Drug Monitoring Flashcards
What do you test before starting biologic drugs
CXR- TB
Bloods - hepatitis B, hepatitis C, and HIV.
At what ALT factor (ie X2 or X3 or X4) are statins contraindicated and wehn do u check this?
before 3 months and 12 months
3x
when do you measure teico, vanco, gent and lithium levels?
Lithium: The goal is to monitor the steady-state concentration at its lowest point (trough), which occurs 12 hours after the dose. Monitoring earlier may not reflect true steady-state levels due to distribution phases. weekly till stable.
Vancomycin: The trough level (lowest concentration just before the next dose) is important because it ensures enough drug is present to cover the infection while minimizing the risk of toxicity. The longer monitoring window reflects the pharmacokinetics of the drug and when the steady-state trough is most accurately measured.
Gentamicin: Both peak (to ensure bacterial killing) and trough (to avoid toxicity) levels are monitored. Peak is typically measured soon after the dose (1hr), and trough (18-24hr) is measured just before the next dose.
Teicoplanin: Due to its long half-life, less frequent monitoring is needed, and it primarily focuses on ensuring effective trough levels after the 3rd-5th dose.
if pre dose (trough) levels of gent are high what do you do?
increase interval
if post dose (peak) levels of gent are high waht do you do?
decrease dose
Which two drugs have a really long half life- so much so that when you stop the drug, they continue to have effect on the body? and you may see side effects even a year later?
- Hydroxychloroquine- even following discontinuation of the offending drug may progress for over a year as it is caused by build up of hydroxychlororquine in the retina.
- Similar to amiodarone in the sense that even when you discontinue this the effects may still be seen as it has such a long half life
LFT monitoring for terbenifine
Perform baseline LFT.
Monitor hepatic function before treatment, and then periodically after 4 to 6 weeks’ of treatment.
Discontinue if abnormalities in LFTs.
Advise the patient to stop terbinafine and seek prompt medical assessment if they develop symptoms of liver injury (e.g. flu-like illness, gastrointestinal symptoms, pruritus, and jaundice), infection (e.g. fever, sore throat), or mouth ulcers
statins are continued at 3 months if…
reduction in non HDL cholesterol by 40% at 3 months
What do you monitor and how often do you monitor for statin therapy ?
what dont you monitor!
- LFTs- classic- liver injury - dont give if >3X ULN. Do LFT again at 3 months with HbA1C.
- CK- classic- myopathy, only take if muscle aches before starting therapy or during therapy - repeat after
7 days if 5x elevated. if concentrations are still raised but less than 5x ULN, the statin should be started at a lower dose - one full lipid profile, TFT and U+E before starting
- Fasting BG or HbA1c before starting and at 3 months = High-risk diabetes candidates because it can increase the risk of diabetes.
remember it has to be a high intensity statin- ATORVOSTATIN IS FIRST LINE and if non LDH level doesnt decrease by 40% you must increase statin dose or add ezetimibe.
The lipid target is low-density lipoprotein (LDL) cholesterol levels of 2.0 mmol/L or less or non-HDL cholesterol levels of 2.6 mmol/L or less.
How often do you measure HbA1c in someone who is pre diabetic?
annually
methotrexate monitoring and why
pre testing
NO CXR needed
pregnancy test
fbc - pancytopenia
ue - predominantely renally excreted. cant get rid of it and can become toxic
lft - toxic
in view of dyscrasia, liver cirrhosis and toxicity risk.
FBC UE LFT weekly until stabilised (like lithium is) then 3 monthly
be advised to report all symptoms and signs suggestive of infection, especially sore throat
lithium monitoring and why?
pre testing
BMI, FBC, U+E incl. calcium and TFT
monitoring
lithium levels- weekly, when concentrations are stable, every 3 months for the first year, and every 6 months thereafter.
BMI, FBC, U+E incl. calcium and TFT 6 monthly
why?
Leukocytosis
Insomnia
Thirst, tremor
Hypothyroidism
Increased Urination
Muscle weakness, and malaise
antipsychotics monitoring and why?
Blood glucose, lipid profile, weight and prolactin.
diabetes, metabolic syndrome including fatty liver. risk highest in first 3 months to 1 year.
Risk highest for olanzapine.
pre treatment
lipids, weight, fasting BG, prolactin
monitoring
lipids, weight for first 3 months then yearly with antipsychotic drugs. Fasting BG and prolactin at 6 months. Prolactin yearly thereafter
Patients taking olanzapine (or clozapine) require more frequent monitoring of lipids and weight: every 3 months for the first year, then yearly. Fasting BG after 1 month!!! then every 6 months. Prolactin at 6 months. Prolactin yearly thereafter.
which drugs have monitoring weekly until stable then every 3 months for first year?
- lithium
- methotrexate
- (olanzapine) not weekly just 3 monthly
- azathiopurine
- clozapine (weekly for first 18 weeks, then 2 weekly for first year)
What is monitored for clozapine?
FBC weekly for first 18 weeks, then 2 weekly for a year, monthly for second year.
Patients taking olanzapine (or clozapine) require more frequent monitoring of lipids and weight: every 3 months for the first year, then yearly. Fasting BG after 1 month!!! then every 6 months. Prolactin at 6 months. Prolactin yearly thereafter.
