There are a number of drugs that can potentially cause severe side effects or complications when taken with lovastatin. When lovastatin is taken with medicines such as HIV protease inhibitors, antifungals, or niacin, your body may metabolize the drugs differently than intended. For example, certain drug interactions with lovastatin can increase your risk for developing serious muscle problems.
Grapefruit juice and grapefruit products, including supplements.
Some of these drug interactions with lovastatin may increase your risk for developing serious muscle problems (see Mevacor and Muscle Pain). If you experience unexplained muscle pain, tenderness, or weakness while taking lovastatin (especially if you also have a fever or feel ill), it is important to contact your healthcare provider immediately.