Antimicrobial TDM and alcohol Flashcards
What features make a drug suitable for TDM (4)
- narrow therapeutic window
- large inter patient variability
- method to measure
- does not replace patient assessment and monitoring
purpose of vancomycin
inhibit bacterial cell wall synthesis to treat resistant GPO
What is the pharmacodynamics of vancomycin
- inoculum dependent = less effective with larger inoculum
- time dependent = more time exposed with drug has best effect
What are required for AUC/MIC of vancomycin
Draw trough within 30 minutes but peak is NOT required
What are the adjustments needed for Vancomycin troughs of:
<10mg/L
10-20 mg/L
>20 mg/L
<10 mg/L = decrease interval or increase dosing
10-20mg/L = target troughs
> 20 mg/L = increase interval or decrease dose
What is the time dependent antibiotic
vancomycin
what is the concentration dependent antibiotic
aminoglycosides
what are aminoglycosides for
GNB
what is the AUC/MIC for aminoglycosides
measure peak levels to assess efficacy - concentration dependant
measure trough to minimize toxicity - narrow therapeutic index
which adverse effect of aminoglycosides is ireversible
otoxoticity - loss of hearing and balance
What does extended interval dosing use (EID)
- uses concentration dependent killing and drug free intervals
- Uses post antibiotic effect (stunning the bug before it starts to grow again)
Which antifungal is non linear and dangerously associated with toxicity
Voriconazole
What makes voriconazole dangerous (3)
- narrow therapeutic index
- well absorbed
- high tissue distribution
Why is inter/intra patient variability high for voriconazole?
CYP2C19 - is different for patients = different metabolism rates
why are genetics for pharmacokinetics important for voriconazole
asians are poor metabolizers of voriconazole due to CYP2C19
where is alcohol absorbed the most
small intestine due to more surface area
What concentration of alcohol is best for absorption
20-30%
how long does it take for majority of alcohol to be absorbed and reach peak BAC (blood alcohol curce)
15 minutes (90% of alcohol absorbed)
30 minutes to reach peak
what is the alcohol content in high water tissues
more water in the tissue = higher alcohol content (blood and urine)
what products are made when alcohol metabolized
alcohol turns into CO2 and H2O in the liver
how does the body remove alcohol
breath, urine, sweat, tears, saliva, feces
does alcohol eliminate from the body mostly through metabolism or elimination
metabolism (90-98% of consumed alcohol)
T/F - the rate of elimination is dependent on body weight, height, age, and gender
F - rate of elimination is INDEPENDENT of those factors
What is the best body fluid to draw for testing
Urine > vitreous humor > plasma
(more water in the eye than plasma = more alcohol)
what is alcohol classified as
a CNS depressant
what are the 4 progressive effects alcohol has on the CNS and what are the BAC %
- impairment - <100mg%
- Intoxication - 100-250mg%
- Severe intoxication - 250-400mg%
- death - >400 mg%
What symptoms is seen in impairment
loss of emotion
effected driving skills - vision
what symptoms seen for intoxication
motor function loss - balance, muscle coordination, slurred speech
what symptoms seen in severe intoxication
sleep/comatosed
vomit
how does death occur with alcohol consumption
respiratory centre of brain is depressed by alcohol = stop breathing
what is the probability of causing an accident if driver is >100mg%
6x more than sober
When should specimens be collected when using the Hartford nomogram method
every 8 hours
What two methods of EID are there
- Hartford nomogram
- Trough method
what is the method of conventional dosing of AG
Multiple administrations a day to find therapeutic targets
When is sampling conducted using conventional AG monitoring
Draw levels pre and post 3rd dose
