Exam 3 TDM/Toxicology Flashcards
Define therapeutic drug monitoring
the analysis, assessment, and evaluation of circulating concentrations of drugs in serum, plasma, or whole blood
Purpose of TDM
to ensure that a given drug dosage produces maximal therapeutic benefit and minimal toxic adverse effects
Advantages of TDM
o Identifying non-compliant patients
o Maximizing therapeutic effect
o Optimizing a dosing regimen based on drug-drug interactions
Factors that influence drug effect and dosage
Age, weight, tolerance, rate of elimination, time of administration, genetic factors, metabolism of other drugs, protein binding, disease states, medication errors/compliance
What does LADME stand for?
Liberation Absorption Distribution Metabolism Excretion
What is liberation?
The release of the drug from its dosage form
What is absorption?
Rate at which drug leaves site of administration and the extent to which this happens
What is distribution?
the process by which drug diffuses or is transferred from intravascular space to extravascular space (body tissues)
- blood flow, capillary permeability
What is metabolism/biotransformation?
o Transformation of the parent drug molecule into one or more metabolites by enzymes
What is MFO?
– hepatic mixed function oxidase
Converts hydrophobic substances into water-soluble substances
Then transported to bile or released into circulation for elimination
What is elimination/excretion?
o Rate of change of drug concentration over times varies continuously with the concentration
o Functional changes in organs can affect rate of elimination (such as hepatic disease/cirrhosis – slows clearance)
Routes of drug administration
- Injections – IV (fastest), intramuscular, subcutaneous, epidermal
- Inhalation
- Absorbed through skin (slowest)
- Rectal
- Oral
What is cytochrome P450?
- Major enzymes that metabolize drugs
* Gene group family that affects drug metabolism
What is pharmacogenomics?
the study of how a person’s unique genetic makeup (genome) influences his or her response to medications.
What is first-pass metabolism?
- Drugs administered through IV enter directly into systemic circulation
- Drugs administered orally are first exposed to the liver and may be metabolized before reaching the rest of the body
What are some routes of elimination?
- Hepatic metabolism
- Renal filtration
- Skin, lungs, mammary glands, salivary glands
What are examples of cardioactive drugs?
Digoxin, lidocaine, quinine, procainamide
What is digoxin?
- Used to treat CHF
- Draw peak levels 2 hours post dose
- Allows for better cardiac muscle contraction and rhythm
What is lidocaine used for?
Used to treat premature ventricular contractions
What is quinidine used for?
- Used to treat cardiac arrhythmias
* Prevents arrhythmias, atrial flutter, fibrillation
What is procainamide used for? How is it measured?
- Used to treat cardiac arrhythmic situations
- Affects cardiac muscle contraction
- Often measured with NAPA (N-Acetyl procainamide)
Different types of antibiotics
Aminoglycosides, vancomycin
What are aminoglycosides used for?
- Gentamicin, tobramycin, amikacin, kanamycin
• Used to treat infections with gram-negative bacteria
• Inhibits protein synthesis of the microorganism
Side effects of aminoglycodies
nephrotoxic, ototoxic
What is vancomycin used for?
- Used to treat infections with more-resistant gram-positive bacteria
- Inhibits cell wall synthesis
First generation anti epileptic drugs
phenobarbital, phenytoin (Dilantin), valproic acid (Depakane), carbamazepine (Tegretol)
Second generation. anti epileptic drugs
felbamate, gabapentin, oxcarbazepine, topiramate, etc.