Lipid Management in Special Populations
NEW ORLEANS, LA—Statins are the most widely prescribed agents in the world. While muscle-related adverse effects associated with statins are well known, accurately quantifying their incidence to guide clinicians with respect to lipid management can be difficult, said Richard H. Karas, MD, PhD, Tufts Medical Center, Boston, at ACC.11, the American College of Cardiology's 60th Annual Scientific Session.
Dose, body size, age, concomitant use of CYP450 inhibitors, and other drug-drug interactions all can affect statin tolerability and should be investigated in a patient with a complaint of myalgia. In many cases, an adverse event may be related to a concomitant medication. A study of adverse events of statins reported to the U.S. Food and Drug Administration found 58% of all statin-associated myopathy included such medications, Dr. Karas said.
Another challenge is that no patient-specific test exists that can detect statin-related myalgia in one patient vs. another. Studies of myalgia incidence have ranged from being no different than placebo to as high as 25%. To date, no evidence has linked extent of LDL lowering and rhabdomyolysis.
Dr. Karas said evidence of microscopic musculoskeletal damage in those treated with statins is reason enough for him to secure baseline, prestatin creatinine phosphokinase (CPK) levels on all patients. In asymptomatic patients, further CPK screening is not advised; however, if tested, the statin should be continued unless CPK levels are >10 times the upper limit of normal (10xULN). In symptomatic patients, a CPK level should be checked; if normal, the statin should be continued. If <10xULN, the statin should be continued but risks and benefits should be reconsidered. Patients who have had rhabdomyolysis should not have a statin re-initiated, he said.
Lipid management in patients with HIV, renal insufficiency, the elderly, and the transplant population were also addressed during a symposium at ACC.11.
- The population of patients with HIV represent a challenging group for lipid management, particularly if underlying viremia has not been addressed. In those who are acutely viremic, treatment for HIV “trumps lipid concerns,” said James H. Stein, MD, of the University of Wisconsin, Madison. Previously, mortality from HIV was so high, there was little concern about cardiovascular disease. However, as some patients with HIV are now living more than three decades and the disease is increasingly being viewed as a chronic disease, the challenge is how best to manage lipids, especially since statins not only appear to be less effective in this population, they interact with the majority of agents used to treat HIV. For these reasons, Dr. Stein said, he recommends cardiologists work closely with the provider treating the patient's HIV or a clinical pharmacologist to be sure the patient not harmed by treatment.
- The use of statins in patients with renal insufficiency has primarily been studied in end-stage renal disease (ESRD), said Peter A. McCullough, MD, MPH, of Providence Park Healthcare System in Novi, MI. In general, statins increase proteinuria slightly, but only when triglyceride levels rise above 500mg/dL do guidelines call for treatment. In addition, the relative impact in lowering lipids and influencing mortality in this population is less than that observed in the people without chronic kidney disease. Fenofibrate has been shown to reduce renal blood flow, which may be protective.
- A treatment-risk paradox exists in managing lipids in the increasingly elderly population, especially those ≥80 years, said Laurence S. Sperling, MD, of Emory University School of Medicine, Atlanta, GA. Benefits of treatment include secondary prevention of coronary heart disease (CHD), a reduction in stroke, and decreased morbidity; risk includes altered metabolism, drug-drug-interactions, side effects, and cost. Data are scant with respect to primary prevention for CHD and there are no data regarding dietary modifications or the use of nonstatins or combination therapy. Older patients are also at risk for polypharmacy; one study found 47% of patients ≥75 years of age and older were prescribed at least five medications.
- Patients who have undergone kidney, heart, liver, and lung transplants should be treated lipid levels are elevated, said Jon A. Kobashigawa, MD, Cedars-Sinai Medical Center, Los Angeles, CA. When indicated, doses of statins approximately one-half of that given a nontransplant population should be initiated as soon as possible following transplant and continued, even if the treatment goal is not achieved. Agents that should not be used concomitantly with statins in the transplant population include fibrates and macrolide antibiotics.