drug action and monitoring Flashcards Preview

2D week 1 - stroke > drug action and monitoring > Flashcards

Flashcards in drug action and monitoring Deck (15)
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1
Q

what is pharmacokinetics

A

how the body handles drugs; affected by clearance rates and plasma conc

2
Q

what is pharmacodynamics

A

the action of the drug on the body; affected by ion channels, enzymes, peak flow, BP; monitored using blood tests (CRP, LFT)

3
Q

why do drugs need to be monitored?

A

no one responds in the same way and so decisions on prescribing need to be guided by monitoring

4
Q

what is the aim of drug monitoring

A

maximise benefit and minimise harm

5
Q

how should the effect of a drug be measured (6)

A

symptoms; signs; clinical measurement; lab/radiological markers; directly sample drug conc; combination of methods - don’t rely on a single measure!

6
Q

examples of clinical measurements (4)

A

heart rate (w Beta blockers); BP (with CaCh blockers); resolution of ankle oedema (w furosemide); peak flow (with salbutamol)

7
Q

what to look for if the patient is experiencing recurrent blackouts?

A

tachy/bradycardia

8
Q

what to look for if the patient is experiencing fluid overload?

A

check body weight to see if fluid is being removed; check U&Es for renal toxicity

9
Q

what to look for if the patient is experiencing heart failure?

A

creatine levels; K+ levels after starting ACE inhibitors

10
Q

what are the problems with using plasma conc for therapeutic drug monitoring?

A

venous level may not equal conc at target (e.g. bc has to pass throught BBB); is there a correlation with clinical effect?; doesn’t account for metabolites; there is heterogeneity in the population

11
Q

why would plasma conc be checked

A

good correlation between drug level and response/toxicity; good indication for a test

12
Q

what drugs is TDM mainly used for? (6)

A

antibiotics; digoxin; antiepileptic; lithium; aminophylline; immunosuppressants e.g. ciclosporin

13
Q

gentamicin standard dose

A

5-7mg/kg/24hrs; high trough levels may result in renal toxicity

14
Q

vancomycin dosing procedure

A
  1. loading does + saline
    2.12hrly infusion if eGFR >40ml/min
  2. trough blood sample
  3. adjust dose accordingly
15
Q

digoxin toxicity (3)

A

nausea; disturbed colour vision; unexplained ECG changes