A drug or medicine is any substance or mixture of substances which is taken into the body for the purpose of improving one’s physical or mental condition. In the past, medicines were usually mixtures of many plants and mineral substances, prescribed in Latin by physicians and made up by pharmacists into elixirs, powders or ointments that were often strange smelling and tasting. Today we live in an entirely different era of drugs and medicines.
Rarely are prescriptions written in Latin and reraly does the pharmacist himself prepare the drugs. Instead, most medicines are manufactured in large quantities in the form of tablets, capsules, timereleased particles, creams, suppositories and liquids for oral use or injection. Production, distribution and availability of each type of drug is controlled by legislation dating back to the first half of this century, although new laws continue to be made.
Nowadays, before a drug is introduced on the market, it must meet stringent standards of safety and effectiveness, since it may be used by millions. To determine whether it does meet these requirements, it is first tested in many animals and later in human volunteers and persons with specific diseases which the drug is designed to treat.
All drugs can be grouped according to the action they possess. The main groups are:
Antiseptic and disinfectantskill bacteria by poisoning them.
Expectorantsare used for assisting in coughing by reducing the irritation of throat.
Cough mixtures areused to suppress coughing.
Laxativesmake the bowels move.
Analgesicssoothe or relieve pain.
Tonicsare taken to strengthen the body and immune system.
Applicationfor skin and mucous membrane includes ointments, lotions, and liniments.
The drugs can be classified according to their form. The main groups are:
Pillis a small ball or tablet of medicine for swallowing whole.
Tabletis a small shaped piece of compressed medicine.
Ointmentis a semi-solid medicinal preparation made from oil or fat and usedon the skin.
Tinctureis alcoholic or hydroalcoholic solution.
To add that list we can’t but mention decoctions, solutions, infusions, powders,and suppositories.
The major characteristics of drugs are:
1. Therapeutic effect is a selective action on an organ.
2. Side effects are an undesirable action (nausea, vomiting, and rash, etc).
3. Allergic reaction is an expected individual reaction.
To these we can add indication, shelf life, and storage condition.
Drugs are most commonly can be administered in a number of ways:
• Orally, as a liquid or solid, that is absorbed through the stomach.
• Inhaled, (breathed into the lungs), as a vapour.