SIDE EFFECTS: Dizziness, lightheadedness, weakness, nausea, flushing, constipation, and headache may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. To lower the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: fainting, new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain), slow/irregular/pounding/fast heartbeat, mental/mood changes (such as depression, agitation), unusual dreams, severe stomach/abdominal pain, dark urine, persistent nausea/vomiting, yellowing eyes/skin. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

HOW TO USE: Take this medication by mouth before meals and at bedtime as directed by your doctor, usually 3 to 4 times a day. Swallow the tablets whole. Do not split, crush, or chew the tablets. Doing so can release all of the drug at once, increasing the risk of side effects. Follow your doctor's directions on how to take this medication. The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Your doctor may gradually increase your dose. Follow your doctor's instructions carefully. Use this medication regularly to get the most benefit from it. To help you remember, use it at the same times each day. This medication must be taken regularly to prevent angina. It should not be used to treat angina when it occurs. Use other medications (such as sublingual nitroglycerin) to relieve an angina attack as directed by your doctor. Consult your doctor or pharmacist for details. Tell your doctor if your condition worsens (for example, your chest pain worsens or is more frequent).

PRECAUTIONS: Before taking diltiazem, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: certain types of heart rhythm problems (such as sick sinus syndrome/atrioventricular block), liver disease, kidney disease, heart failure. This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis). Before having surgery, tell your doctor or dentist that you are taking this medication. Older adults may be more sensitive to the side effects of this drug, especially dizziness, constipation, or swelling ankles/feet. During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug include: digoxin, fingolimod. Other medications can affect the removal of diltiazem from your body, which may affect how this medication works. Examples include cimetidine, St. John's wort, azole antifungals such as ketoconazole, macrolide antibiotics such as erythromycin, rifamycins including rifabutin and rifampin. This medication can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include aprepitant/fosaprepitant, asunaprevir, buspirone, colchicine, flibanserin, ivabradine, lomitapide, certain benzodiazepines (triazolam, midazolam), among others. Some products have ingredients that could raise your heart rate or worsen your chest pain. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen).

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.