Drug Monitoring

Question 1

Common side effects of vancomycin

Answer 1

Ototoxicity and nephrotoxicity

Question 2

which test should be carried out before commencing long term course vancomysin

Answer 2

Creatinine - excreted renal and can cause kidney injury, so need to know baseline

Question 3

before starting a statin, what is important to check?

Answer 3

Serum ALT - caution if hx of liver disease, as they are metabolised by the liver so hepatic impairment will increase their levels and thus risk of myopathy
if active liver disease OR ALT/AST are raised 3x normal range then statin contraindicated

Creatine kinase should be checked at baseline if risk factors for myopathy

Question 4

when should serum lithium be measured, timing of sample after last dose

Answer 4

12hrs

Question 5

serum concentrations over what are likely to manifest in toxic effects, what is the normal reference range

Answer 5

1.5 mmol/l
normal: 0.4-0.8mmol/l

Question 6

What baseline checks need to be carried out before commencing lithium therapy

Answer 6

Manufacturer advises to assess renal, cardiac, and thyroid function before treatment initiation.
Body-weight or BMI, serum electrolytes, and a full blood count should also be measured before treatment initiation.
An ECG is recommended in patients with cardiovascular disease or risk factors for it.

Question 7

how often during lithium therapy do you check serum lithium

Answer 7

weekly after initiation and after each dose change until concentrations are stable, then every 3 months

Question 8

how does sodium intake effect lithium levels

Answer 8

sodium depletion is known to increase the risk of lithium toxicity and patients are advised to avoid making changes in their diet that would lead to increased/decreased sodium intake

Question 9

how often do you monitor FBC during methotrexate therapy and why

Answer 9

can cause fatal blood dyscarasis
1-2 weeks until therapy stabilised, then 2-3 months

Question 10

Contra-indication to commencing methotrexate treatment

Answer 10

liver function tests abnormal, due to risk of cirrhosis
Active infection; ascites; immunodeficiency syndromes; significant pleural effusion

Question 11

should methotrexate be reduced if significant drop in white cell or platelet count

Answer 11

No, should be stopped immediately
can be neutropenic

Question 12

how is methotrexate excreted

Answer 12

renally
toxicity more likely In the presence of renal dysfunction (bad for kidney and liver)

Question 13

what is important to record before commencing treatment with Olanzapine

Answer 13

fasting blood glucose - hyperglycaemia and diabetes can occur in patients prescribed antipsychotic drugs, particularly olanzapine. Fasting blood glucose must be tested at baseline and at regular intervals thereafter.

May do and ECG if hx of cardiovascular disease

Question 14

What is important to record throughout treatment with the combined oral contraceptive

Answer 14

BP - hypertension known to increase risk of arterial disease associated with contraceptive medication

Question 15

Requirements for baseline monitoring of amiodarone

Answer 15

T3, T4, TSH - thyroid function
baseline CXR
electrolytes - commenced with caution with those with HYPOkalaemia

Question 16

Main concern when commencing carbimazole therapy

Answer 16

neutropenia - sore throat, fever, ill etc check neutrophil count

Question 17

What should you monitor when on digoxin therapy

Answer 17

Creatinine, (U&Es)
renally excreted so need to keep an eye on renal function

Question 18

Before commencing treatment on sodium valproate, what should be monitored

Answer 18

Liver function tests - ALT, ALP, AST etc
Hepatotoxic, so liver function monitored before and during

Question 19

What should be monitored throughout clozapine treatment

Answer 19

FBC - weekly for first 18 weeks due to risk of neutropenia (then 2 weeks up to a year, then 4 weeks)
Registration with clozapine monitoring is required for all patients
Must be stopped if leukocyte count drops below 3000/MM3 or neutrophil count drops below 1500/MM3

Question 20

monitoring requirements for antipsychotics

Answer 20

FBC, U&Es, LFTs
lipids, weight
fasting blood glucose, prolactin
ECG
cardiovascular risk assesment