Chapter 8 Flashcards
In which 5 groups do you have to check CK baseline before starting statins and why? What would be the threshold?
Personal or family history of muscular disorders/toxicity High alcohol intake Renal impairment Hypothyroidism Elderly
Increased risk of myopathy
Don’t start statins if >5x ULN CK
If CK raised but <5x ULN then prescribe a lower dose of statins
What is the most important thing to check before starting someone on statins? Why?
ALT/AST
Statins are metabolised by the liver, so hepatic impairment will increase their levels and thus increase the risk of myopathy
What is the threshold for ALT/AST before starting statins? When do you have to recheck?
> 3x ULN should not start statins/should discontinue
Repeat within 3 and 12 months of starting treatment
What is the half life of phenytoin?
24 hours - so one measurement is ok - peak or trough, as long as it is within the threshold - there is unlikely to be diurnal variation
When should routine serum lithium concentration be measured?
Weekly after initiation/dose change until stable
3 monthly thereafter
Additional measurements required if a patient develops disease or changes sodium or fluid intake
What are patients advised to avoid if on lithium?
Low sodium diets - sodium depletion increases risk of toxicity
Monitoring requirements: Statins
ALT/AST
CK if
- personal/family history of muscle disorders/toxicity
- elderly
- hypothyroidism
- renal impairment
- high alcohol intake
Monitoring requirements: Lithium
Serum lithium concentration
U+Es
TFTs
Monitoring requirements: Phenytoin
Plasma-phenytoin concentration
Monitoring requirements: Methotrexate
FBC, renal and liver function tests
Monitoring requirements: All antipsychotics
Prolactin
Physical health monitoring
ECG
Monitoring requirements: Olanzapine
Fasting blood glucose
Blood lipids
Weight
Monitoring requirements: Clozapine
FBC
Fasting blood glucose
Blood lipids
Weight
How long do you have to measure FBC for in clozapine? What levels do you discontinue?
Weekly for 18 weeks
Fortnightly for a year
Then monthly thereafter
Leukocytes <3000
Neutrophils <1500
Discontinue and refer to haematologist
Monitoring requirements: Amiodarone
TFTs
CXR
LFTs
serum K+
Why do you need to get a baseline CXR before commencing amiodarone?
Risk of pulmonary fibrosis (ILD)
Monitoring requirements: Digoxin
U+Es
Serum creatinine
due to digoxin being renally excreted and those with renal dysfunction are at increased risk of digoxin toxicity
In whom do you need to measure plasma digoxin concentration?
Signs of toxicity
Non-compliance
Inadequate effect
Monitoring requirements: Sodium valproate
LFTs - MOST IMPORTANT - due to hepatotoxicity
FBC
