Table of Contents
Nature and sources of drugs
Drugs
A drug is a chemical substance, typically of known structure which administered to living organism produce a biological effect.
A pharmaceutical drug also called a medication or medicine. It is a chemical substance used to treat, cure prevent or diagnose a disease or to promote will being
Nature of drugs
Mostly drugs are normally solids like paracetamol and ampicillin but some such as ethanol, glycerol are liquids and few like nitrous oxide are gaseous. The molecular weight of majority of drugs in the range of 100-1000D.
According to their action
1. Preventive drug
Those drugs which is used to prevent the causes of the disease. Preventive drugs are medications that are taken on a regular basis in order to prevent the onset of a certain illness or condition. They can be used to reduce the risk of heart disease, stroke, and other chronic illnesses, as well as to reduce the risk of certain types of cancer.
Additionally, they may be used to treat conditions such as high blood pressure and diabetes. By taking preventive drugs regularly, individuals can help ensure that they stay healthy and avoid serious medical issues down the road.
2. Symptomatic drug
Those drugs which is used to tests the symptom of that disease or condition, rather than the underlying cause. These drugs can provide relief from symptoms such as pain, fever, and inflammation, allowing patients to live more comfortably while their underlying condition is treated.
Symptomatic drugs can also be used to prevent further progression of a disease or condition. While symptomatic drugs do not cure the underlying cause of a disease or condition, they can provide relief and improve quality of life for those suffering from it.
3. Diagnostic drug
Those drugs which help to determine the reason or causes of any disease. Diagnostic drugs are a type of medication used to diagnose and treat medical conditions. They help doctors to determine the cause of a patient’s symptoms and provide information about the severity of the condition.
Diagnostic drugs are used in conjunction with other treatments, such as surgery or radiation therapy, to ensure that the most effective treatment is chosen. In addition, diagnostic drugs can be used to monitor a patient’s progress and determine if any changes need to be made in their treatment plan.
4. Curative drug
Those drugs which is used in treatment of any disease. Curative drugs are medications designed to treat a disease or condition and restore health. These drugs aim to cure the underlying cause of the disease, rather than just alleviating the symptoms. Curative drugs are often used in combination with other treatments such as lifestyle changes, surgery or radiation therapy.
5. Contraceptive drug
Those drugs are playing an important role in preventing unwanted pregnancies, reducing the spread of sexually transmitted diseases, and allowing individuals to make informed decisions about their sexual lives. Contraceptive drugs can come in many forms, including pills, patches, injections, and implants.
6. Health maintenance drug
Those drugs which help to maintain our health.
Sources of drugs
1. Plants
Plant-based drugs have been an important source of medicines for centuries. Plants are a rich source of natural compounds that can be used to treat a wide range of ailments.
2. Animals
Drugs derived from animals are becoming increasingly popular as a source of medical treatments. Animals, such as bees and reptiles, have been found to produce a variety of compounds which can be used to treat various conditions. These drugs are often referred to as “natural” or “traditional” medicines, as they are derived directly from the animal sources.
3. Microbes
Mostly antibiotics are obtained from fungi and bacteria. Sometimes vaccines are also produced by the uses of microbes.
4. Minerals
Drug sources from minerals have been used for centuries in medical treatments and therapies. There are many more minerals which is used as medicinal substances, like iron and zinc. Minerals can be found naturally in the environment, or they can be extracted from rocks and soils. These minerals are then processed into drugs that are used to treat a variety of ailments.
5. Synthetic
It is the largest surfaces of medicines. It has the advantage of purity and uniformity of the product, they can be manufactured as per need, like fluoroquinolones and paracetamol.
6. Biotechnology
Biotechnology has become an integral part of drug development and production. It provides a wide range of sources for the production of drugs, ranging from natural sources to the use of genetic engineering. This technology has enabled us to develop new drugs more quickly and efficiently, with fewer side effects. By understanding the different sources available for drug production, we can better understand how biotechnology is used in drug development and production.
Essential drug consent
WHO (World Health Organization) introduced the concept of essential medicines (drug) in 1977. These are those drugs which satisfy the priority health care needs of the population.
Criteria

The are selected with due regard to-
1. Public health relevance.
2. Clinical evidence on efficacy and safety.
3. Comparative cost effective (individual & community can afford).
4. Available at all time in adiate amount.
5. Appropriate dosage form.
6. Assured quality and adiate information.
India proposed its first list in 1996, and has revised it in 2011, and now in April 2015 with the title name “National list of essential medicines”. The WHO updates the list in every two years. It can be differed from country to country due to change their environment. Example:- Acetylsalicylic acid, Paracetamol, Ibuprofen, morphine for pain and palliative care.