Toxicology: Introduction

Image credit: http://www.nscb.gov.ph/secstat/d_safety.asp

This table is concerned about the number of drug raids conducted with the number of people arrested due to drug-related violations. Drug addiction in the Philippines has been alarming for its increasing rates. Mostly, young people are the ones involved of the said problem. The Philippine government implemented laws to solve the current dilemma, however, because of illegal production; it becomes difficult for them to take hold of it.

Paracelsus (1493-1541) stated that “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy.” Toxicology is defined as a branch of science that deals with poisons and their harmful effect in the human body. It is the study of how natural or man-made substances can cause unwanted effects in a living individual.

To further more understand the meaning of toxicology, some important terms are included.

• Toxic – it is a term relating to a poisonous material that is capable of causing deadly effects by exposure with a chemical.

            Routes of exposure involved are via inhalation, ingestion, absorption, or by a skin or direct contact.

• Toxicity – It describes the degree to which a certain substance can be poisonous or can cause injury. It usually depends on different factors: dose, route of exposure, duration, shape or structure of the drug and some individual human factors.
• Selective toxicity – it means that a substance will produce an injury to a one kind of organism without harming another, though both may exist together.

Drug mechanism

This figures show the interplay between the absorption,

 distribution, metabolism and excretion of a drug.

Image credit: 

http://pharmaxchange.info/press/2011/04/pharmacokinetics-basics-absorption-distribution-metabolism-and-excretion/

Absorption

Absorption takes place when a toxin (naturally derived) or a toxicant (man-made toxic chemical) was able to cross cell membrane. Before a compound is able to reach a tissue, it is usually taken in the bloodstream.

Storage

Substances are stored on the following tissues: adipose tissues, bones (chemicals that are similar to calcium), blood, liver and kidney, etc.

Distribution

The substances are released from storage. Distribution determines the concentration of a drug in a particular tissue. A drug is usually subjected to various distribution processes to lower its plasma content.

Metabolism

As soon as they enter to the body, the compounds break down. As metabolism takes place, the initial compound is to be converted to other new compounds (metabolites) and usually reduces its effect in the body.

Excretion

Through kidneys, compounds and their metabolites are needed to be removed in the body. Until excretion is complete, the accumulation of foreign substances can cause adverse effects in the body’s normal metabolism. The three sites where drug excretion occurs are kidneys (through urine), fecal or biliary excretion (through waste products or feces), and lungs.

Sub-disciplines of Toxicology

Sub-discipline	Concern
Environmental Toxicology	Study of chemicals which contaminate food, water, soil, or atmosphere. How a variety of plants, animal, and humans are affected by the exposure to toxic substances
Industrial Toxicology	Cornered of the effects (usually health effects) from the exposure of the workers to the chemicals in their workplace.
Food Toxicology	It is involved in the delivery of edible and safe supply of food to the people. The additives are studied to determine at what amount they may generate adverse effects.
Clinical Toxicology	Concerned with the diseases associated with exposure to toxic substances.
Forensic Toxicology	It is used to determine lethal effects that result from the exposure to toxic substances. It is used to establish the cause and effect relationship between exposures to a drug

To furthermore understand Toxicology, please watch this video.

Video credit: http://www.youtube.com/watch?v=7lCQ96LKOyM

Thanks for reading! Please look forward to my next post :)