Women who use Dilt-CD (diltiazem) should take precautions to avoid pregnancy because the drug has caused birth defects in animal studies. Dilt-CD also can pass into breast milk, so women should avoid breastfeeding while taking this drug. Before your doctor prescribes Dilt-CD, he or she needs to know if you will be having surgery or dental work. Avoid grapefruit or grapefruit juice while taking Dilt-CD. It may impair your thinking or reactions. Avoid driving or operating machinery until the medicine is stabilized. Dilt-CD can make you more sensitive to sun exposure. Be sure to wear protective clothing or sunscreen.