Drugs are chemical substances of low molecular masses. They produce a biological response by interacting with macromolecular targets. When the biological response of these drugs is therapeutic and desirable, these chemicals are known as medicines and are used in the field of medicines that helped doctors cure many diseases and save lives to a great extent. That has successfully controlled the mortality rate and helped us to live a healthy and quality life as a boon!
Based on the chemical constituency, biological responses, and pharmacological effects, medicines are classified into various classes. Let’s discuss them in detail:
1.Antacids
In our stomach, hydrochloric acid is present that helps in digestion and also fights against stomach infection. But when this acid level increases we start feeling uneasiness, stomach ache, and in severe conditions gastric ulcers also. To cure this, we need ‘antacids’. The chemical substances which neutralize the presence of excess acids in the stomach as gastric juices and give us relief from acidity problems are known as antacids.
2. Antihistamines
Most of the allergic symptoms and diseases are cured by ‘antihistamines’. They are most commonly used by people who are allergic to pollen and other allergens. Some of the common antihistamine medicines like cetirizine, brompheniramine (Dimetapp), and Seldane, pheniramine maleate (avil), etc.
3. Tranquillizers and Analgesics
Transmission of messages from nerve to receptor is facilitated by neurologically active medicines. They are of two types: Tranquilizers and analgesics.
Tranquillizers have a relaxing effect and relieve both the physical and psychological effects of anxiety, stress, etc. and help the patients to feel relaxed and calm. The drugs are recommended for short- and medium-term use as they are a component of sleeping pills. They check the noradrenaline (neurotransmitter) level that plays an important role in mood changes. If the level of noradrenaline is low, then the person suffers from depression. To cure such problems, antidepressant medicines are required. Examples of some tranquillizers are Pentobarbital, Xanax (Alprazolam), Limbitrol (Chlordiazepoxide), Valium (Diazepam), etc.
Analgesics are medicines that help us to get rid of the pain. They are also known as pain killers. They are divided into two classes:
Non-narcotic analgesics – Antipyretics are medicines that override the secretion of prostaglandin in the hypothalamus to reduce fever by lowering body temperature. The most famous examples of this class of medicines are aspirin and paracetamol. Aspirin is chemically known as acetylsalicylic acid. It is used to reduce pain, fever, or inflammation. Paracetamol is also used to treat moderate pain, body aches, and fever. They are non-narcotic analgesics, i.e. they are non-addictive.
Narcotic Analgesics – Narcotic analgesics produce desired pharmacological effects like they reduce fever and induce sleep by interacting with specific opiate receptors. Morphine narcotics (obtained from the opium poppy) are mostly used to get relief from postoperative pain, cardiac pain, and labour pain during childbirth, severe stage of cancer, and many more.
4. Antimicrobials
Antimicrobials are a group of medicines that retards the growth of disease-causing microorganisms like bacteria, fungi, viruses, etc. For example, antibiotics are used against bacteria, antivirals against viruses, and antifungals against fungi.
5. Antibiotics
Antibiotics being less toxic for humans and animals are used as medicines to treat bacterial infections. Now, antibiotics refer to a substance produced wholly or partially by chemical synthesis which inhibits the growth or destroys the pathogens.
The development of antibiotics was started by Paul Ehrlich, a German bacteriologist, who investigated medicine arsphenamine (arsenic-based structure), well-known as salvarsan for the treatment of syphilis but they are toxic to human beings. The real revolution in the field of antibiotics was brought by the discovery of Penicillin from fungus by Alexander Fleming in 1929.
6. Antiseptics and Disinfectants
Antiseptics are the chemicals that prevent the growth or kill the microorganisms without harming the living tissues. They can be applied to wounds, cuts, and infected skin surfaces, etc. They are also used in deodorants, mouthwashes, and mouth fresheners to reduce unpleasant odours caused by bacterial decomposition in the body.
The basic difference between antiseptics and disinfectants is that an antiseptic is applied to the living cells, while disinfectants are applied to non-living surfaces to kill germs. A commonly used antiseptic is Dettol; it is a mixture of chloroxylenol and terpineol. Chlorine and phenol solutions are known as disinfectants.
Source:https://www.embibe.com/exams/chemicals-in-medicines/
