TDM Flashcards
Discuss drug characteristics that make therapeutic drug monitoring essential.
Ensuring Drug stays in the therapeutic range
ID drug-drug interactions
establish dosing regime
ID non compliance
Identify factors that influence the absorption of an orally administered drug.
Dissociation from administered form
solubility in GI fluids
Diffusion across GI membrane
Hydrophobic (nonionized)
gastric acidity: weak acids absorbed in stomach. Weak bases in the intestines
Food and other drug status
Morphine slows motility
List factors that influence the rate of drug elimination.
Relates directly to GFR
Decrease GFR means increased plasma concentration and half life
exponential rate of loss
hepatic metabolism (liver) Renal filtration (kidneys) or both
Explain steady state oscillation
5-7 doses need to establish
peak and trough concentrations “bounce” up and down
Define drug distribution and discuss factors that influence it.
Movement of a drug between blood and tissues/organs
free fractions move from blood to interstitial fluids/intercellular space
circulation depends on lipid solubility
hydrophobic can cross membranes easily
Polar cross but don’t enter lipid compartments
Ionized diffuse at a slower rate.
volume of distribution
dose of drug/concentration of drug
hydrophobic has a large volume
ionized has a small volume
Correlate drug concentrations to pharmacokinetic and pharmacodynamic parameters.
Pharmacodynamics: Physiological response of a drug and mechanism of action.
Pharmacokenetics: Movement of drugs through the body
State specimen collection and handling requirements for therapeutic drug monitoring.
most important: timing of collection
trough: right before next dose
Peak oral: 1 hour post
Peak IV: 90 min
Peak only after steady state
No gold top
EDTA tube for immunosuppressive
Cardioactive Drugs
Digoxin: Arrythmia & CHF. Inhibits Na-K-ATPase. Biotin interferes.
Quinidine: bark extract. Oral. Liver elimination
Disopyramide: Sub for Quinidine. Renal elimination
Procainamide & N-acetylblablabla: NAPA is hepatic metabolite of procainamide
Antibiotics
Aminoglycosides: Gram - and some gram +. inhibit protein synth. Nephrotoxic and ototoxic.
Gentamicin: GNR - life threatening
Tobramycin: GNR Nephrotoxic and Ototoxic. Baseline audiology needed
Amikacin: severe blood infections.
Vancomycin: GPC and GPR. Nephro/ototoxic. redman syndrome
antieleptic drugs
Phenytoin: treats seizers. can cause in hypo/hyper doses
Depakote
Carbamazepine: sever adverse effects. last resort.
Neurontin: seizers and pain.
psychoactives
Lithium: Mood altering. Bipolar, depression. headaches/migraines
TCA: depression, amnesia, libido, apathy. Cross reactive so TDM is hard
Clozapine: schizophrenia.
immunosuppressives
cyclosporin: graft host disease.
Tacrolimus FK 506: 100x more potent than above.
sirolimus: antifungal.
Everolimus
MPA: neutral pH absorption (intenstines)
