Classification of Drugs

Drugs:

Drug is any substance presented for treating, curing or preventing diseases in human beings or animals. It may also be used for making a medical diagnosis or for restoring, correcting or modifying physiological functions.
A drug is a substance which may have medicinal, intoxicating, performance enhancing or other effects when taken to the body.

Example; penicillin, Paracetamol etc.

Classification of Drug:

Drugs may be classified according to
                                    -the origin of drugs
                                    -medicinal uses of drugs
                                    -different types of diseases.

According to the origin of Drugs:

According to the origin, Drugs may be classified into three groups.
They are-

1. Natural Compounds
2. Synthetic Compounds
3. Semi-Synthetic Compounds

Natural Compounds: 

Materials obtained from both plant and animal fall in this category.

Example: Vitamins, Hormones, Amino acids, Antibiotics, Alkaloids, Glycosides etc.

Synthetic Compounds:

They are either pure synthetic or synthesized naturally occurring compounds to reduce cost.

Example: Morphine, Atropine, Steroids, Cocaine.

Semi-Synthetic Compounds: 

Some compounds either can't ce purely synthesized or can't be isolated from natural sources in low cost. Therefore, the natural intermediate of such drugs could be used for the synthesis of a desired product.

Example: Semi-Synthetic Penicillins.

According to the Medicinal Uses of Drugs:

According to the medicinal uses, drugs are divided into two divisions-

1. Pharmacodynamic agent
2. Chemotherapeutic agent

Pharmacodynamic agent:

Drugs that act on the various physiological functions of the body are called pharmacodynamic agents.

Example: General anaesthetic, Hypnotic sedatives, Analgesics etc.

Chemotherapeutic agent: 

Those drugs which are used to fight pathogen, are classified as chemotherapeutic agent.

Example: All antibiotics, Sulphonamides, Antimalarial agents, Anti viral agents, Anti cancer agents etc. 

According to the different types of disease: 

According to the different types of diseases, Drugs are classified into three groups. 

They are-

1. Infectious Diseases
2. Non-infectious diseases
3. Non-diseases

Infectious diseases:

Born (transmitted) from person to person by outside agents, bacteria (Pneumonia, Salmonella), viruses (common cold, AIDS), fungi (thrush, athletes foat), parasites (malaria).

Example: Antibacterial, antiviral or antifungal drugs.

Non-infectious diseases: 

Disorders of the human body caused by genetic malfunction, environmental factors, stress, old age etc. are non-infectious diseases.

Example: Drugs used against diabetes, heart disease, cancer, haemophilia, asthma, mental illness, stomach ulcers, arthritis etc.

Non-diseases:

Alleviation of pain, prevention of pregnancy, anesthesia etc are non-disease.

Example: Analgesics, contraception, anesthetics etc.