Both Niaspan and lovastatin (Mevacor®) are approved by the United States Food and Drug Administration (FDA) to treat high cholesterol. Niacin ER/Lovastatin (Advicor®), a combination of these two drugs, is also approved by the FDA to treat high cholesterol. The use of Niacin ER/Lovastatin to treat narrowing of leg arteries and relieve “intermittent claudication” (leg pain caused by narrowing of the arteries in the leg) is considered investigational. An investigational use is one that is not approved by the FDA.