Starting/monitoring statin therapy

• exclude secondary causes of hyperlipidaemia e.g. diabetes, hypothyroidism, liver/renal impairment
• check baseline lipids, liver and renal function, creatine phosphokinase (CK)
• advise patient regarding medication e.g. adverse effects of statin treatment
• start statin treatment - statins should be taken in the evening for maximal effect, and require 4 weeks or more to exert their full effect on lipid concentrations
• LFT should be carried out before and within 4-6 weeks of starting statin therapy (1). Thereafter at intervals of 6 months to 1 year - earlier if clinical features of hepatotoxicity; also at the first review at 4-6 weeks - enquire about adverse effects such as itching, rash, myalgia, arthralgia, insomnia (1)
  • if satisfactory lipid control and no evidence of adverse effects then review again at 4-6 months, then 6-12 monthly
  • if unsatisfactory lipid control then measurements should be repeated 6 weeks after dosage adjustments are made until the desired lipid concentrations are achieved (2)
  • however NICE state that LFTs only need to be measured on three occasions:
    • baseline liver enzymes should be measured before starting a statin. Liver function (transaminases) should be measured within 3 months of starting treatment and at 12 months, but not again unless clinically indicated
    • people who have liver enzymes (transaminases) that are raised but are less than 3 times the upper limit of normal should not be routinely excluded from statin therapy
• treatment should be discontinued if serum transaminase concentrations rise to, and persist at, 3x normal range
• patients must be advised to report any unexpected muscle pain. Statins have been associated with the development of myositis, myopathy and myalgia. Some suggest if there is a marked elevation in creatine kinase concentration (>10 times the upper limit of normal) and a diagnosis of myopathy is suspected then the statin therapy should be stopped; however it has also been suggested that if the creatine kinase level is >5x the upper limit of normal then treatment should be stopped, while the patient is adequately monitored for muscular symptoms and cardiovascular risk (4)

NICE guidance states:

• primary prevention
  • offer atorvastatin 20 mg for the primary prevention of CVD (cardiovascular disease) to people who have a 10% or greater 10-year risk of developing CVD
    
    
• secondary prevention
  • start statin treatment in people with CVD with atorvastatin 80 mg. Use a lower dose of atorvastatin if any of the following apply:
    • potential drug interactions
    • high risk of adverse effects
    • patient preference

Reference:

• (1) Prescriber 2000; 11 (23): 77-85.
• (2) Scottish Intercollegiate Guidelines Network (SIGN). Lipids and primary prevention of coronary heart disease. A National Clinical Guideline. www.sign.ac.uk [September 1999]
• (3) BNF 2.12
• (4) Current Problems in Pharmacovigilance 2002; 28: 8-9.
• (5) NICE (February 2023).Lipid modification - Cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease