CLINICAL CHEM EXAM 4 STUDY GUIDE 2025

A trace element, metal ion, required for optimal enzyme activity?

(metalloprotein) as a cofactor- a trace element or metal ion required for optimal enzyme activity

Odorless, tasteless white powder, lethal dose 0.12g, approved by FDA for AML.

Arsenic trioxide

Element part of the cell's antioxidant defense, involved in the metabolism of thyroid hormones.

Selenium

Element that participates in glycolysis and cholesterol metabolism.

Zinc

Tobacco smokers have 2x the amount of this element than non-smokers.

Cadmium

What helps maintain glucose, fat, and cholesterol metabolism?

Chromium

3 techniques used for elemental analysis of trace elements.

Atomic Emission Spectroscopy (AES), Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

EDTA is a chelating agent for what is found in RBCs.

calcium

The majority of absorbed lead is taken up by what?

red blood cells

Why do trace elements testing need to avoid contamination?

Elements are of low concentration in biological specimens and abundant in environment: avoid contaminating (ubiquitous) specimens from lab or collection area environments

What type of trace element GROUP are of medical interest due to their toxicity?

Non-essential trace elements

What GROUP of trace elements is needed for biochemical processes?

iron, copper, zinc, selenium, chromium, iodine, molybdenum, cobalt, and manganese

What vitamin interferes with coagulation testing (prothrombin time)?

vitamin K

Microcytic hypochromic anemia, normal iron and TIBC, basophilic stippling, what should be tested?

lead poisoning

Deficiency in what vitamin will cause abnormal bone mineralization and osteomalacia?

vitamin D

Absorption of vitamin B12 depends on the presence of what in the stomach and gut?

Intrinsic factor

What analgesic alleviates pain without loss of consciousness?

Aspirin (acetylsalicylic acid)

Biotransformation or metabolism of a drug refers to what?

The chemical process where a drug is converted into a different chemical compound within the body, usually by enzymes in the liver, transforming it into a metabolite that can be more easily eliminated from the body

What does the blood sample collection time for peak depend on?

Varies with the drug depending on its rate of absorption

Chemicals and drugs not normally found or produced in the body are known as what?

Xenobiotics

What are the common agents responsible for accidental exposure/toxicity in children?

Antifreeze

Forensic Toxicology

Concerned with medical/legal consequences of exposure to chemicals/drugs

Clinical Toxicology

The relationship between xenobiotics + disease states

Emphasize diagnostic testing + therapeutic intervention

Drug abuse testing

Environmental Toxicology

The evaluation of environmental chemical pollutants + impact on human health

Monitors occupational health issues

What drug is derived from opium poppy?

opiates and heroine

poisons

Exogenous agents that have an adverse effect on biological system

xenobiotics

Chemicals/ drugs not normally found or produced in the body; may have adverse effects on a living organism

toxins

Endogenous substances that are biologically synthesized in living cells or microorganisms

drugs

a medicine or other substance which has a physiological effect when ingested or otherwise introduced into the body.

What expresses toxicity by binding to iron in heme?

cyanide

How must the drug be to elicit a pharmacologic response?

Drugs in the free state can elicit a pharmacologic response. It is a free drug that is able to cross cell membranes and to bind at receptor sites. In the protein-bound state, drugs are unable to enter tissues and interact at receptor sites.

scurvy

vitamin C (ascorbic acid)

beri beri

thiamine (vitamin B1)

pellagra

niacin (vitamin B3)

Rickets/Osteomalacia

vitamin D

Blindness

vitamin A

Megaloblastic Anemia

folic acid

Hemorrhage

vitamin K

What is the most common amphetamine derivative?

Methylenedioxymethamphetamine referred to as "ecstasy"

What are the three most common routes of exposure to xenobiotics?

Ingestion: most often observed in a clinical setting, inhalation, and transdermal absorption

What is the most common method used as confirmatory methods for ID of DOA?

Liquid and gas chromatography

Most common agent occupational/accidental exposure/toxicity?

Pesticides

What parameters influence drug concentration and efficacy?

Age, gender, genetics, diet, prescription drugs, sled administered other the counter drugs, naturopathic agents

Evaluation of what activity is used to determine exposure to organophosphate exposure?

Serum pseudocholinesterase (SChE) activity

TDM takes into consideration what?

Route of administration, rate of absorption, distribution within the body, rate of elimination

What is substance that are added to the environment to kill unwanted life forms?

Pesticides

TDM is used for what?

Measurement of drugs and/or their metabolites in blood to maintain the highest therapeutic benefits Ensure drug dosage is within a range that produces maximal therapeutic benefit. Identify when the drug is outside the therapeutic range which may lead to drug inefficacy or toxicity

When testing a patient for alcohol should you use any type of alcohol like isopropanol to disinfect the area?

No, it can falsely elevate results

What is the most common type of alcohol poisoning?

Ethanol

When the specimen is being tested for alcohol, you must make sure that it is protected from light OR capped at all times? (Tell me which one is the correct one)

Must be capped at all times

Which drug is associated with severe hepatotoxicity?

Acetaminophen

Which vitamin B is critical component of diet of pregnant women to avoid neural tube defect in the fetus?

Folic acid (vitamin B9)

What elevates carboxyhgb?

What vitamin is not fat soluble?

ARE: A, D, E and K

Which drug administration has 100% bioavailability?

Intravenous

THC is the principle active component of what drug?

Marijuana/Cannabinoids

What has the highest affinity (LOVES) hemoglobin?

Carbon monoxide (carboxyhemoglobin)

What is the specimen of choice for cyclosporine medications?

Whole blood (lavender top)

What drugs are used to treat depression, insomnia, and loss of libido?

Tricyclic antidepressants (TCA)

Responders

patients benefiting from therapeutic + desired effects of drugs

Non-Responders:

patients NOT benefiting from therapeutic + desired effects of drugs

Rectal

suppository, most common in infants

Transdermal

absorbed through the skin

Subcutaneous

injected under the skin

Intramuscular

injected into the muscle

Effective dose

in which 50% of treated individuals will experience benefits

Intravenous

injected directly into circulation + offers the most direct and effective delivery; bioavailability of 100%

Oral

by mouth, most common route of delivery

Regulatory toxicology

uses data from mechanistic + descriptive to establishes standards regarding acceptable levels of exposure

Trough concentration

minimum concentration of a drug

Peak concentration

maximum concentration of a drug

Mechanistic toxicology

cellular + biochemical effect of toxins; context of a dose-response relationship

Descriptive toxicology

uses results of animal experiments to predict what level of exposure will cause harm to humans; risk assessment

Aerosolized

medications inhaled via a nebulizer

Clinical Toxicology

Focuses on the relationship between xenobiotics & disease states and emphasizes diagnostic testing and therapeutic intervention

What vitamin if decreased can cause spina bifida in a fetus?

Folic acid (vitamin B9)

High level of what vitamin interferes with immunoassay testing?

Biotin (vitamin B7)

What drug of abuse can cause breast reduction and testicular atrophy?

Anabolic steroids

What color top is used for trace and toxic element testing?

Royal blue top

What color top is used for immunosuppressive drugs?

Purple top: EDTA

What color top is used for the majority of TDM medications?

Red top: serum