Diltiazem is used to prevent chest pain (angina). It may help to increase your ability to exercise and decrease how often you may get angina attacks. Diltiazem is called a calcium channel blocker. It works by relaxing blood vessels in the body and heart and lowers the heart rate. Blood can flow more easily and your heart works less hard to pump blood.
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 your doctor has prescribed this medication because he or she 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.
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.
This medication should be used only when clearly needed during pregnancy. 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.