Statins Flashcards
What is the mechanism of action of statins?
Inhibit the action of HMG-CoA reductase, the rate limiting enzyme in hepatic cholesterol synthesis
What are 3 key adverse effects of statins?
- Myopathy: myalgia, myositis, rhabdomyolysis and asymptomatic raised creatine kinase
- Liver impairment
- May increase risk of intracerebral haemorrhage in those who’ve previously had a stroke
What are 5 risk factors for myopathy (myalgias, rhabdomyolysis) when taking statins?
- Advanced age
- Female sex
- Low BMI
- Presence of multisystem disease e.g. diabetes mellitus
- More common in lipophilic statins (simvastatins, atorvastatin) than relatively hydrophilic (rosuvastatin, pravastatin, fluvastatin)
What monitoring is recommended when prescribing statins?
- LFTs: baseline, 3 months and 12 months
When should treatment with statins be discontinued based on monitoring blood tests?
If serum transaminase (LFTs essentially) concentrations rise to and persist at 3 times the upper limit of the reference range
What are 3 contraindications to statins?
- Avoid in patients with history of intracerebral haemorrhage - risk of recurrence
- Macrolides (e.g. erythromycin, clarithromycin) - important interaction, stop statins until course completed
- Pregnancy
What are 4 groups of people who should receive a statin?
- All people with established cardiovascular disease: stroke, TIA, ischaemic heart disease, peripheral arterial disease
- Anyone with 10 year cardiovascular risk >10% (QRISK)
- Assess pts with T2DM with QRISK2 to determine whether to start
- T1DM diagnosed > 10 years ago OR aged >40y OR have established nephropathy
When should statins be taken and why?
At night - when the majority of cholesterol synthesis takes place
especially true for simvastatin - shorter half life than others
What statin type and dose is recommended for primary and secondary prevention of cardiovascular disease?
- Atorvastatin 20mg od for primary prevention
- Increase dose if non-HDL has not fallen by >40% up to 80mg
- Atorvastatin 80mg od for secondary prevention
What 2 categories can treatment with statins be divided into?
- Primary prevention of CVD
- Secondary prevention
What are 3 scenarios when statins are used for primary prevention of CVD?
- 10-year cardiovascular risk >10%
- most type 1 diabetics
- CKD if eGFR <60
What are 3 examples of when statins can be used for secondary prevention of CVD?
- Known ischaemic heart disease
- Cerebrovascular disease
- Peripheral arterial disease
At what age should you start to assess for QRISK and therefore treatment with statins?
40 years
What is the maximum age at which to use QRISK2 for CVD risk assessment and why?
84; >85 years are at high risk due to age
What are 3 patient groups in whom the QRISK2 assessment tool should not be used and why?
- type 1 diabetics
- patients with an estimated glomerular filtration rate (eGFR) less than 60ml/min and/or albuminuria
- patients with a history of familial hyperlipidaemia