH 2 I I I I I II I I Monoiodotyrosine 3,5,3, triiodothyronine(T3) active 3,3,,5, triiodothyroxine inactive
Iodine adminstration Orally used iodine is converted to iodide ion in the intestenal tract : - I 2 2I -- reduction Uptake of used iodine is governed by three fectors 1- Nature of thyroid tissues,uptake of tumorous thyroid tissues is lower than normal. 2- High iodide level lowers uptake of iodine dose. 3- Thyrotropine level in blood, since it is secreted by anterior pituitary and has effect on using iodine.
Clinical uses of iodide 1- Improving agent in hyperthyrodism :- a- Acting on lowering the release of the hormon. b- Causing involution of the gland and increasing the bond iodine. c- Usind iodine to remove hyperthyrodism symptoms. 2- Fibrolytic agent : - Used in syphlis, fungal infections, actinomycosis and blastomycosis.
3- As expectorant : - Iodides are used in treatment of asthma, chronic bronchitis and late stage of acute bronchitis. Iodide side effects :- 1- Iodism :- irritative effects on skin and mucosa membrane such as coryza,rashes,headache, conjuvtivitis and laryngitis. 2- G.I.effects : nausea,vomiting & diarrhea. 3- Used in skin infections requires opening up.
Official iodine products 1- Iodine : M.Wt Heavy gray-black granules. Slightly soluble in H 2 O. Soluble in chloroform,CCl 4 and ether. Lugols, solution : 5 gm iodine and 10 gm KI per 100ml total volume. Dose ml 3 times/day 2- Potassium iodide ( KI), M. wt. 166 Colorless crystals, neutral or alkaline to litmus & soluble in H 2 O,glycerin and alcohol. KI solution : contains 100gm KI in 100ml solution. Sodium thiosulfate is added to reduce libration of iodide from KI.
2Na 2 S 2 O 3 + I 2 Na 2 S 4 O 6 + 2NaI Dose : oral 0.6 ml / daily 3- Sodium Iodide : NaI Colorless,odorless crystals, soluble in H 2 O,alcohol & glycerin. Used in hyperthyroid condition. Dose : - oral 300 mg 2-3 times/daily Intravenous infusion 1 gm-3gm/daily