drug monitoring

Question 1

what investigation should you do before starting vancomycin?

Answer 1

serum creatinine. because clearance of vancomycin is reduced in patients with renal dysfunction. renal function must be taken into account when choosing the dosing regimen for vancomycin.

Question 2

what are the 2 main side effects of vancomycin?

Answer 2

nephrotoxicity, ototoxicity

can rarely cause neutropenia, would usually occur after 1 week. but neutrophil count is not routine.

Question 3

what should you check before starting a statin?

Answer 3

ALT at 3 and 12 months after starting. caution starting statin in history of liver disease, if poor liver function they have increased risk of myopathy. if ALT or AST are 3 times the normal than you should NOT give a statin.

also check CK at baseline in patients who are considered at increased risk of myopathy (rare and not usually needed)

Question 4

whats the normal range for lithium?

Answer 4

0.4-0.7. toxic effects likely after >1.5 mmol/L

check 12 hr after last dose. check weekly until stable and then every 3 months.

Question 5

what diet advise should you give somebody commencing on lithium?

Answer 5

sodium depletion is known to increase the risk of lithium toxicity so advise patient not to make diet changes which would reduce sodium.

Question 6

what is a CI to starting methotrexate?

Answer 6

abnormal LFTS. due to risk of cirrhosis.

Question 7

what should you check before starting an antipsychotic?

Answer 7

fasting blood glucose

baseline ECG if CV disease/ risk factors.

Question 8

what must you check before starting amiodarone?

Answer 8

baseline CXR must be done - due to risk of pulmonary toxicity.

also must check all of: t3, TSH, t4.

caution in hypokalaemia due to increased risk of arrhythmias.

monitor LFTS during course.

Question 9

side effects of amiodarone?

Answer 9

raised serum transaminases and acute liver dysfunction. monitor LFTS at regular intervals.

Question 10

patient on carbimazole and presents with sore throat, what do you need to check?

Answer 10

neutrophil count. need to detect bone marrow supression and thus agranulocytosis.

Question 11

what are the main side effects of ACEI?

Answer 11

hyperkalaemia
hyponatraemia
AKI
check U&E at baseline and after every dose change

Question 12

what are the main side effects of sodium valproate and what should you check before starting it?

Answer 12

associated with hepatotoxicity

measure liver function at baseline and at regular intervals.

Question 13

what and how often do you check when commencing clozapine?

Answer 13

FBC weekly for first 18 weeks.