During a routine follow-up visit, a 62-year-old male patient reports a two-week history of bilateral thigh and shoulder pain accompanied by mild weakness. His medical history is significant for a myocardial infarction 6 months prior, and his current daily medication regimen includes aspirin, metoprolol, lisinopril, and atorvastatin 80 mg. Vital signs are within normal limits. On physical examination, there is noticeable tenderness upon palpation of the quadriceps and deltoid muscles bilaterally, and proximal muscle strength is graded at 4/5.
Laboratory studies are obtained and reveal the following:
| Parameter | Patient Value | Reference Range |
|---|---|---|
| Serum creatinine | 1.1 mg/dL | 0.6-1.2 mg/dL |
| Creatine kinase | 1,850 U/L | 40-250 U/L |
| Thyroid-stimulating hormone | 2.5 mU/L | 0.5-5.0 mU/L |
| Urinalysis | Negative for blood and protein | Negative |
Which of the following is the most appropriate next step in the management of this patient?
- Discontinue atorvastatin and reassess the patient in 2 to 4 weeksAnswer
- BAdminister aggressive intravenous crystalloid hydration
- CContinue atorvastatin and add daily coenzyme Q10 supplementation
- DOrder electromyography and nerve conduction studies
- EObtain magnetic resonance imaging of the bilateral lower extremities
Answer
The correct answer is to discontinue the statin therapy and re-evaluate the patient's symptoms and laboratory values in 2 to 4 weeks.
The correct action is to discontinue the statin and reassess the patient in 2 to 4 weeks. Statin-induced myopathy is a known adverse effect characterized by muscle pain, tenderness, or weakness accompanied by an elevated creatine kinase (CK) level. When a patient develops intolerable muscle symptoms or has a CK level greater than 4 times the upper limit of normal (as seen in this patient with a CK of 1,850 U/L), the statin should be stopped promptly. Continuing the medication risks progression to severe rhabdomyolysis and acute kidney injury. Once the patient's symptoms resolve and the CK normalizes, it is appropriate to rechallenge the patient with a different statin or a lower dose, as lipid-lowering therapy remains crucial for secondary prevention after a myocardial infarction.
Step-by-Step Solution
Key Concept
Management of statin-induced myopathy requires prompt discontinuation of the offending agent when symptoms are accompanied by a creatine kinase level greater than 4 times the upper limit of normal.
Estimated Time:1m 30s