Adverse effects of statins

Some people who take statins experience muscle pain, cramps and/or weakness. Although data from clinical trials suggest that the numbers do not differ much between those patients allocated to active treatment or placebo, in clinical practice, a significant minority of patients will complain of this side effect. It is most likely to occur in the first three to 12 months of treatment and may be more common in people with underlying comorbidities, such as renal impairment or untreated hypothyroidism. It is also more common with increasing age, Asian ethnicity, female gender, or as a result of drug interactions.

If a patient reports side effects suggesting muscle problems with a statin, a blood test for creatine kinase (CK) should be undertaken. If there is only a mild increase in CK with tolerable symptoms, the patient can be reassured and, in most cases, the statin can be continued unchanged.

For more symptomatic patients or those with a larger rise in CK, alternative strategies will be needed, depending on severity of the symptoms, magnitude of the rise in CK and clinical urgency. More detailed guidance can be found in the national Statin intolerance pathway.

Other adverse effects or cautions with statins include:

• Liver toxicity: Statins are contraindicated in active liver disease
• New onset diabetes: Some people who take statins are at greater risk
  of diabetes
• Common side effects (one in 10) include allergic reactions, headache, nausea, gastrointestinal disturbances, inflammation of the nasal passages, pain in the throat or nose bleeds.

Statins are contraindicated in pregnancy and in those who are breastfeeding.