Antacids and antihistamines - class-XII

An antacid is a substance which neutralises stomach acidity and is used to relieve heartburn, indigestion or an upset stomach.

• An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach.
  
• It is also used to relieve symptoms of extra gas such as belching, bloating, and feelings of pressure/discomfort in the stomach/gut. Aluminum and magnesium antacids work quickly to lower the acid in the stomach.
  
• Generally $NaHCO _3$ and $Mg(OH) _2$ are used in antacid medicinal preparation.

Cimetidine is a histamine $H _2$-receptor antagonist, that inhibits stomach acid production. It is largely used in the treatment of heartburn and peptic ulcers. So it acts as an antihistamine.

Climetidine is an antacid which suppress secretion of HCl.

Milk of magnesia consists of Magnesium hydroxide.

Antacid are drugs or medicines used to prevent or correct acidity, especially in the stomach.
Examples are Cimetidine, Ranitidine, etc.

An antacid (derived from the word "anti-acid") is a substance which neutralizes stomach acidity, which in turn relieves heartburn, indigestion or stomach upset.
Histamine and cimetidine are examples of antacids.

Cimetidine (also called Tegamet) was the largest selling antacid.
It prevent the interaction between histamine and the receptors in the stomach wall, releasing less amount of acid.

Examples of antacid include sodium bicarbonate, magnesium hydroxide, magnesium carbonate and aluminium hydroxide, as they are all basic in nature.

Most commonly used antacids are weak bases.
Examples of antacid includes sodium bicarbonate, magnesium hydroxide, magnesium carbonate and aluminium hydroxide. An antacid is the substance which neutralizes the acid and raise the pH to an appropriate level in stomach. They should not be caustic like strong bases.

An antacid is the substance which neutralizes the acid and raises the pH to an appropriate level in stomach. In other words, antacid is a base which neutralizes excess of acid in the stomach. Examples of antacid include sodium bicarbonate, magnesium hydroxide and aluminium hydroxide. They control the symptoms and not the cause.

Antacid is a drug (or medicine) preventing or correcting acidity, especially in the stomach.
To neutralize the acid in stomach, antacid should be basic in nature.
All three can be used as antacids since they are basic in nature.

Antacid is a chemical substance which removes excess acid and raises the pH to an appropriate level in stomach, preventing heatburn and upset stomach,

Omeprazole is the recently developed antacid which is used to prevent the formation of acid in the stomach.

An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach.

$(B)$ Lansoprazole

The drug cimetidine (Tegamet), was designed to prevent the interaction of histamine with the receptors present in the stomach wall. This resulted in release of lesser amount of acid. The importance of the drug was so much that it remained the largest selling drug in the world until another drug, ranitidine (Zantac), was discovered.

The total milliequivalents of HCl = 200 mL * 0.1 M = 20 meq. The excess HCl neutralized by 90 mL of 0.1 N base = 9 meq. Therefore, the HCl consumed by the antacid = 20 - 9 = 11 meq. Since aluminum hydroxide is the only base, it must have neutralized 11 meq of HCl.

Antacids are basic substances used to neutralize excess stomach acid (HCl) to relieve symptoms of indigestion or heartburn.

The pollen triggers these cells in nasal chambers, causing them to release histamine and the other chemicals. Histamine dilates the small blood vessels of the nose and fluids leak out into surrounding tissues causing allergy symptoms.

Antacids: Tension and mental stress escalate the level of acid in bile juice. This hyperacidity can be combated using bases like calcium carbonate, magnesium hydroxide or aluminium hydroxide in the form of tablets or aqueous suspensions. These react with hydrochloric acid in the stomach and neutralize it partially. Gelusil and Digene are two examples of antacids. Antacids must be basic but not enough to make it caustic. Hence, options B and C are appropriate.

$Mg(OH) _2$ is used as an antacid to neutralize the acidity in the stomach.

Antacids neutralize the acid made by your stomach, curing various problems like heartburn, upset stomach, etc. Generally, they do not have any side effects.

An antacid is a substance which neutralizes stomach acidity, which in turn relieves heartburn, indigestion or stomach upset.
All of these are the examples of antacids.

Antihistamine is a drug that inhibits the physiological effects of histamine, used especially in the treatment of allergies.

Ranitidine is also called as zinetac. It is an antihistamine.
It prevent the interaction between histamine and the receptors in the stomach wall, releasing less amount of acid.

Antihistamine is a drug or other compound that inhibits the physiological effects of histamine, used especially in the treatment of allergies.
Brompheniramine is an antihistamine drug.
Rantidine and Cimetidine are antacids.

Antihistamines are drugs which treat allergic rhinitis and other allergies. Antihistamines can give relief when a person has nasal congestion, sneezing, or hives because of pollen, dust mites, or animal allergy. Typically people take antihistamines as an inexpensive, generic, over-the-counter drug with few side effects. As an alternative to taking an antihistamine, people who suffer from allergies can instead avoid the substance which irritates them. However, this is not always possible as some substances, such pollen, are carried in the air, thus making allergic reaction caused by them generally unavoidable.

Iproniazid (Marslid, Rivivol, Euphozid, Iprazid, Ipronid, Ipronin) is a non-selective, irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine class. It is a xenobiotic that was originally designed to treat tuberculosis, but was later most prominently used as an antidepressany drug.

The assertion that Penicillin (G) is an antihistamine is incorrect. Penicillin (G) is an antibiotic. It is a narrow spectrum antibiotic. Hence it effective against both gram positive as well as Gram negative bacteria. Therefore, the Reason is correct.
Hence, option E is the right answer.