Chemistry affects almost every sphere of life and its principles have been used for the benefit of human beings. Such as soaps for cleaning, detergents, detergents and bleaches etc., chemicals used in making and coloring the threads of textiles, various polymers used for domestic use, are the products of chemistry. Similarly, different chemicals are used directly or indirectly in various types of drugs, explosive materials, fuels, rocket propellants, building materials and electrical equipment materials etc.

Man himself is a beautiful chemical creation and all our activities are also governed by different types of chemicals. Therefore, as a conclusion, it can be said that without chemistry our life is almost impossible, although it also has some disadvantages.

Therapeutic Action of Different Classes of Drugs

In this section we will describe antacids, antihistamines, neuroactive drugs, antimicrobials and anti-inflammatory drugs.

Antacids

Consumption of excessive amounts of tea, coffee, pickles and allopathic medicines by humans increases the production of acid in the stomach, which causes extreme pain and sometimes ulcers also occur in the stomach. Anti-acids are used to reduce this acidity of the stomach. Therefore, those chemical substances which are used to reduce the acidity of the stomach are called antacids. Initially, acidity was treated with sodium hydrogencarbonate (NaHCO₃) or aluminum and magnesium hydroxides [Al(OH)₃ and Mg (OH)₂ ] but due to the high concentration of NaHCO₃ the stomach becomes alkaline, due to which more acid is produced. it happens. Therefore, metallic hydroxides are considered good antacids because they are insoluble so that the pH value does not exceed 7 (neutral).

Inofructsalt is also a commonly used antacid that is used with water. All the above antacids do not cure the cause of the disease, only the symptoms of the disease are controlled, so having an excessive amount of ulcers can be fatal. For this reason, earlier only the diseased part of the stomach was removed. Nowadays herbal antacids like Pudin Hara are also used. Further research revealed that cimetidine and ranitidine (Zantac) are effective antacids. Histamine interacts with receptors located in the walls of the stomach, thereby increasing the production of pepsin and hydrochloric acid in the stomach, which is used to prevent the drug cimetidine. But nowadays ranitidine is used in maximum quantity in the form of antacid. Omeprazole and lansoprazole are also currently being used as antacids.

Antihistamines

Antihistamines are chemical substances that reduce the effect of itching and burning on the skin. Histamine is a vasodilator substance that constricts the muscles of the respiratory tract and esophagus and softens the walls of blood vessels. Nasal congestion caused by colds and allergies caused by pollen grains are also caused by histamine. Antihistamines interfere with the natural action of histamine. Antihistamine binds to the binding surface of the receptor on which histamine exerts its effect, i.e.

there is competition between histamine and antihistamine for this binding surface. The synthetic drugs called brompheniramine (Dimetep) and terfenadine (Celden) act as antihistamines. Antihistamines do not affect gastric acid secretion because antiallergic and anti-acid drugs act on different receptors.

Neurologically Active Drugs

Tranquilizers and Analgesics are neuroactive drugs. They affect the mechanism of transmission of messages from the nerve to the receptor.

(a) Tranquilizers

Those drugs relieve mental stress without sleep, they are called Prashantaks. Therefore tranquilizers are used in stress and mental illnesses. Tranquilizers relieve anxiety, tension, irritability or excitement and are a major component of sleeping pills. There are different types of Tranquilizers and they work through different mechanisms. For example, noradrenaline is a neurotransmitter that causes changes in mood.

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When the amount of noradrenaline decreases due to some reason, the signaling process slows down and the person becomes depressed. In this situation, anti-depressant medicine is required. This drug inhibits an enzyme that causes the degradation of noradrenaline. When this enzyme is inhibited, this neurotransmitter can slowly metabolize and activate its receptor over a longer period of time, reducing the effects of depression. Ipronizid and phenalgin nardil) are two important tranquilizers.

Chlordiazepoxide and meprobamate are relatively mild tranquilizers. Equinil is used to relieve depression and stress. Derivatives of barbituric acid or malonyluria are the main drugs in this class. Many drugs are made from the difference between R and R’, which are called barbiturates or barbitales. Using them makes you sleepy. That is, they are sleepy. Examples: Veronal, Valium, Serotonin, Amytel, Reserpine, Nembutal, Luminal and Seconel. Of these, Valium is most commonly used as a sedative.

(b) Analgesics

Medicines that reduce or eliminate pain without irritating the nervous system are called analgesics. There is no effect on the consciousness, coordination and mental state of a person due to pain relief and it does not cause paralysis either. Like tranquilizers, analgesics are also neurologically active drugs.

There are two types of Analgesics

(i) non-addictive (non-attachment or non-addictive) Analgesics
(ii) narcotic (narcotic or analgesic) Analgesics

(i) Non-addictive (Non-attachment or Non-addictive) Analgesics

These analgesics reduce pain but they are not addictive, that is, the person is not addicted to them. The main examples of non-narcotic analgesics are aspirin and paracetamol. Nowadays ibuprofen and dichlorofenac sodium are also used as analgesics.

Aspirin is used to reduce the synthesis of chemicals called prostaglandins that cause inflammation and pain in the tissues. Apart from this, aspirin also reduces the pain caused by rheumatism. Aspirin also has other functions, such as reducing fever (antipyretic), inhibiting platelet coagulation, preventing blood clotting. For this reason, aspirin is also used to prevent heart attacks. Aspirin should not be taken on an empty stomach, as it increases the acidity of the stomach, which can lead to bleeding due to scarring of the internal membrane. Phenacetin and Paracetamol are also antipyretic drugs. Sweating reduces fever by taking antipyretic drugs.

(ii) Narcotic (Narcotic Or Analgesic) Analgesics

These reduce the agonizing pain but they also cause sleepiness and unconsciousness. Consumption of these excessive amounts causes effects like stupor, coma (convulsions) and convulsions and in the end, death can also occur. Morphine is an important narcotic analgesic, also called opiates (Ahiphene) because they are obtained from poppy (Opium poppy). These analgesics are mainly used to relieve heart pain, post-operative pain, labor pain, and late-stage cancer. With the use of these painkillers, man becomes accustomed to them. Heroin and codeine are also important narcotic analgesics. Heroin is made by the acetylation of morphine and is a powerful analgesic.

(c) Antimicrobials

In humans and other organisms, various diseases are caused by micro-organisms such as bacteria, viruses and fungi. Antimicrobials are drugs that selectively kill or inhibit the growth or growth of bacteria, fungi, viruses or parasites or the parasitic effect of microorganisms. Antibacterial, Antifungal, Antivirus and Antiparasite destroy bacteria, fungi, viruses and parasites respectively.

Antibiotics are of the following types

(i) Antibiotics
(ii) Antiseptic and disinfectant

(i) Antibiotics

Antibiotics are drugs that are produced by micro-organisms such as bacteria (viruses) and fungi (mildew) and that inhibit the growth or destruction of other microorganisms by inhibiting their metabolic processes. Antibiotics are obtained through complete or partial chemical synthesis. They are used in low concentrations and are less toxic, so they are used to treat infections. In the nineteenth century, chemicals were discovered that adversely affect the invading bacteria, but the host (host). ) but they have no effect. The following are examples of antibiotics.

The arsenic-based drug Arsphenamine (Salvarsan) used for the treatment of syphilis was discovered by Paul Erlish. Salvarsan is toxic to humans, but its effect is greater on the bacterium (spirochetes) that cause syphilis than on humans.

Prontosil is an antibiotic which is converted in the body to sulfanilamide which is the actual effective sulfa drug.

Sulfapyridine is the most effective antibiotic among sulfa drugs.

Following the success of sulfonamides, in 1929, Alexander Fleming discovered penicillin, an antibiotic drug from a fungus called Penicillium notatum, whose general formula is as follows.

Before giving penicillin, it is necessary to test for allergy to it. Antibiotics kill or inhibit the growth of micro-organisms. The following are examples of some bactericidal and bacteriostatic antibiotics.

Bactericidal	Antibacterial
Penicillin	Erythromycin
Aminoglycoside	Tetracycline
Ofloxacin	Chloramphenicol

The range of bacteria or other micro-organisms on which antibiotics act is called the spectrum of antibiotics. On this basis there are three types of antibiotics (anti-bacterial)

(a) Narrow spectrum antibiotics

Those antibiotics that mainly affect either gram-positive or gram-receptor (Gram negative) bacteria are called narrow-spectrum antibiotics.

Example- Penicillin G.

(b) Limited Spectrum Antibiotics

Those antibiotics (bactericides) which are effective only on one organism or one disease are called limited spectrum antibiotics.

(c) Broad Spectrum (antibiotics)

Antibiotics that kill or inhibit a wide range of both gram-positive and gram-negative bacteria are called broad-spectrum antibiotics. Examples are ampicillin, amoxicillin, vancomycin, ofloxacin and chloramphenicol. Of these, ampicillin and amoxicillin are synthetic versions of penicillin. Chloramphenicol is readily absorbed in the gastrointestinal tract and can be given orally. It is beneficial in diseases like typhoid, dysentery, pneumonia, urinary infection and meningitis etc.

The antibiotic, desidazirin, is known to be toxic to certain strains of cancer cells.

(ii) Antiseptics And Disinfectants

(a) Antiseptic

Antiseptics are chemicals that kill or inhibit the growth of microorganisms. Antiseptics can be applied to living tissues such as wounds, bruises and ulcers. Examples are Furacin, Soframycin, Dettol, Bithionol, Iodoform, Boric Acid and Iodine etc.

(i) Dettol is a mixture of chlorophyllinol terpineol and pure alcohol.

(ii) Bithionol is added to soap to produce antiseptic properties.

(iii) Iodoform (CHI₃) is used as antiseptic on wounds as it decomposes to give iodine.

(iv) A dilute aqueous solution of boric acid (H₃BO₃) is a weak antiseptic for the eyes.

(v) Iodine is a strong antiseptic and 2-3% solution in its alcoholic water mixture is called tincture of iodine. It is applied on the wound.

(vi) Many organic pigments have the ability to bind to the chromatin present in the nucleus of the bacterial cell and inactivate it, thereby neutralizing the bacteria. Example- methylene blue, mercurochrome and gentian violet.

(vii) Antiseptics are also added to toothpaste, mouthwash, face powder and soap to deodorize.

(b) Germicidal (Disinfectant)

Disinfectants are chemicals that kill micro-organisms but are not safe for use on biological tissues. Therefore, they are used to disinfect inanimate objects like floors, drains and instruments etc. Example

(i) An aqueous solution of chlorine at 0.2 to 0.4ppm concentration is a disinfectant.

(ii) Sulfur dioxide (SO2) also acts as a disinfectant at very low concentrations.

(iii) Sometimes the same substance, which is primarily a disinfectant, can be used as an antiseptic by reducing its concentration. For example, a 1% solution of phenol is germicidal while its 0.2% solution can be used as an antiseptic.

Difference Between Antiseptic And Disinfectants

Antiseptic	Disinfectants
These inhibit the growth of microorganisms.	They kill micro-organisms.
They are used on living tissues.	They are used on inanimate objects.
They are used in small quantities and their effect is slow.	They are used in large quantities and their effect is intense.
They remain effective for a long time.	They are effective only for a short time.

Antifertility Drugs

The drugs which reduce the fertility of the organism are called antifertility drugs. Birth control pills contain a mixture of synthetic estrogen and progesterone derivatives. Both of these are hormones. Progesterone inhibits ovulation. Synthesized progesterone derivatives are more effective than natural progesterone. Norethindrone is a synthetic progesterone derivative primarily used in birth control pills. Ethinylestradiol (Novastrol) is an estrogen derivative used in combination with a progesterone derivative in birth control pills.

The compounds which interfere with pregnancy are called Contraceptive Substances and the chemicals which destroy the ability to produce children are called Chemostrilants.

Example- (i) M-xylohydroquinone obtained from pea oil reduces the ability to conceive in rats and it also has a significant effect on the conceiving capacity of females.

(ii) A chemical called danazol causes an effective reduction in the sperm count in men.

(iii) Aromatic hexahydroxydialdehyde called gossypol obtained from cottonseed oil is the most effective anti-fertility agent for males.