Mr B is 78 years old and has taken simvastatin since 1990. In 1995 he started amiodarone 200 mg daily, but within four months he developed bilateral pain in biceps and thigh muscles. These symptoms have continued on and off since then. He initially brought these symptoms to the attention of his general practitioner, but was reassured that it was not unusual for people in their 70s to suffer from muscle aches and pains.
In late 2003, Mr B's simvastatin dose was doubled to 40 mg twice daily. His symptoms got worse and he tore a muscle while lifting a telephone book. Mr B called the Adverse Medicine Events line (AME Line) querying the possible association between simvastatin and muscle tears, after seeing a similar case reported in a newspaper article about the service. The AME Line classified Mr B as a possible case of statin-induced myopathy due to both a simvastatin-amiodarone drug interaction and a dosage increase. He was provided with published literature on this possible association and advised to return to his doctor for further investigation.
Follow-up revealed that Mr B had an elevated creatine kinase. His dose of simvastatin was subsequently reduced to 10 mg twice daily and ezetimibe was added to his regimen. The patient described gradual improvement of his symptoms over the following eight weeks.
The AME Line provides an opportunity for Australian consumers to contribute to post-marketing pharmacovigilance. Muscle symptoms with statins may be more common than health professionals suspect.
Checklist for statin-induced muscle symptoms
Does the patient experience:
- muscle aches, tenderness, soreness, weakness or pain, usually present in proximal muscles (e.g. trunk)
- bilateral symptoms
- decreased muscle strength (not just feeling tired)
- difficulty in:
- getting up from a chair
- holding arms above the head
- performing usual tasks (generalised difficulty)
Are any of the following concentrations increased:
- creatine kinase
- erythrocyte sedimentation rate
- C-reactive protein
- van Grootheest K, de Jong-van den Berg L. Patients' role in reporting adverse drug reactions. Expert Opin Drug Saf 2004;3:363-8.
- van Grootheest K, de Graaf L, de Jong-van den Berg L. Consumer adverse drug reaction reporting. A new step in pharmacovigilance? Drug Saf 2003;26:211-7.