Pharmacokinetics

Pharmacokinetics is derived from two words: Pharmaconmeaning drug and kinesis meaning movement.

Drug dosage form

Drugs can be administered to a patient in various forms. They are available in solid, semisolid and liquid dosage forms.

Drug distribution

Distribution is defined as the reversible transfer of drugs between body fluid compartments. After absorption, a drug enters the systemic circulation and is distributed in the body fluids.

Bioavailability of drugs (Distribution)

It is the fraction of a drug that reaches the systemic circulation from a given dose. The intravenous route of drug administration gives 100% bioavailability, as it directly enters the circulation.

Sources of drugs

They are natural, semisynthetic, and synthetic. Natural resources are plants, animals, minerals, microorganisms, etc. Semisynthetic drugs are obtained from natural sources and are chemically modified later. Synthetic drugs are produced artificially. The different sources of drugs are:

Route of Drug Administration

Local Routes:
It is the simplest mode of administration of a drug at the site where the desired action is required.
Systemic side effects are minimal.

Nomenclature of Drugs

Chemical name: It denotes the chemical structure of the drug, e.g. acetylsalicylic acid is the chemical name of aspirin and N-acetyl-p-aminophenol for paracetamol. It is not suitable for use in a prescription.