Statins May Aggravate ALS but Do Not Increase its Incidence

There is a huge difference between a drug aggravating an existing disease and a drug increasing the risk of a disease.

Earlier this year, French investigators reported a profound survival benefit of hyperlipidemia in amyotrophic lateral sclerosis (ALS) and consequently advised against the use of lipid-lowering drugs (eg, statins) in patients with ALS. The French study followed a WHO pilot investigation, which suggested that the use of statins may be associated with the development of an "ALS-like syndrome."

Now the FDA is weighing in on the subject with a report in yesterday's online issue of Pharmacoepidemiology and Drug Safety. The agency's study was prompted by a disproportionate number of ALS reports associated with statin use in its Adverse Events Reporting System.

By analyzing 41 placebo-controlled statin* trials of a least 6 months' duration, the FDA calculated an ALS incidence of 5.0 cases per 100,000 patient-years with statin use and a comparable 4.2 cases per 100,000 patients-years with placebo treatment. Prevalence rates of the disease were similar in both treatment groups: 9 cases in 64,602 statin-treated patients and 10 in 56,362 placebo-treated patients.

The rate of ALS in the general population is between 1 and 2 per 100,000, but the likelihood of disease increases with age, as does the likelihood of statin treatment. Approximately 80% of statin prescriptions are dispensed to Americans older than 50 years of age. The FDA investigators also note that the incidence of ALS in the United States has remained stable during the last 20 years, but that statin use has increased 30-fold during this time period—facts that make an association between the incidence of the disease and the drug class unlikely.

Nevertheless, results of an ongoing case-control study of the relationship between ALS and statin use, anticipated in 6-9 months, should further clarify the issue.

* Atorvastatin (Lipitor; Pfizer), cerivastatin (Baycol; Bayer), fluvastatin (Lescol: Novartis), lovastatin (Mevacor; Merck), pravastatin (Pravachol; BMS), rosuvastatin (Crestor; AstraZeneca), and simvastatin (Zocor; Merck).

Update: In a study presented last week at the annual meeting of the American Neurological Association, statin-associated pain and weakness were more frequent prediagnostically in patients with sporadic ALS (sALS) who had received multiple statins or who were diabetic or hypothyroid than in patients who developed other motor neuron diseases (eg, familial ALS). The study investigators suggested that myopathic symptoms during statin treatment may herald the clinical onset of sALS in predisposed individuals. However, the statin-treated populations in this review study were small (eg, 31/164 patients with sALS), and only 3 of the sALS patients had received more than one statin. 

HT for update: Medscape Medical News