Cardizem CD (active ingredient: diltiazem hydrochloride) is a prescription medication used to treat high blood pressure, chronic stable angina, and certain abnormal heart rhythms.
Cardizem CD is an extended-release form of diltiazem. This means the medication is released slowly over time to provide longer-lasting effects throughout the day.
High Blood Pressure
Cardizem CD is used to treat high blood pressure, also called hypertension.
High blood pressure occurs when blood pushes against the walls of the arteries with too much force over a long period of time. It often does not cause noticeable symptoms, but it can gradually damage the heart, blood vessels, kidneys, and other organs.
If high blood pressure is not controlled, it may increase the risk of:
- Heart attack
- Stroke
- Heart failure
- Kidney problems
- Damage to the blood vessels
Cardizem CD helps lower blood pressure by relaxing and widening the arteries. This allows blood to flow more easily and reduces the amount of resistance the heart has to pump against.
Chronic Stable Angina
Cardizem CD may also be used to manage chronic stable angina.
Angina is chest pain or discomfort that occurs when the heart muscle does not receive enough oxygen-rich blood. Chronic stable angina often happens during physical activity, emotional stress, or other situations that increase the heart’s need for oxygen.
Symptoms may include:
- Pressure or squeezing in the chest
- Chest tightness
- Burning or aching discomfort
- Pain that may spread to the arm, shoulder, neck, jaw, or back
- Shortness of breath
- Tiredness during physical activity
Cardizem CD helps reduce the workload on the heart and improve blood flow to the heart muscle. This may help reduce how often angina occurs and how severe the symptoms feel.
Cardizem CD is generally used to help prevent angina episodes rather than to provide immediate relief during sudden chest pain.
Supraventricular Tachyarrhythmias
Diltiazem may also be used to help control certain abnormal heart rhythms that begin above the ventricles, the lower chambers of the heart.
These abnormal rhythms may cause the heart to beat too quickly or irregularly.
Symptoms can include:
- A racing heartbeat
- An irregular heartbeat
- Heart palpitations
- Dizziness
- Weakness
- Shortness of breath
- Chest discomfort
Diltiazem helps slow the electrical signals that pass through certain parts of the heart, which can help control the heart rate.
Paroxysmal Supraventricular Tachycardia
Paroxysmal supraventricular tachycardia, or PSVT, is a type of abnormal heart rhythm that causes the heart to suddenly beat very fast.
Episodes can begin and end suddenly and may last for a few minutes or longer.
Diltiazem can slow electrical conduction through the heart and may help control certain episodes of rapid heart rhythm.
Atrial Fibrillation
Diltiazem may also be used to help control the heart rate in some people with atrial fibrillation, commonly called AFib.
Atrial fibrillation is an irregular heart rhythm that begins in the upper chambers of the heart.
Instead of beating in a steady pattern, the upper chambers beat irregularly, which can cause the lower chambers to beat too quickly.
Diltiazem slows electrical signals traveling through the atrioventricular, or AV, node. This can help reduce the heart rate and make symptoms easier to manage.
How Cardizem CD Works
Cardizem CD belongs to a group of medications called calcium channel blockers.
Calcium plays an important role in helping the heart muscle and blood vessel muscles contract. Diltiazem blocks some of the calcium from entering these muscle cells.
This produces several effects that can help treat cardiovascular conditions.
Relaxes and Widens Blood Vessels
Cardizem CD relaxes the smooth muscles in the walls of the arteries.
When the arteries widen, blood can flow through them with less resistance.
This helps lower blood pressure and reduces the amount of work the heart must do to pump blood throughout the body.
Reduces the Heart’s Workload
Diltiazem can reduce how strongly the heart contracts and may slow the heart rate.
This lowers the amount of oxygen the heart needs and may help prevent episodes of chronic stable angina.
Improves Blood Flow to the Heart
Cardizem CD can help improve blood flow through the coronary arteries that supply oxygen-rich blood to the heart muscle.
Improved blood flow may help reduce chest discomfort caused by chronic stable angina.
Slows Electrical Signals in the Heart
Diltiazem also affects the electrical system that controls the heartbeat.
It slows electrical conduction through the AV node, which helps control how quickly signals travel from the upper chambers of the heart to the lower chambers.
This effect can help slow a rapid heart rate in certain supraventricular arrhythmias.
Extended-Release Formulation
Cardizem CD is an extended-release medication designed to release diltiazem gradually over an extended period.
This helps maintain a more consistent amount of medication in the body and may allow once-daily dosing in many patients.
Because it is an extended-release product, it should be taken exactly as directed. Do not crush or chew the capsule unless your healthcare provider or pharmacist specifically confirms that your particular product can be altered.
What to Expect During Treatment
Cardizem CD is usually taken regularly every day.
You may not feel an obvious difference when taking it for high blood pressure because hypertension often has no noticeable symptoms.
If you are taking Cardizem CD for angina, you may notice that chest pain occurs less often or that you are able to perform activities with less discomfort.
If diltiazem is being used to control your heart rate, your healthcare provider may check your pulse or perform an electrocardiogram to see how well treatment is working.
Monitoring During Treatment
Your healthcare provider may monitor your:
- Blood pressure
- Heart rate
- Heart rhythm
- Angina symptoms
- Response to treatment
- Possible side effects
Regular monitoring helps determine whether the medication is working safely and effectively.
Important Treatment Considerations
Take Cardizem CD exactly as prescribed by your healthcare provider.
Do not increase, decrease, or stop your dose without medical advice. Stopping treatment may cause your blood pressure, angina, or heart rhythm problem to worsen.
Tell your healthcare provider about all prescription medicines, over-the-counter products, vitamins, and supplements you take because diltiazem can interact with other medications.
Contact your healthcare provider if you develop severe dizziness, fainting, a very slow heartbeat, worsening shortness of breath, significant swelling, or chest pain that becomes more frequent or severe.
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