ABSTRACT
The term parenteral is derived from Greek words para and enteron; meaning “to avoid the intestines,” and would broadly include all routes of administration other than oral. However, in the healthcare fraternity the term is restricted for the injectable route wherein the drug is directly introduced in the body tissues, blood vessels, or body compartments. Unique advantages offered by parenteral products, as listed below, have earned them a special place in therapeutics:
1. Fast onset of drug action, due to direct introduction of parenteral product into the biological system, for critical patient care coupled with rapid termination of action offers a unique combination to the clinician
2. Highly predictable and accurate response of therapeutic agent as either all or most of the barriers preventing a drug from reaching the site of action are by-passed by the route of delivery
3. Ease of dose titration and individualized therapy based on disease state 4. Preferred route of delivery for drugs having poor permeability, high first-pass
metabolism, which are poorly absorbed by oral route 5. Allows administration of drug to unconscious and uncooperative patients
The major disadvantages offered by the parenteral route are the physical/psychological discomfort associted with injection and difficulty in self-administration. However, rapid strides are being made in the area of parenteral delivery devices, which will surmount these barriers and increase the role of parenteral delivery in therapeutics. Introduction of needleless injections and home infusion programs signal toward this emerging trend, which will gain momentum in the near future.
