Acipimox (trade name Olbetam in Europe) is a niacin derivative used as a hypolipidemic agent. It is used in low doses and may have less marked adverse effects, although it is unclear whether the recommended dose is as effective as are standard doses of nicotinic acid. Acipimox inhibits the production of triglycerides by the liver and the secretion of VLDL cholesterol, which leads indirectly to a modest reduction in LDL and increase in HDL cholesterol. Long-term administration is associated with reduced mortality, but unwanted effects limit its clinical use. Adverse effects include flushing (associated with prostaglandin D2), palpitations, and gastrointestinal disturbances. Flushing can be reduced by taking aspirin 20 to 30 minutes before taking acipimox. High doses can cause disorders of liver function, impair glucose tolerance and precipitate gout.