Expectorants And Emetics Notes

Expectorants And Emetics Introduction

Cough, a protective reflux (both voluntary and involuntary) helps to expel irritant matter from the respiratory tract. When a person coughs there is a short intake of breath and the larynx closes momentarily.

It is a vital part of the defence mechanism. It can be caused by infections, chemical irritants, asthma, lung tumour, breathing in dust particles. It is of two types

Productive Cough: A productive cough produces a phlegm or mucus (sputum). The mucus may have drained down the back of throat from the nose or from the lungs. A protective cough should not be supressed. It clears mucus from the lungs.

Irritative or Non-productive cough: A non-productive cough does not produce sputum. A dry, hacking cough may develop towards the end of a cold or after exposure to an irritant such as dust and smoke.

Expectorant

The latin word ‘Expectorate’ means ‘to drive from the chest’. Expectorants are drugs used to help in the removal i.e. explusion of secretions or exudate from the trachea, bronchii or lungs. Hence, they are used in the treatment of cough. They act upon the respiratory tract in two ways

By decreasing the viscosity of the bronchial secretion and facilitating their elimination;local irritants are expelled and ineffectual coughing is required.

By increasing the amount of respiratory tract fluid, a demulcent action is exerted on dry mucosal lining & relieving the unproductive cough.

Inorganic saline expectorants are:- Ammonium salts (Ammonium Chloride), iodide (Potassium/Sodium Iodide), citrates and Antimony Potassium Citrate.

Read and Learn More Pharmaceutical Inorganic Chemistry Notes

Potassium Iodide

Chemical Formula: KI                 Molecular Weight:166.01

Synonyms: Kalii Iodidum, Pot. Iod.

Method of Preparation

It is prepared by treating iron filling with iodine under water to get iodide which is then reacted with potassium carbonate.

Hydroiodic acid when treated with potassium bicarbonate results in the formation of potassium iodide.

Properties

It occurs as odourless, transparent or opaque crystals. It is white granular powder. It is slightly hygroscopic, taste is saline and slightly bitter.

It is very soluble in water and even more so in boiling water, freely soluble in glycerine and soluble in alcohol. On long exposure to air it becomes yellow due to liberation of iodine and small quantity of iodate may be formed.

Iodine readily dissolves in an aqueous solution of potassium iodide, forming a dark brown solution which contains potassium iodide.

Uses

It is used as an ingredient of expectorant mixture. It may be used for the prophylaxis and treatment of simple goitre. It is used as an antifungal agent in veterinary practise. Potassium
iodide solution is used as iodine supplement.

Ammonium Chloride

Chemical Formula: NH₄Cl                 Molecular Weight: 53.49

Synonyms:

Ammonium Muriate, Sal Ammoniac, Salmiac, Amchlor, Ammon. Chlor.

Ammonium chloride occurs naturally in volcanic regions, forming on volcanic rocks near fume releasing vents.

Method of Preparation

It is a product of the Solvay Process used to produce Ammonium Chloride and Sodium Carbonate.

This method is used to minimize ammonia release in some industrial operations. Ammonium chloride is prepared by combining ammonia with either hydrogen chloride (gas)
or hydrochloric acid.

Properties

It is a white crystalline salt, highly soluble in water. Solutions of ammonium chloride are mildly acidic. It is somewhat hygroscopic. It is odourless and possesses cooling saline taste.
On heating, it sublimes without melting.

Ammonium chloride reacts with a strong base e.g. sodium hydroxide to release ammonia gas.

Ammonium chloride also reacts with alkali metal carbonates at elevated temperatures, giving ammonia and alkali metal chloride.

Storage

It should be stored in tightly closed containers because it is hygroscopic.

Assay

A modified Volhard’s method was used in I.P. 66. A solution of the substance acidified with nitric acid, is shaken with a measured yohjme of N/10 AgNP₃, nitrobenzene being previously added.

Nitrobenzene is added to coagulate the precipitiate of AgCl, so that it will not interfere with the titrated later of excess of AgNO₄ which is determined by titratio with N/10 ammonium thiocyanate, using ferrric ammonium sulphate as indicator.

The following is the reaction taking place at the end point when red ferric thiocyanate is formed.

Uses

Ammonium chloride is a nitrogen source in fertilizers e.g. chloro ammonium phosphate. It is used as an expectorant in cough medicine. Its expectorant action is caused by irritative action on the bronchial mucosa.

Ammonium chloride is used as a systemic acidifying agent in treatment of severe metabolic alkalosis. It is also used as an flavouring agent It is used in the textile and leather industry in dyeing, tanning, textile printing and to luster cotton. It is used in hair shampoos as a thickening agent.

Emetics

An emetic is a drug that produces vomiting. Vomiting is the involuntary, forceful expulsion of the content of one’s stomach and sometimes the nose. Emetics act either directly or by stimulation of the chemeoreceptor trigger zone in the floor of IV th ventricle in medulla or reflexly by irritant action on gastro-intestinal tract.

It is used medically where a substance has been ingested and must be expelled from the body immediately. Gastric secretions and likewise, vomiting are highly acidic. Salt water and mustard water have been used since ancient times as emetic Hydrogen peroxide is used as an emetic in veterinary practise Inorganic compounds e.g.

Copper sulphate, Sodium chloride, Zinc sulphate and Potassium antimony tartarte belong to the latter type. Emetics should be avoided in children and in the elderly pregnant women and in patients suffering from CNS depression, unconscious or in coma.

If the vomiting reflex continues for an extended period, dehydration, hypokalaemia and alkalosis may occur and replacement of fluid and electrolytes may be necessary. Emetics are also sometimes used in the preparation of cough syrups.

Copper Sulphate

Synonym: Blue vitriol

Chemical Formula: CuSO₄.5H₂O

Molecular Weight: 159.6

Preparation:

It is prepared by dissolving cupric oxide (or) cupric hydroxide (or) cupric carbonate in dilute H₂SO_4.

Properties

Its hydrated salt is blue in colour but anhydrous salt is colourless. It readily dissolves in water but is insoluble in alcohol.

Uses

It is used as a germicide and insecticide in agriculture. A mixture of copper sulphate and lime, commonly known as Bordeaux mixture, is used as fungicide. It is used in electroplating, calico printing and in electrical batteries.

Assay:

Weigh accurately 1 gm of copper sulphate (CuS0₄) in 50 ml of water, add 3 gm of potassium iodide, 5 ml of acetic acid and titrate the liberated iodine with 0.1 N Sodium thiosulfate (Na₂S₂O₃) using solution of starch as indicator.

Sodium Potassium Tartrate

Synonyms: Rochelle salt

Chemical Formula: C₄H₄NaKO₆

Molecular Weight: 210.158

Properties

It occurs as colourless crystals, saline in taste, soluble in hot water and insoluble in alcohol.

Uses:

It is used as laxative. It has also been used1in the process of silvering mirrors.

Expectorants And Emetics Very Short Answer Questions

Question.1 What do you understand by the term ‘Cough’?
Answer: Cough, a protective reflux (both voluntary and involuntary) helps to expel irritant matter from the respiratory tract.

Question.2 How many types of cough are there?
Answer: There are two types of cough :
1) Productive cough
2) Non-productive cough/Irritant cough

Question.3 Define Expectorants?
Answer: Expectorants are drugs used to help in the removal or explusion of secretions or exudate from the trachea, bronchii or lungs.

Question.4 Name any two inorganic compounds which are used as Expectorants?
Answer: 1) Ammonium salts such as Ammonium chloride
2) Iodide such as Potassium Iodide.

Question.5 How do expectorants act upon the respiratory tract?
Answer: Expectorants act upon the respiratory tract in two ways :

1. By decreasing the viscosity of the bronchial secretion and facilitating their elimination; local irritants are expelled and ineffectual coughing is required.
2. By increasing the amount of respiratory tract fluid, a demulcent action is exerted on dry mucosal lining and relieving the unproductive cough.

Question .6. What is the difference between emetic and vomiting?
Answer. An emetic is a drug that produces vomiting while vomiting is the involuntary; forceful expulsion of the contents of one stomach and sometimes the nose.

Question.7. Name two inorganic compounds which are used as emetics?
Answer. Copper sulphate, Zinc sulphate
Sodium chloride Potassium antimony tartrate

Question.8. What is the molecular formula of antimony potassium tartarte?
Answer. Molecular formula of antimony tartarte is C₄H₄O₇SbK.1/2H₂O.

Question.9. Which inorganic compound is used in the prevention and treatment of goitre?
Answer. Potassium iodide.

Question.10. What is the difference between productive cough and non-productive cough?
Answer. Productive cough produces a phlegm or mucus (sputum) while non-productive cough does produce sputum.

Question.11. How do emetics act?
Answer. Emetics act either directly or by stimulation of the chemeoreceptor trigger zone in the floor of IVth ventricle in medulla or refluxly by irritant action on gastro intestinal tract.

Question.12. What is the method of preparation of Ammonium Chloride?
Answer. Ammonium chloride is prepared by reacting ammonium with sodium chloride

Question.13. Which expectorant is prepared by Solvay process?
Answer. Ammonium chloride.

Question.14. What is the other name of Kali Iodidum?
Answer. Kali iodidum is also known as Potassium Iodide.

Question.15. What is the structural formula of Antimony Potassium Tartrate?
Answer. Structural formula of Antimony potassium tartrate is

Question.16. What is the othei name of Antimony Potassium Tartrate?
Answer.

1. Tartarised antimony
2. Potassium antimonyl tartrate

Question.17. What are the Pharmaceutical uses of Potassium Iodide?
Answer: Potassium iodide is used as an ingredient of expectorant mixture. It is also used as an Iodine supplement.

Expectorants And Emetics Fill In The Blanks

1. Cough is a……………. reflux.

Answer: Protective

2. Emetics are used to produce…………………………..

Answer: Vomiting

3. Ammonium chloride is prepared by…………………

Answer: Solvay process

4. The latin word ‘expectorate’ means …………………….

Answer: To drive from the chest

5. Productive cough produces a…………………..

Answer: Mucus

6. Expectorants are used to help in the…………………

Answer: Removal of secretions

7. ………………….inorganic compound are used as saline expectorants.

Answer: Potassium iodide/ammonium chloride

8. Ammonium chloride is also known as ‘………………………

Answer: Ammonium Muriate/Amchlor

9. Antimony potassium tartarte is also known as…………………….

Answer: Emetic tartarte/Tartarised antimony

10………………….is used as an emetic in verterinary practise.

Answer: Hydrogen Peroxide

11………………….is used as emetic in ancient times.

Answer: Salt water/Mustard water

12. Solutions of ammonium chloride is highly…………..

Answer: Acidic

13. Ammonium chloride is………………in nature.

Answer: Hygroscopic

14. Potassium iodide is prepared by treating……… with………….under water.

Answer: Iron fillings with iodine

15. Ammonium chloride is used as………………in fertilizers.

Answer: Nitrogen source

Expectorants And Emetics Multiple Choice Questions

1. Productive cough produces.

1. Mucus
2. Vomiting
3. Amalgam
4. None of these

Answer: Mucus

2. Which cough does not produce mucus?

1. Productive cough
2. Both a) and c)
3. Non-productive cough
4. None of these

Answer: Non-productive cough

3. Which inorganic compound is used as Emetic?

1. Ammonium chloride
2. Potassium antimony tartarte
3. Potassium iodide
4. Potassium citrate

Answer: Potassium iodide

4. ‘KI’ stands for

1. Potassium iodide
2. Potassium iodate
3. Potassium citrate
4. None of these

Answer: Potassium iodide

5. Emetics act

1. By stimulation of the chemeoreceptor trigger zone
2. By increasing the amount of fluid
3. By decreasing the viscosity of the bronchial secretion
4. None of these

Answer: By stimulation of the chemeoreceptor trigger zone

6. If the vomiting reflex continues for an extended period,……….occurs.

1. Dehydration
2. Alkalosis
3. Hypokalemia
4. All of the above

Answer: All of the above