Case Study #1
A 55 y.o. female with a history of hypertension, hypercholesterolemia, peripheral arterial disease, and renal insufficiency presented to the emergency room with progressive muscle pain, weakness, and lethargy. Initially she noted diffuse arm and leg pain 2 weeks earlier, but attributed her pain to peeling numerous bags of potatoes the previous day. Medications at time of presentation include naproxen, cyclobenzaprine, amlodipine, benezepril, metoprolol, cerivastatin, and gemfibrozil. Her physician had initiated both cerivastatin and gemfibrozil 1 month earlier for treatment of elevated LDL and triglycerides. She denies recent trauma, excessive exercise, infection, seizure, or alcohol use. BP was 170/70. Diffuse tenderness to palpation was noted along her arms and legs with normal strength and sensation. Labs: potassium 8.5 mmol/L, creatinine 8.0 mg/dl, BUN 135 mg/dl, CPK 22,770 U/L. EKG shows PR lengthening, QRS prolongation, and peaked T waves.
1. What is the differential diagnosis for this patient?
2. Are there drug interactions or pharmacogenetic factors that could be contributing to the patient’s symptoms? If so, explain the factors and mechanism?
