Discontinuation rates of cholesterol-lowering medications: implications for primary care

To evaluate long-term continuation rates for cholesterol-lowering therapy (niacin, sequestrants, statins) in a multidisciplinary lipid clinic and to evaluate the effectiveness of 2 different dosing strategies designed to improve long-term continuation of therapy.

An observational study was done at the Milwaukee Department of Veterans Affairs Medical Center Lipid Clinic, where healthcare personnel were trained to improve patient tolerance to cholesterol-lowering medications. Primary outcomes were recorded prospectively.

Patients were 970 consecutive veterans who began therapy with niacin, sequestrants, or statins between March 1988 and December 1995. In 1992, two different dosing strategies were initiated to reduce the discontinuation rates for niacin and sequestrants: (1) the niacin titration schedule was lengthened from 3 to 6 weeks and (2) the initial sequestrant dose was reduced from four to two scoops daily.

Discontinuation rates for niacin and sequestrants were both very high. For niacin, 48% and 71% of all patients who began therapy discontinued the drug by 1 and 4 years, respectively. For sequestrants, drug discontinuation rates were 59% and 83% at 1 and 4 years, respectively. On the other hand, statin discontinuation rates at 1 and 4 years were only 10% and 28%, respectively. Neither the longer niacin titration schedule nor the lower sequestrant initiation dose reduced these high discontinuation rates.

Despite initiation of niacin and sequestrant therapy in the setting of a multidisciplinary lipid clinic, drug discontinuation rates were high and were similar to rates observed in primary-care settings. Neither the specialized resources available in a lipid clinic nor protocols designed to improve tolerance to therapy reduced the high drug discontinuation rate. Unless more tolerable niacin and sequestrant formulations become available, reliance on statins as the preferred cholesterol-lowering agents will continue because they have fewer side effects and lower discontinuation rates.