8. Mode of administration. This has a definite impact on the dose. Example: Injections may require smaller doses.
Drugs are introduced into the body by different routes, each serving a specific purpose.
Oral administration of medications is the most common method. Advantages are (1) convenience, (2) economy, (3) the drug need not be absolutely pure or sterile, and (4) a wide variety of dosage forms are available. Oral medications include tablets, capsules, liquids, and suspensions. Disadvantages include (1) inability of some patients to swallow, (2) slow absorption, and (3) partial or complete destruction by the digestive system. Other routes associated closely with oral administration are SUBLINGUAL and BUCCAL.
Parenteral medications are those introduced by injection. All drugs used by this route must be pure, sterile, pyrogen-free (pyrogens are products of the growth of microorganisms), and in a liquid state. There are several types of parenteral administration.
Inhalation is the introduction of medications through the respiratory system in the form of a gas, vapor, or powder. Inhalation is divided into three major types:
Ointments, creams, lotions, and shampoos are examples of topical preparations. Topical application serves two purposes: (1) local effect-the drug is intended to relieve itching, burning, or other skin conditions without being absorbed into the bloodstream and (2) systemic effectthe drug is absorbed through the skin into the bloodstream. Example: Nitroglycerin paste
The rectal method is preferred to the oral route when there is danger of vomiting or when the patient is unconscious, uncooperative, or mentally incapable.
Suppositories, creams, or tablets are examples of vaginal preparations which are inserted into the vagina to produce a local effect.
The definition of a drug is any chemical substance that has an effect on living tissue but