Diltiazem CD ER

Diltiazem CD ER Diltiazem CD is an extended-release capsule used for hypertension. Often used in combination with lifestyle changes, the medication can help lower blood pressure by relaxing the blood vessels and reducing the strain on the heart. Controlling hypertension can reduce the risk of stroke and cardiovascular issues. Read more about hypertension.
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How to use this information
This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective or appropriate for you. This information is not individual medical advice and does not substitute for the advice of a medical provider. If you have any questions, go to your patient dashboard and request a callback for complete information about this product and your specific health needs.
Medication name




What you should know about Diltiazem
  • Diltiazem is used to treat high blood pressure (hypertension) and prevent chest pain (angina). Lowering high blood pressure helps prevent strokes, heart attacks and kidney problems.
  • When used regularly, Diltiazem can decrease the number and severity of chest pain episodes from angina. It may help increase your ability to exercise.
  • Diltiazem is a calcium channel blocker that works by relaxing blood vessels in the body and heart so blood can flow more easily. It also lowers your heart rate. These effects help the heart work less hard and lower blood pressure.
  • Long-acting forms of Diltiazem may be used for high blood pressure. If your medical provider prescribes Diltiazem for high blood pressure, check with your pharmacist to make sure you are getting the right form of the drug.
How to take Diltiazem
  • Take this medication by mouth with or without food, usually once daily or as directed by your medical provider. Swallow the capsules whole. Do not crush or chew the capsules, as doing so can release all of the drug at once and increase your risk of side effects.
  • Avoid red rice yeast and grapefruit juice while you are taking this medication.
  • Your medical provider may gradually increase your dose. Follow their instructions carefully. The dosage is based on your medical condition, response to treatment and other medications you may be taking. Be sure to tell your medical provider and pharmacist about all the products you use, including prescription drugs, nonprescription drugs and herbal products.
  • Use this medication regularly to get the most benefit from it. To help you remember, use it at the same time each day. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick. For the treatment of high blood pressure, it may take 2 to 4 weeks before you get the full benefit of this drug.
  • 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 Nitroglycerin placed under the tongue) to relieve an angina attack as directed by your medical provider. Consult your medical provider or pharmacist for details.
  • Tell your medical provider if your condition worsens—for example, your chest pain worsens or your routine blood pressure readings increase.
Potential side effects
  • Dizziness, lightheadedness, weakness, nausea, flushing, constipation and headache may occur. If any of these effects last or get worse, tell your medical provider or pharmacist right away.
  • 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 medical provider has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not experience serious side effects. Tell your medical provider right away if you experience any serious side effects, including:

    • Nausea or vomiting that doesn't stop
    • Fainting
    • New or worsening symptoms of heart failure such as shortness of breath, swelling ankles or feet, unusual tiredness or unusual/sudden weight gain
    • Slow, irregular, pounding or fast heartbeat
    • Mental or mood changes such as depression or agitation
    • Unusual dreams
    • Severe stomach or abdominal pain
    • Dark urine
    • Yellowing eyes or 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 or 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, request a callback for medical advice. You may also report side effects to the FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

Precautions to be aware of
  • Before taking Diltiazem, tell your medical provider or pharmacist if you are allergic to it or have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Go to your patient dashboard and request a callback for more details.
  • Before using this medication, tell your medical provider or pharmacist your medical history, especially of:

    • Certain types of heart rhythm problems such as sick sinus syndrome or atrioventricular block
    • Liver disease
    • Kidney disease
    • Heart failure
  • This drug may make you dizzy. Alcohol or marijuana (cannabis) can exacerbate the effect. Do not drive, use machinery or do anything that requires alertness until you can do it safely. Limit alcoholic beverages. Talk to your medical provider if you are using marijuana.
  • 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 there is a clear need. Discuss the risks and benefits with your medical provider.
  • This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your medical provider before breastfeeding.
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 medical provider and pharmacist.
  • Do not start, stop or change the dosage of any medicines without your medical provider's approval.
  • Digoxin and Fingolimod may interact with this drug.
  • Other medications can affect the removal of Diltiazem from your body, which may affect how it 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
    • Methadone
    • Certain benzodiazepines like Triazolam and Midazolam
    • Certain seizure medications like Carbamazepine and Phenytoin
    • Certain cholesterol medications like Lovastatin and Simvastatin
  • Some products have ingredients that could raise your heart rate or blood pressure. 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 and Naproxen.

What to do in the event of an overdose

If someone has overdosed and is experiencing serious symptoms—such as passing out or trouble breathing—call 911. If symptoms from taking this medication are less severe, call your local poison control center at 1-800-222-1222 right away.

Additional notes
  • Do not share this medication with others.
  • Talk with your medical provider about lifestyle changes that may help this medication work better such as stress reduction programs, exercise and dietary changes.
  • Lab and/or medical tests such as kidney or liver function, pulse, blood pressure and EKG may be performed while you are taking this medication. Keep all medical and lab appointments. Consult your medical provider for more details.
  • There are different brands and types of this medication available. Many do not have the same effects. Do not change brands or types without consulting your medical provider or pharmacist.
  • Have your blood pressure and pulse (heart rate) checked regularly while taking this medication. Learn how to check your own blood pressure and pulse at home, and share the results with your medical provider.
What to do if you miss a dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

How to store this medication
  • Store at room temperature away from light and moisture. Do not store in the bathroom. 
  • Keep all medications away from children and pets.
  • Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more information.
Treatment for
Generic Name
Diltiazem CD ER
Diltiazem CD ER
Drug Class
Calcium channel blocker (CCB)

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