Toxicology

TOXICOLOGY

 

Photo credit: http://2fm.rte.ie/blogs/tubridy/drinkanddrugs.jpg

Toxicology primarily tackles about the adverse effects of chemicals and toxic substances to the body. An intake of a specific substance larger than its intended dose would lead to toxicity which is of high significance in toxicology. An overdose of any substance could be lethal, thus leads to poisoning. This area of science also gives us the knowledge on how to alleviate and prevent such conditions. 

THE POISON IS THE DOSE! 

 Video credit: http://www.youtube.com/watch?v=THr7roac0cA    

 

To further under understand the effect and the potential hazard that can be induced by a specific chemical, toxicologists must know what are the outcomes that it can generate and the dose that is required to produce such effect. Dose response relationship is a concept that is used in toxicology to correlate the exposures and scale of its effects induced. 

 

 

Photo credit: http://www.eoearth.org/article/Dose-response_relationship

The dose response curve typically has a sigmoid curve and the point at which toxicity first shown is recognized to be as the threshold dose level. This curve is significant in knowing the toxicity that a substance could generate at specific level of doses. 

 

Divisions of Toxicology 

a) Drug Abuse Screening – these are the drugs that are used that could bring on and stimulate addictiveness and dependence on a specific drug.    

b) Therapeutic Drug Monitoring (TDM) - this determines the dosage of a drug which can be beneficial or even detrimental to the patient involved. 

            a.) therapeutic – will make the patient well

            b.) sub-therapeutic – this has a concentration below the therapeutic range             therefore producing only low healing benefits.

            c.) toxic dosage – this will produce danger to the patient due to the over dosage    of the drug; could result to death.       

c) Emergency Toxicology - determines the level of severity and presence of drug in patients who were poisoned or had ingested large amount of drug in their body such as salicylate poisoning which is common in children.     

d) Forensic Toxicology – involves the measurement and identification of drugs used for medico-legal aspects.           

 

Routes of ENTRY of Toxic Substances

a) Ingestion – this involves the taking in of the material by mouth thus, introducing toxic chemicals to the body.

b) Inhalation –Breathing in the toxic substance will allow its entry to the lungs, having its contact to the small blood vessels present in it, thus introducing the toxic substance in the tissues.

c) Absorption – This is done usually by having the toxic substance have a contact in the skin or in the eyes. This may result to the substance’ absorption and may produce local effects.      

 

             TOXICOKINETICS AND TOXICO DYNAMICS

TOXICOKINETICS - is defined as to how the body handles the toxic substances in a human system which can be indicated by the concentration of that specific toxic at various time points. In toxicokinetics, the toxic undergoes adsorption, distribution, biotransformation and excretion/clearance in the body. 

TOXICODYNAMICS – the action of an exogenous compound (toxic substances) within an organism including the toxic’s effect on its course of action at the molecular, biochemical, and physiological level. 

  

 CHRONIC vs. ACUTE Exposure

Chronic Exposure – this involves a long term contact with the toxic chemical which can be delivered at certain frequencies. Usually, the dose that is delivered in this type of exposure is at low concentration.

Acute Exposure – this involves the immediate delivery of the dose and could result also to instant effect. The dose that its involved in this exposure is commonly in a high content concentration.  

  

Classifications of Toxic Chemicals

 Irritants – from the word itself, Irritant, upon contact with such substances will produce irritation.   

Asphyxiants – the action of this is to reduce the composition of oxygen in the tissues.

Narcotics/Anaesthetics – the main action of this is to trigger Central Nervous System depression.

Systemic Poisons – this could inflict internal damage to the body system.

                a) Hepatic Agents – induces damage to the liver

                b) Nephrotic Agents – induce damage to the Kindeys

Carcinogens – may cause cancer to humans.

Mutagens – if e person gets exposed to such substances, it could result to having undesirable mutation to occur in his/her system.

Teratogens – if a pregnant woman is exposed to this substance, the fetus will be at risk of having defects.

Sensitizers – could trigger an allergic –like type of response upon exposure to this substance.

 

The TWO most Abused substances

1) Alcohol

“It's a familiar feeling. A few too many the night before and the morning brings headaches, nausea - and the pledge that you'll never drink again. But then you do.” –Caroline Ryan, BBC News Online health staff

 Upon the intake of alcohol in the body, it could trigger the release of a certain chemical which will facilitate the release of the feeling of satisfaction in the body. The increase production of Endorphin, also known as the pain killer, also somewhat defines why the body craves for it in a way. It also affects the GABA and glutamate which specifically functions to control how the messages are sent between the nerve cells and the brain.

What does it do to our Body?   

• 1. Absorption of information restricted; memory impaired; inhibitions lowered  
• 2. Tunnel vision; difficulty in distinguishing light intensity  
• 3. Central nervous system impaired; intestinal irritation can lead to ulcers; high levels can lead to coma or death  
• 4. Change in fat metabolism, eventually leading to scarring of the liver  
• 5. Sexual performance inhibited, possibly leading to impotence  
• 6. Co-ordination and motor skills impaired; increased swaying  

(Source: Johns Hopkins University)     

 2) CIGARETTE (Tobacco)

Cigarette is a kind of a stimulant which causes its user to be in a mood of feeling good and energized.  The specific substance that it contains, which is also the stimulant itself, is called Nicotine. In moods such as depression, this initiates the feeling of having a short boost.  It also facilitates the release of beta-endorphins which causes the body to feel more alert and calm. BUT! These effects that are brought by Cigarette won’t last long in the body system.  If this substance will be repeatedly used, the body will compensate resulting to lowering of the body’s natural mood and energy level. Thus, users tend to abuse this substance so as for them to have the feeling of being normal.

Anything that  is taken excessively results to bad outcome. Studying toxicology would be a huge help in knowing and preventing the occurrence of being intoxicated by substances by means of knowing the right amount of doses. That's it and I hope that this blog gave you some understanding about what Toxicology is.♥