Statins Flashcards
Give 4 examples of statins
- Atorvastatin
- Pravastaitn
- Rosuvastatin
- Simvastatin
What is the mechanism of action of statins?
- Competitively inhibit HMG CoA reductase through melavolanate pathway
- Upregulate hepatic LDL receptors so increased hepatic clearance of circulating LDL
- So reduces serum cholesterol
- Also causes an increase in HDL cholesterol
What is the route of delivery of statins?
PO
When should statins be taken?
Some statins work better in evening, whereas others can be taken at any time
What are the indications for statins?
- Primary prevention of CVD
- Secondary prevention of CVD
- Hypercholesterolaemia
What are the contraindications to statins?
Pregnancy and breastfeeding
When should statins be discontinued in pregnancy?
3 months prior to conception
Why should statins be discontinued in pregnancy?
Risk of congenital abnormalities
When should statins be used with caution?
- Renal or hepatic impairment
- High alcohol intake
What should be done with statins in renal or hepatic impairment?
Prescribe lower doses
Why should statins be used with caution in people with high alcohol intake?
Increased risk of hepatic damage
What might interact with statins?
- CYP450 inhibitors
- Clarithromycin
- Amlodipine
- Fusidic acid
- Grapefruit and its juice
What should be done if a patient on statins needs clarithromycin?
Statin should be withheld during clarithromycin course
What should be done if a patient on statins needs amlodipine?
Dose adjustment of simvastatin may be required, as the maximum dose of simvastatin with amlodipine is 20mg
When might statins interact with fusidic acid?
If used at the same time, or within 7 days of last dose of fusidic acid
What might happen if statins are given with fusidic acid?
Increased disk of fatal rhabdomyolysis
What statins are known to interact with grapefruit and its juice?
Simvastatin and atorvastatin
What monitoring is required with statins?
- Full lipid profile (HDL, non-HDL + triglycerides) before statin
- Check TFTs before starting statins
- Check LFTs after 3 months of therapy and after 1 year
Why should you check baseline lipids before starting statin therapy?
To monitor clinical effect of statin therapy
Why should you check TFTs before starting statin therapy?
Hypothyroidism is a reversible cause of hyperlipidaemia
Why should you check LFTs when on statin therapy?
To look for decline in hepatic function
When should statins be stopped, regarding abnormal LFTs?
If serum transaminases are 3x the upper limit of normal value
What are the common side effects of statins?
- Headache
- GI disturbance
- Mild muscle aches to severe muscle toxicity
- Rise in serum liver enzymes, especially ALT
What are the rare side effect of statins?
Rhabdomyolysis
What patient counselling is required with statins?
- Side-effects and rhabdomyolysis
- Alcohol
What counselling is required regarding side-effects and rhabdomyolysis with statins?
Although statins are well tolerated by most people, side effects should be explained to patients. Tell patient to report any muscle symptoms to their GP. Warn patient to seek medical help urgently if they have rust-coloured urine
What are the symptoms/signs of rhabdomyolysis?
- Severe muscle pain
- Weakness
- Myoglobinuria
What should be done if the patient has any symptoms of rhabdomyolysis, or you suspect it?
Check CK
What counselling is required regarding alcohol with statins?
Advice patients to keep alcohol intake low
Why are statins recommended to be taken at night?
Most cholesterol is produced overnight
Why is statin not recommended during pregnancy?
Cholesterol important for fetal development
How does grapefruit juice interact with statins?
CYP3A4 inhibition so plasma statin levels increase
What is another fruit that interacts with statins similarly to grapefruit?
- Lime
- Other citrus fruits (containing furanocoumarins)
Name some high intesnity statins
atorvastatin and rosuvastatin
What are some low-medium intensity statins?
Pravastatin
Fluvastatin
Simvastatin
What to do if patient cannot tolerate statins?
Or cholesterol not adequately controlled?
- Offer ezetimibe instead
or add ezetimibe if statin dose increase is not possible
What is the nocebo effect with regard to statins?
- Pt stops taking statin due to perceived side effects (MSK pain)
- Side effects likely not actually caused by statin = nocebo effect
Why is bempedoic acid used with statins?
- Slows excretion of statin
