TDM/Toxicology Flashcard

Pharmacology
study of how drugs interact with living organisms and how the body affects the drugs.
Pharmaceuticals
substances that have medicinal properties.
Pharmacokinetics (PK)
the study of the body’s effects on the drug, to include; absorption, distribution, metabolism, and excretion
Pharmacodynamics (PD)
the study of the physiological effects of the drugs on the body.
Therapeutic Range
range of serum drug concentrations associated with therapeutic effect.
Trough
lowest drug concentration during a dosing interval, occurs immediately before the next dose.
Peak
highest serum concetration of a drug. Exact peak cannot be determined without frequen serial blood sampling.
Half-Life
time required for serum drug concentration to decrease by 50%
Steady State
equilibrium when the drug input equals drug excretion.
Minimum Effective Concentration (MEC)
minimum serum drug concentration needed to produce desired therapeutic effect.
Minimum Toxic Concentration (MTC)
minimum serum drug concentration needed to produce a toxic effect on the body.
Describe an optimal dosing cycle
trough blood concentration does not fall below MEC, Peak does not rise above MTC.
administered once every half life
Acheives steady state
Blood concentrations greater than MTC
place the patient at risk for the toxic effects of the drug
Blood concentrations lower than MEC
place the patient at risk for the disorder the drug was intended to treat.
Bioavailability
fraction of the drug that is absorbed into systemic circulation.

oral drugs most have greater tahn 70% of the administered use availble to the body.

First PAss Effect & Liver Biontrasformation
drugs pass through the stomach into the small intestine and directly to the liver where it is extensively metabolized before reaching the systemic circulation. Drugs are generally convered to polar, water soluble molecules through oxidation reduction or hydrolysis making them more readily excreted.
LIVER
Principal organ for drug metabolism.
Rate of absorption
usually much greater than rate of elimation. ORal drugs are formulated with larger doses because of First Pass. IV drugs MUCH smaller doses because 100% enters the blood stream.
Conditions that Influence rate of drug absorbtion
Abnormal GI motility, disease or infection of the GI tract, Food (presence or absence) and co-administered drugs.
Synergistic
drug that enhances the therapeutic effect of another drug, beneficial or harmful.
Antagonistic
drug that diminishes the action of another drug, may be beneficial ro harmful
free faction of a drug
the form capable of generating a therapeutic effect.
Liphilic drugs
cross the cellular membrane
warer-soluble drugs
interact withd rug receptors to elicit a biological response.
REnal pathway
major exretion route for water soulble drugs or drug metabolites. disease or injury of the kidnesy may geratly reduce excretion rate and half life of a drug.
Cardioactive Drugs
used to treat heart conditions, some require TDM because of a small therapeutic range.
Digoxin
cardiac glycoside used to treat cardiac arrhythmia.
Cardioactive drug.
Lidocaine, Quinidine, PRocainamide
used to correct ventricular arrhythmia and prevent ventricular fibrillation.
Cardioactive drug.
Antibiotics
effective against a wide range of bacteria.
Aminoglycosides
used for the treatment of infections with gram-negative bacter, resustant to less toxic antibiotic. I.E. gentamicin, tobramycin, amikacin, and kanamycin.
Vancomycin
glycopeptide antibiotic, effective against select gram-positive bacteriai. adminsiterd by IV infusion.
Antiepileptic
effective against epilepsy
phenobarbital
slow acting barbituate controls several types of seizures, abosprion is very slow. Antiepileptic.
Phenytoin (dilantin)
treats a variety of seizure disorders, short term prophylactic agent to produce loss of function tissue. amdin oral. Antiepileptic.
Valproic Acid
anticonvulsant and mood-stabilizing antiepileptic. USed to treat epeilepsy and bipolar disorder.
Psychoactive
drugs effective at affecting the mind or behavior.
Lithium
Orally administered psychoactive drug, used to treat manic-depressive illness, absorption is complete and rapid.
Tricyclic Antidepressants
used to treat dpression, insomina, and extreme apathy. Psychoactive drugs.
Bronchodilators
effective at dilating or expanding the air passages of the lung.
Theophylline
aersol administered bronchodilator used in the treatment of asthma or other COPDs
Advantages of having a TDM program
Detection of non-comliance, detects patients undergoing changes in drug disposition characteristics, can be used to adjust therapeutic regimens, establishes a dosage baseline.
Collection Procedure for legal toxicology exams.
Must have a Chain of Custody. Collection and preservation IAW local SOP, PRoperly label and seal container, sign and date appropriate chain of custody form.
Transportation and Storage of Legal Toxicology samples
specimens and other evidence must remain in custody of appropriate personnel or in a locked container to avoid legal obligations, decomentation includes detailed descreption of collection contatiner and signatures of transporting and receiving individuals.
Chemical Analysis of a Legal Toxicology sample
ran in duplicate alongside known controls, annoted with testing individual’s signature, stored in locked freezer per local SOP.
Reporting Results for legal Toxicology samples
Legal toxicology results are NEVER give over the phone, the only individual authorized to receive toxicology results is the registrar from patient admin.
Toxicology
science of poisons and their effects on the body
Posion
chemical agent that when ingested, injected, inhaled, or absorbed can cause tissue injury or death.
Dose
the amount of chemical agent introduced into the body.
Lethal Dose 50
Quantity of a substance required to cause death in 50% of the sample group.
Therapeutic Dose
amount of a substance that will produce a desired pharmacological effect.
Drug of Abuse
drug used in excess or for non therapeutic reasons. high abuse potential and users can become addicted.
Drug Addiction
physiological degree of drug dependence. USers are compulsively seeking, regardless of the potentiall negative consequences.
Mechanisms of Toxicity
intereferecne with critical enzyme actions, blockage of O2, interferes with cell function, hypersensitivity reactions.
Factors of Toxicity
Nature of toxicant, route of exposure, dosage, drug interactions, biological variables.
Clinical Toxicology
Analysis of drugs, heavy metals and other chemical agents to support patient care.
Forensic Toxicology
effects of potentially toxic substances as a determination of a cause of death to aid in medico-legal investigations.
Examples of Psychostimulants
cocaine, amphetamines, methamphetamine, MDMA
Examples of Cannabinoids
Marijuana, hasish
CNS depressants
barbituarates alcohol, benzodiazepines
Exampels of Opioids
morphine, codeine, oxycodone, oxymorpone, heroid, opium
Psychedelics
LSD, designer amphetamines, peyote, [silocybin, PCP
Examples of Sports enhancing drugs
anabolic steroids, hGH
Examples of General Stimulants
nicotine, tobacco, caffeine
Examples of inahalants and anestehtics
volatile nitrites, organic solvents.
Medico-legal cases
possibility of criminal poisoning exists, legal action may be taken to determine liability.
Chain of Custody
unbroken documentation trail of accountability, guarantees a samples security, inclusdes whi came in contact with a sample, why, and where it occurred.
Ethanol
the most common drug of abuse seen in the emergency room.
SOurces of ethanol
fermentation, distillation
Major uses of alcohol
alcoholic beverages, solvents, antidote for methanol poisoning.
Legal issues resulting from Alcohol
BAC of greater that .08% legal evidence for a criminal conviction for intoxicated driving.
any detectable ethanol present whil on duty is grounds for UCMJ
Metabolism of Ethanol
rapidly absorbed from the GI tract, 20% is absorbed from stomach, 80% from the samll intestitime. 90-98% is oxidized to acetaldehyde by alcohol dehydrogenaze.
Effects of alcohol on the musclar system
coordination is impaired.
Efects on the circulatory system of alcohol
blood vessels dialate causing heat loss.
effects on the respiratory system of alcohol
small doses stimulate respiration
effects of the nervous system of alchol
low doses causes lowered social inhibition, followed by mental confusion and uncontrolled mood swings, excessive doses cause loss of consciousness or coma.
effects of alcohol on the digestive system
increase in secretions cause stomach irritation, chronic use causes hepatatis and cirrhosis.
effects of alcohol on the reprodcutive system
women : misscarriage, infant death, Fetal Alcohol Syndrome.
Males : impotence and decreased testoterone.
Treatment for alcoholism.
Withrdol from alcohol is more severe and more likely to cause death than ANY OTHER DRUG.
Detoxification, clear stomach and treat DT with denzodiazepine.
Acetiminophen
over the counter anagelisc, large amoutn of cytochrome p450 causes liver damage. REnal damage less frequently. alcoholics more prone to posisonig.
Carbon Monoxide
most commonly encountered tpoxic cause. toxicity is consequence of cellular hypoxia.
LEad
toxic to multiple oragn systems, inactivation of enzymes and other macromolecules.
MErcury
itoxic to the CNS ptoent tertogen, mecuric salts are corrosive to skin eyes and GI tract, nephrotoxic.
ORganophosphates
inhibit the critical enzyme acetlchoinestrase. found in insectisides and chemical warfare agents.

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