Clinical Chemistry Blog Notes 8F: July 2012

We are surrounded by a lot of chemical substances that can provide ease from pain and illnesses but can also produce toxic effects if more than the desired amounts enter our bodies. Doctors, when we are sick, prescribe a lot of medicinal drugs that could have adverse effects. A lot of people also take over-the-counter drugs even without medical supervision. Other people consume large amounts of alcohol and cigarettes in their social lives and some become addicted. Alcohol is the most commonly abused substances in the United States, and possibly the entire world.

What is Toxicology?

Toxicology deals with the study of the antagonistic effects of chemicals on living organisms. It is concerned with the study of symptoms and treatments and categorization of poison.

Different types of Toxicology:

Descriptive Toxicology - toxicity testing of chemical substances to provide information for safety evaluation.
Mechanistic Toxicology - identification and understanding chemical, biochemical and molecular basis by which toxicants have effects.

Regulatory Toxicology - based on mechanistic and descriptive studies, set standards for safety exposures.
Developmental Toxicology - concerned with the life-long antagonistic effects of toxicants (before conception, during prenatal development and postnatal).
Forensic Toxicology - measure toxins and drugs in tissues for medico-legal aspects (example: to determine the cause of death of a person)
Occupational Toxicology - concerned with the hazards occurring in workplace and preventing antagonistic effects in employees.
Environmental Toxicology - is the study of the nature, effects and detection of toxic substances in the environment.
Clinical Toxicology - concerned with diseases, diagnosis and treatment of poisoning.

Routes of Exposure

Exposure through inhalation, skin contact and ingestion provides opportunity of obtaining a poisonous dose.
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Drug Abuse Screening

- To monitor usage of a drug for a nontherapeutic effect, to detect and evaluate a drug overdose, and to monitor someone with a substance abuse problem. Some of the most commonly abused drugs are:

§ Alcohol (Ethanol, grain alcohol)

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§ Nicotine (main addictive agent in cigarettes)

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§ Cocaine (coke, snow, white lady, crack)

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§ Caffeine (coffee)

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Therapeutic drug monitoring

- Measurement of serum concentrations that enables the physician to correct and adjust the dose.

§ Toxic dose – higher than the required dose, produces toxic effects

§ Therapeutic dosage - required dose to produce the desired effect

§ Subtherapeutic dose – less than the required dose

Toxicology is essential because it helps us understand the harmful effect of drugs and other chemical substances. It also helps in improving the health of humans, animals and the environment.