Grapefruit is a healthy addition to a well-balanced diet. However, the fruit has been shown to affect the metabolism of many medications, increasing the risk of toxicity and adverse effects. Grapefruit and grapefruit juice may interact with diltiazem and lead to unwanted side effects. Discuss the use of grapefruit products with your doctor. Discuss the use of grapefruit products with your doctor. Grapefruit and grapefruit juice may interact with diltiazem. Your doctor may advise you to follow a low-sodium diet while taking diltiazem. This medication may impair your thinking and reaction time. Find patient medical information for Diltiazem Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. 51 patient posts about Grapefruit and its potential interaction with Diltiazem based on the insights of millions of patients and trusted online health resources. Diltiazem can interact with grapefruit and grapefruit juice and the interaction may have dangerous effects. Diltiazem is in the FDA pregnancy category C. This means that it is not known whether diltiazem will be harmful to an unborn baby. Grapefruit juice may also increase the effects of dilTIAZem in some people by increasing its levels in the blood. You may want to limit alcohol intake and avoid excessive consumption of grapefruit and grapefruit juice during treatment with dilTIAZem. However, if you have been regularly consuming grapefruit or grapefruit juice with dilTIAZem, do not alter the amounts of these products in your. Grapefruit and grapefruit juice may interact with diltiazem and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor. Discuss the use of grapefruit products with your doctor. Common Questions and Answers about Diltiazem and grapefruit juice tiazac So, I just poured myself a glass of grapefruit juice and took my medicine - then for some reason I remembered that grapefruit juice interacts with some medications. WebMD provides information about interactions between Diltiazem Oral and avoid-grapefruit-unless-md-instructs-otherwise.