Therapeutic Drug Monitoring and Toxicology Overview

These flashcards cover key vocabulary terms related to therapeutic drug monitoring and toxicology, essential for understanding pharmacotherapy principles.

The 3 uses for Therapeutic Drug Monitoring

1. To maximize therapeutic effect 2. To optimize its benefits to patients 3. To minimize the toxic effects of the drug

The 4 reasons for monitoring therapeutic drugs in patients

1. Patients metabolize things differently (for individual therapy) 2. To maximize therapeutic benefits while minimizing toxic effects of the drug 3. To check patient compliance with medication 4. In cases of poor correlation between dose and serum drug concentration (e.g in case the dose of the drug is not effective on the patient for therapeutic benefits due to dose being too low or anti-drug antibodies were produced)

The four processes of Pharmokinetics

1. Absorption 2. Distribution 3. Metabolism 4. Elimination

Absorption: the first process of Pharmokinetics

This is the movement of the drug from site of administration to the blood circulation

First Pass Metabolism

This is a process during absorption where the drug that is absorbed in the stomach or small intestines passes to the Liver through the portal vein before it enters into the rest of circulation

The organ that does First Pass Metabolism and metabolizes some of the drugs

The Liver in First Pass Metabolism

Distribution: the second process of Pharmokinetics

This is the process where the drug is moved from blood to tissue and it is reversible. The drug is transported by either albumin or alpha-1-acid glycoprotein

The drug that is bound to albumin or alpha-1-acid glycoprotein. Active or Inactive

Inactive drug during Distribution

The drug that is free and unbound in the body. Active or Inactive

Active Drug in the plasma

Metabolism: the third process of Pharmokinetics

This is the process where the drug is metabolized. Majority of the drugs are metabolized in the liver

The product of drug metabolism

Metabolites

Metabolites

These are products of drug metabolism, and some of them are therapeutically active. Some may be converted further in order to be excreted in the urine

Elimination: the fourth and last process of Pharmokinetics

This is the process where the therapeutic drug after it’s metabolized, it is excreted through the kidney and into the urine. Some may also be excreted through the bile or breast milk

The 5 ways that Elimination can be influenced by

1. Age 2. Health 3. Gender 4. Kidney Status 5. The patient’s Interactions with the drug

The times when Pharmokinetics are different from an average patient when it comes to Age

1. Neonates -liver and kidneys are immature 2. Prepubescent kids - have faster metabolism 3. Puberty -metabolism slows and can usually handle adult dosages if over 50 kilounits 4. Elderly Adults -Albumin decreases, kidney function has decreased

The times when Pharmokinetics are different from an average patient when it comes to Disease state

When a patient has heart, liver or kidney disease, these are the ________________.

Pregnancy and Pharmokinetics

This is another time when Pharmokinetics are different from an average patient

How we measure the effectiveness of insulin

Measure Glucose levels and HgbA1C

How we measure the effectiveness of blood pressure medication

Regular blood pressure checks

How we measure the effectiveness of Coumadin (an anticoagulant/blood thinner)

Measure INR (International normalized ratio) along with PT to look for bleeding or clotting problems or measure TP

PT

Prothrombin time; this is a test used along with INR to monitor Coudamin and to evaluate liver disease and Vitamin K deficiency

PTT

Partial Thromboplastin Time (or aPTT-Activated Partial Thromboplastin Time); This is a test to evaluate heparin therapy

The 6 Therapeutic Drug Classifications

1. Antiepileptics 2. Antibiotics 3. Antiarrythmics 4. Psychoactive Agents 5. Immunosuppressants 6. Antineoplastics

Cyclopsorine

An immunosuppressant drug commonly used to prevent organ rejection in transplant patients.

Tacrolimus

An immunosuppressant that is effective in preventing organ rejection and treating conditions like severe eczema and psoariasis.

Sirolimus

An immunosuppresant that is a drug of choice for Kidney transplant patients and is antifungal.

Psychoactive Agents

Drugs that affect a person's mental state, used in the treatment of mental health conditions.

Lithium

A mood stabilizer primarily used to treat manic depression.

Tricyclic Antidepressants

A psychoactive agent that we don’t want the patient to take too much of, for depression and apathy sinks in

Aminoglycosides

A class of antibiotics effective against infections, which can cause kidney damage and hearing loss if not monitored.

Digoxin

An antiarrhythmic medication used to treat heart failure and arrhythmias, with a narrow therapeutic window.

Antineoplastic Drugs

A suppressor of Lymphocytes (in particular T Cells). These are Chemotherapy drugs for cancer patients and drugs that are given to Kidney Transplant patients with Cyclosporine or Tacrolimus, and Patients with lupus, autoimmune disorders, and Rheumatoid Arthritis

Urinary Drug Screening

A method for detecting the presence of drugs and their metabolites in urine, commonly used for monitoring and compliance.

Chain of Custody

A legal document recorded and signed meticulously to document the handling of biological specimens to ensure integrity and prevent tampering.

Activated Charcoal

A treatment used in cases of overdose to absorb toxins and prevent further absorption.

Narcan

An opioid treatment used to reverse opioid overdoses.

Name of Psychoactive Agents Drugs (5)

1. Lithium 2. Amtriptoline 3. Clozapine 4. Olamzapine 5. Tricyclic Antidepressants

Name of Cardiovascular Drugs (3)

1. Digoxin 2. Quinidine 3. Procainimide

Name of Anti-Convulsant or Antiepileptic Drugs (8)

1. Barbiturates 2. Carbamezapine 3. Depalcote 4. Dilantin 5. Phenytoin 6.Primidone 7.Tegretol 8. Valproic Acid

Name of an Antibiotic drug group

Aminoglycoside

Names of the drugs in Aminoglycosides

1. Genamicin 2. Tobramycin 3. Amikacin 4. Vancomycin

Red Man Syndrome

A condition that occurs when a patient is given Vancomycin too rapidly; causes redness and flushing of the extremities

Two Anti-Neoplastic Drugs

1. Mycophenolic Acid (MPA) 2. Methotrexate

Methods used to look at the drug levels in a patient

1. Immunoassay (ELISA OR EIA) 2. Chromatography 3. ISE (Ion Selective Electrode) for Lithium

Half -Life

The time it takes for 50% of drug to be eliminated from the body

Steady-State

The rate of administration=the rate of elimination. This is usually reached in 5.5-7.5 half lives

Peak concentration and Trough concentration

The two different times when the sample is being drawn

Peak Concentration

The sample is being drawn when the drug concentration is at it’s highest. Usually 30 mins. after Parenteral drugs are administered and 1 hour after Oral drugs are administered

Trough Concentration

A term meaning the sample is drawn when the drug concentration is at its lowest, which is within 30 minutes before the next dosage is due. (NOTE: when drawn, we have to let others know that it was drawn and label the tube with the correct label time)

The reason we collect peak and trough samples

To make sure that the drug is in therapeutic range

Fosphenytoin is the proform of _______which is a common ___________used for seizure disorders.

Phenytoin; Antiepileptic Drug

What is the approximate number of half-life periods required for a serum drug concentration to reach 97-99% of the steady state?

5-7 half-lives

The form that the drug must be in order to elicit a pharmacologic (active) response.

Unbound free form of the drug

The serum component that is able to alter the free state of the drug level in the plasma

Albumin

Specimen requirements for lead testing

Whole blood in Tan or Royal Blue top tube with EDTA

The testing methodologies for lead testing

Mass Spectrometry and Atomic Absorption

The 3 methodologies used for Therapeutic Drug Monitoring

1. Chromatography 2. ISE (Ionic Selection Electrode) for Lithium 3. Immunoassay

The Therapeutic Drug Monitoring method most commonly used in the US

Immunoassay

Therapeutic Range

The range in which the patient achieves maximum therapeutic benefits from the drug and the least amount of toxic effects

Dosing Intervals

The time between drug doses

The difference between Therapeutic Drugs and Toxic Drugs

Therapeutic drugs are used for medicinal purposes and can be toxic when it builds up in the body. Toxic drugs are those that poison the body and are used for pleasure, to obtain a high, or to poison and kill someone and are not used for medicinal purposes.

Parenteral Drugs

Drugs that are administered through the IV or intramuscular (IM)

Transdermal drugs

Drugs that are administered through skin patches

Pulmonary Drugs

Drugs that are administered through inhalors