Drugs Classification
Drugs can be further classified as:

I) Allopathic Drugs:The term "Allopathy" refers to the principle of curing a disease by administering substances that produce the opposite effect of the disease when given to a healthy human.

Allopathic drugs can be further classified as:
A) Non Prescription Drugs:Non Prescription Drugs are the drugs, which can be purchased from a pharmacy without the prescription of a doctor. These drugs are also called as Over-the-counter drugs.

1. Anti-Hemorrhoid Drugs:Anti-Haemorrhoid Drugs are medicines that reduce the swelling and relieve the discomfort of haemorrhoids. Antihemorrhoid drugs are available as creams, ointments and suppositories. Most can be bought without a physician's prescription

2. Topical Antibiotics:Topical Antibiotics are medicines applied to the skin to kill bacteria. Topical Antibiotics helps in preventing infections caused by bacteria that get into minor cuts, scrapes, and burns. Treating minor wounds with Antibiotics allows quicker healing. If the wounds are left untreated, the bacteria will multiply, causing pain, redness, swelling, itching, and oozing.

3. Cough-Suppressants:Cough Suppressants are medicines that prevent or stop coughing. Cough Suppressants act on the center in the brain that controls the cough reflex. They are meant to be used only to relieve dry, hacking coughs associated with colds and flu. They should not be used to treat coughs that bring up mucus or the chronic coughs associated with smoking, Asthma, Emphysema or other lung problems.

4. Anti-acne Drugs:Anti-acne drugs are medicines that help clear up pimples, black heads, white heads, and more severe forms of acne. Different types of anti-acne drugs are used for different purposes. For example, lotions, soaps, gels, and creams containing benzoyl peroxide or tretinoin may be used to clear up mild to moderately severe acne. Isotretinoin is prescribed only for very severe, disfiguring acne.

5. Non-steroidal Anti-inflammatory Drugs:Non-steroidal Anti-inflammatory Drugs are medicines that relieve pain, swelling, stiffness, and inflammation. Non-steroidal Anti-inflammatory Drugs (NSAIDs) are prescribed for a variety of painful conditions, including Arthritis, Bursitis, Tendinitis, Gout, sprains, strains, and other injuries. Non-steroidal Anti-inflammatory Drugs relieve pain, stiffness, swelling, and inflammation, but they do not cure the diseases or injuries responsible for these problems.

6. Antiseptics:Antiseptics are medicines that slow or stop the growth of germs and help prevent infections in minor cuts, scrapes, and burns.Antiseptics are applied to the skin to keep bacteria from getting into wounds and causing infection. Although Antiseptics do not usually kill bacteria, they do weaken them and slow their growth.

Simply applying an Antiseptic to a wound is not adequate treatment. The wound should be cleaned first and in most cases it should be covered with a bandage or other type of dressing to keep it clean and moist while it heals. However, some Antiseptics, such as Phenol, can damage the skin if the wound is covered after they are applied.

7. Analgesics:Analgesics are medicines that relieve pain. Analgesics are prescribed to relieve pain of all sorts - headaches, backaches, joint pain, sore muscles and pain that results from surgery, injury or illness.

Among the most common Analgesics are Aspirin, Choline Salicylate, Magnesium Salicylate and Sodium Salicylate. Ibuprofen, Naproxen Sodium and Ketoprofen are all in the general category known as Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). NSAIDs relieve pain and also reduce inflammation. Another common analgesic, Acetaminophen provides pain relief but does not reduce inflammation.

8. Decongestants
9. Salicylates:Salicylates are medicines that relieve pain and reduce fever. Aspirin belongs to this group of drugs. Other members of this group include Sodium Salicylate, Choline Salicylate, and Magnesium Salicylate. Aspirin is used to relieve many kinds of minor aches and pains-headaches, toothaches, muscle pain, menstrual cramps, the joint pain from arthritis, and aches associated with colds and flu. Aspirin is also known as acetylsalicylic acid.

10. Vasodilators:Vasodilators are medicines that act directly on muscles in blood vessel walls to make blood vessels widen (dilate). Vasodilators are used to treat high blood pressure (hypertension). By widening the arteries, these drugs allow blood to flow through more easily, reducing blood pressure.

11. Antacids:Antacids are medicines that neutralize stomach acid. Antacids are used to relieve acid indigestion, upset stomach, sour stomach, and heartburn. Some antacid products also contain the ingredient Simethicone to relieve gas. Antacids are taken by mouth and work by neutralizing excess stomach acid. They contain ingredients such as Aluminum Hydroxide, Calcium Carbonate, Magnesium Hydroxide, and Sodium Bicarbonate, alone or in various combinations.

12. Expectorants:Expectorants are drugs that loosen and clear mucus and phlegm from the respiratory tract. Guaifenesin is an ingredient in many cough medicines, such as anti--Tuss, Dristan Cold & Cough, Guaifed, GuaiCough, and some Robitussin products. Some products that contain guaifenesin are available only with a physician's prescription; others can be bought without a prescription. They come in several forms, including capsules, tablets, and liquids.

13. Anti-fungal Drugs:Fungi cause fungal infections. These fungi surround us and frequently land on our skin and are inhaled into our lungs. Many fungi are harmless, some cause minor and irritating infections while a few can cause much more severe infections. People with compromised immune systems, such as AIDS and cancer patients, may be more susceptible to fungal infections than others. Anti-fungal drugs are used to treat fungal infections.

14. Anti-Histamines:Antihistamines are drugs that block the action of histamine (a compound released in allergic inflammatory reactions) at the H1 receptor sites, responsible for immediate hypersensitivity reactions such as sneezing and itching. By inhibiting the activity of histamine, they can reduce capillary fragility, which produces the erythema, or redness, associated with allergic reactions. They will also reduce histamine-induced secretions, including excessive tears and salivation.

15. Antigas Agents:Antigas Agents are medicines that relieve the uncomfortable symptoms of too much gas in the stomach and intestines. They help relieve the symptoms by preventing the formation of gas pockets and breaking up gas that already is trapped in the stomach and intestines. Antigas agents are sold as capsules, liquids, and tablets (regular and chewable) and can be bought without a physician's prescription.

16. Smoking Cessation Drugs:Smoking-cessation Drugs are medicines that help people stop smoking cigarettes or using other forms of tobacco. People who smoke cigarettes or use other forms of tobacco often have a difficult time when they try to stop. Most Smoking-Cessation products contain nicotine, but the Nicotine is delivered in small, steady doses spread out over many hours. Smoking Cessation Drugs that contain Nicotine are also called Nicotine Substitution products or Nicotine Replacement therapy. These come in four forms-chewing gum, skin patch, nasal spray, and inhaler. Another type of Smoking Cessation drug, Bupropion (Zyban) also reduces craving and withdrawal symptoms, but it contains no Nicotine.

Decongestants are medicines used to relieve nasal congestion (stuffy nose). A congested or stuffy nose is a common symptom of colds and allergies. This congestion results when membranes lining the nose become swollen. Decongestants relieve the swelling by narrowing the blood vessels that supply blood to the nose. This reduces the blood supply to the swollen membranes, causing the membranes to shrink.