Diltiazem CD 300mg Capsules (24 Hr)
It is used to treat high blood pressure.It is used to treat some types of chest pain (angina).It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antihypertensive, Antianginal, Antiarrhythmic
Pharmacologic Class
Non-dihydropyridine Calcium Channel Blocker
Pregnancy Category
Category C
FDA Approved
Sep 1991
DEA Schedule
Not Controlled
Overview
What is this medicine?
Diltiazem is a medication that helps relax blood vessels and slow down your heart rate. This can lower your blood pressure, help prevent chest pain (angina), and control certain irregular heart rhythms. It works by blocking calcium from entering heart and blood vessel cells.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, it's essential to take it as directed by your doctor. Carefully read all the information provided with your prescription, and follow the instructions closely. Take your medication at the same time every day to establish a routine. Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start feeling better.
Some medications may need to be taken with food, while others should be taken on an empty stomach. It's crucial to check with your pharmacist to determine the best way to take your specific medication. Additionally, some products can be opened and mixed with a spoonful of applesauce, while others must be swallowed whole. Consult with your pharmacist to see if your medication can be opened.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication, store it at room temperature, protected from light, and in a dry place. Avoid storing your medication in a bathroom. Keep all medications in a secure location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method, and consider participating in a drug take-back program in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To get the most benefit from your medication, it's essential to take it as directed by your doctor. Carefully read all the information provided with your prescription, and follow the instructions closely. Take your medication at the same time every day to establish a routine. Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start feeling better.
Some medications may need to be taken with food, while others should be taken on an empty stomach. It's crucial to check with your pharmacist to determine the best way to take your specific medication. Additionally, some products can be opened and mixed with a spoonful of applesauce, while others must be swallowed whole. Consult with your pharmacist to see if your medication can be opened.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication, store it at room temperature, protected from light, and in a dry place. Avoid storing your medication in a bathroom. Keep all medications in a secure location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method, and consider participating in a drug take-back program in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take the capsule whole; do not crush, chew, or divide it.
- Take at approximately the same time each day.
- Continue to take as prescribed, even if you feel well.
- Monitor your blood pressure and heart rate regularly as advised by your doctor.
- Limit alcohol consumption, as it can increase the blood pressure-lowering effect.
- Avoid grapefruit and grapefruit juice, as they can increase the amount of diltiazem in your body.
- Maintain a healthy diet (low in sodium, saturated fats), regular exercise, and manage stress as part of your overall treatment plan.
- Inform your doctor or dentist that you are taking diltiazem before any surgery or dental procedures.
Available Forms & Alternatives
Available Strengths:
- Diltiazem SR 120mg Capsules (12 Hr)
- Diltiazem ER 90mg Capsules (12 Hr)
- Diltiazem ER 60mg Capsules (12 Hr)
- Diltiazem XR 120mg Capsules (24 Hr)
- Diltiazem 30mg Tablets
- Diltiazem 120mg Tablets
- Diltiazem 90mg Tablets
- Diltiazem XR 240mg Capsules (24 Hr)
- Diltiazem 60mg Tablets
- Diltiazem ER 180mg Caps (xr-24h)
- Diltiazem ER 360mg Capsules (24 Hr)
- Diltiazem ER 360mg (24 Hr/cd) Caps
- Diltiazem ER 420mg Tablets
- Diltiazem ER 180mg Capsules (24 Hr)
- Diltiazem ER 240mg Capsules (24 Hr)
- Diltiazem ER 420mg Capsules (24 Hr)
- Diltiazem ER 240mg Tabs (la 24hr)
- Diltiazem ER 120mg Capsules (24 Hr)
- Diltiazem ER 300mg Capsules (24 Hr)
- Diltiazem Hcl ER 180mg Tablets
- Diltiazem ER 300mg Capsules (24 Hr)
- Diltiazem ER 360mg Tablets (la 24h)
- Diltiazem ER 180mg Capsules
- Diltiazem ER 360mg Capsules (24 Hr)
- Diltiazem Hcl ER 180mg Tablets
- Diltiazem ER 360mg Tablets (la 24h)
- Diltiazem ER 300mg Tablets (la 24h)
- Diltiazem CD 240mg Capsules (24 Hr)
- Diltiazem CD 300mg Capsules (24 Hr)
- Diltiazem CD 180mg Capsules (24 Hr)
- Diltiazem ER 360mg (24 Hr/cd) Caps
- Diltiazem CD 120mg Capsules (24 Hr)
- Diltiazem CD 240mg Capsules (24 Hr)
- Diltiazem CD 180mg Capsules (24 Hr)
- Diltiazem CD 120mg Capsules (24 Hr)
- Diltiazem ER 360mg (24 Hr/cd) Caps
- Diltiazem CD 300mg Capsules (24 Hr)
- Diltiazem CD 180mg Capsules (24hr)
- Diltiazem ER 120mg Tablets (la 24h)
- Diltiazem ER 120mg Tablets (la 24h)
- Diltiazem 5mg/ml Inj, 5ml
- Diltiazem 125mg/25ml Inj, 25ml
- Diltiazem 50mg/10ml Inj, 10ml
- Diltiazem 100mg Inj, 1 Vial
Dosing & Administration
Adult Dosing
Standard Dose:
300 mg orally once daily
Dose Range:
120 - 540 mg
Condition-Specific Dosing:
hypertension:
180-420 mg orally once daily, titrate based on response
chronicStableAngina:
120-480 mg orally once daily, titrate based on response
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended, monitor for adverse effects.
Moderate:
No specific adjustment recommended, monitor for adverse effects.
Severe:
Use with caution, consider lower initial doses and careful titration. Monitor for exaggerated effects.
Dialysis:
Not significantly removed by dialysis. No specific supplemental dose needed, but monitor for adverse effects.
Hepatic Impairment:
Mild:
No specific adjustment recommended, monitor for adverse effects.
Moderate:
Use with caution, consider lower initial doses and careful titration. Monitor for exaggerated effects.
Severe:
Contraindicated in severe hepatic impairment due to extensive hepatic metabolism and potential for accumulation. Use with extreme caution if at all.
Pharmacology
Mechanism of Action
Diltiazem is a non-dihydropyridine calcium channel blocker that inhibits the influx of extracellular calcium ions across the myocardial and vascular smooth muscle cell membranes. This leads to relaxation of vascular smooth muscle and coronary vasodilation, resulting in decreased peripheral vascular resistance and reduced blood pressure. In the heart, it decreases sinoatrial (SA) and atrioventricular (AV) nodal conduction, prolonging the effective refractory period and slowing heart rate, which reduces myocardial oxygen demand.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 40-65% (due to first-pass metabolism)
Tmax:
Approximately 10-14 hours (for CD formulation)
FoodEffect:
Food may slightly increase bioavailability but is generally not clinically significant; can be taken with or without food.
Distribution:
Vd:
Approximately 3-13 L/kg
ProteinBinding:
70-80%
CnssPenetration:
Limited
Elimination:
HalfLife:
Approximately 5-10 hours (for CD formulation, terminal half-life)
Clearance:
Approximately 0.6-1.3 L/hr/kg
ExcretionRoute:
Primarily renal (60-65% as metabolites), fecal (35% as metabolites)
Unchanged:
Less than 4% (renal)
Pharmacodynamics
OnsetOfAction:
Within 30-60 minutes (for immediate release), prolonged for CD formulation
PeakEffect:
Approximately 2-3 hours (for immediate release), 6-11 hours (for CD formulation)
DurationOfAction:
24 hours (for CD formulation)
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Attention Immediately
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Severe dizziness or fainting
Slow heartbeat
Abnormal heartbeat that is new or worsening
Worsening heart failure (if you have a history of heart failure), characterized by:
+ Shortness of breath
+ Significant weight gain
+ Swelling in the arms or legs
Severe skin reactions, including:
+ Stevens-Johnson syndrome (SJS)
+ Toxic epidermal necrolysis (TEN)
+ Other severe skin reactions, which may be life-threatening
+ Signs of severe skin reactions include:
- Red, swollen, blistered, or peeling skin
- Skin irritation (with or without fever)
- Red or irritated eyes
- Sores in the mouth, throat, nose, or eyes
Other Possible Side Effects
Most people experience either no side effects or only mild side effects while taking this medication. However, if you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical help:
Headache
* Feeling dizzy, tired, or weak
This is not an exhaustive list of potential side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Severe dizziness or fainting
Slow heartbeat
Abnormal heartbeat that is new or worsening
Worsening heart failure (if you have a history of heart failure), characterized by:
+ Shortness of breath
+ Significant weight gain
+ Swelling in the arms or legs
Severe skin reactions, including:
+ Stevens-Johnson syndrome (SJS)
+ Toxic epidermal necrolysis (TEN)
+ Other severe skin reactions, which may be life-threatening
+ Signs of severe skin reactions include:
- Red, swollen, blistered, or peeling skin
- Skin irritation (with or without fever)
- Red or irritated eyes
- Sores in the mouth, throat, nose, or eyes
Other Possible Side Effects
Most people experience either no side effects or only mild side effects while taking this medication. However, if you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical help:
Headache
* Feeling dizzy, tired, or weak
This is not an exhaustive list of potential side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or fainting
- Very slow heart rate (e.g., less than 50 beats per minute)
- Swelling in your ankles or feet that is new or worsening
- Shortness of breath, especially with exertion or lying down
- Unusual tiredness or weakness
- Yellowing of the skin or eyes (jaundice)
- Dark urine or persistent nausea/vomiting (signs of liver problems)
- Chest pain that worsens or does not go away
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced.
Certain types of abnormal heart rhythms, as this medication is not suitable for individuals with specific heart rhythm disorders. If you are unsure, consult your doctor or pharmacist for guidance.
Existing health conditions, including:
+ Fluid accumulation in the lungs
+ Low blood pressure
+ Recent heart attack
Current medications, particularly:
+ Ivabradine
+ Rifampin
Please note that this is not an exhaustive list of all potential interactions. It is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health issues with your doctor and pharmacist to ensure safe use. Before starting, stopping, or modifying the dose of any medication, always consult your doctor to confirm it is safe to do so.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced.
Certain types of abnormal heart rhythms, as this medication is not suitable for individuals with specific heart rhythm disorders. If you are unsure, consult your doctor or pharmacist for guidance.
Existing health conditions, including:
+ Fluid accumulation in the lungs
+ Low blood pressure
+ Recent heart attack
Current medications, particularly:
+ Ivabradine
+ Rifampin
Please note that this is not an exhaustive list of all potential interactions. It is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health issues with your doctor and pharmacist to ensure safe use. Before starting, stopping, or modifying the dose of any medication, always consult your doctor to confirm it is safe to do so.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
When starting this medication, be cautious when performing tasks that require alertness, such as driving, until you understand how it affects you. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying position, and exercise caution when navigating stairs.
As directed by your doctor, regularly monitor your blood pressure and heart rate. You may need to undergo an electrocardiogram (ECG) before initiating this medication and during treatment. Discuss any concerns with your doctor.
If you have high blood pressure and are taking this medication, consult your doctor before using over-the-counter (OTC) products that may increase blood pressure, such as cough or cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and certain natural products or aids.
If you consume grapefruit juice or eat grapefruit regularly, discuss this with your doctor, as it may interact with your medication. Additionally, you may need to avoid consuming alcohol while taking this medication; consult your doctor or pharmacist for guidance.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
It is crucial to inform your doctor if you are pregnant, planning to become pregnant, or are breastfeeding. Your doctor will help you weigh the benefits and risks of this medication for both you and your baby.
When starting this medication, be cautious when performing tasks that require alertness, such as driving, until you understand how it affects you. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying position, and exercise caution when navigating stairs.
As directed by your doctor, regularly monitor your blood pressure and heart rate. You may need to undergo an electrocardiogram (ECG) before initiating this medication and during treatment. Discuss any concerns with your doctor.
If you have high blood pressure and are taking this medication, consult your doctor before using over-the-counter (OTC) products that may increase blood pressure, such as cough or cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and certain natural products or aids.
If you consume grapefruit juice or eat grapefruit regularly, discuss this with your doctor, as it may interact with your medication. Additionally, you may need to avoid consuming alcohol while taking this medication; consult your doctor or pharmacist for guidance.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
It is crucial to inform your doctor if you are pregnant, planning to become pregnant, or are breastfeeding. Your doctor will help you weigh the benefits and risks of this medication for both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe hypotension (very low blood pressure)
- Profound bradycardia (extremely slow heart rate)
- High-degree AV block (heart block)
- Asystole (cardiac arrest)
- Cardiogenic shock
- Dizziness, confusion, stupor, coma
What to Do:
Seek immediate medical attention. Call 911 or your local emergency number. For poison control, call 1-800-222-1222. Treatment may involve supportive care, IV fluids, atropine, calcium gluconate, vasopressors, or glucagon.
Drug Interactions
Contraindicated Interactions
- Ivabradine (risk of severe bradycardia)
- Dantrolene (IV) (risk of cardiovascular collapse)
Major Interactions
- Beta-blockers (additive negative chronotropic and inotropic effects, risk of severe bradycardia, AV block, heart failure)
- Digoxin (increased digoxin levels, risk of toxicity)
- Amiodarone (risk of severe bradycardia, AV block, hypotension)
- Statins (e.g., simvastatin, lovastatin - increased statin levels, risk of myopathy/rhabdomyolysis due to CYP3A4 inhibition)
- Fentanyl (increased fentanyl levels, risk of respiratory depression)
- Midazolam, Triazolam (increased benzodiazepine levels, prolonged sedation)
- Cyclosporine, Tacrolimus, Sirolimus (increased immunosuppressant levels, risk of toxicity)
- Alpha-blockers (e.g., prazosin - increased risk of hypotension)
- Clonidine (risk of severe bradycardia, AV block)
Moderate Interactions
- Other antihypertensives (additive hypotensive effects)
- Grapefruit juice (increased diltiazem levels)
- Carbamazepine (increased carbamazepine levels)
- Phenytoin (increased phenytoin levels)
- Rifampin, Phenobarbital (decreased diltiazem levels due to CYP3A4 induction)
- Cimetidine (increased diltiazem levels)
- Theophylline (increased theophylline levels)
Minor Interactions
- NSAIDs (may reduce antihypertensive effect)
- Alcohol (additive hypotensive effects)
Monitoring
Baseline Monitoring
Blood Pressure (BP)
Rationale: To establish baseline and assess efficacy for hypertension/angina.
Timing: Prior to initiation
Heart Rate (HR)
Rationale: To establish baseline and monitor for bradycardia.
Timing: Prior to initiation
Electrocardiogram (ECG)
Rationale: To assess baseline cardiac rhythm and PR interval, especially if pre-existing conduction abnormalities.
Timing: Prior to initiation
Liver Function Tests (LFTs)
Rationale: Diltiazem is extensively metabolized by the liver; baseline assessment is prudent, especially in patients with suspected hepatic impairment.
Timing: Prior to initiation
Renal Function (SCr, BUN)
Rationale: To assess baseline renal function, as metabolites are renally excreted.
Timing: Prior to initiation
Routine Monitoring
Blood Pressure (BP)
Frequency: Regularly, especially during dose titration and periodically thereafter (e.g., monthly until stable, then every 3-6 months)
Target: <130/80 mmHg (or individualized target)
Action Threshold: If BP remains uncontrolled or if symptomatic hypotension occurs.
Heart Rate (HR)
Frequency: Regularly, especially during dose titration and periodically thereafter (e.g., monthly until stable, then every 3-6 months)
Target: 50-90 bpm (or individualized target)
Action Threshold: If HR <50 bpm or symptomatic bradycardia occurs.
Signs/Symptoms of Edema
Frequency: Periodically
Target: Absence of significant peripheral edema
Action Threshold: Development of significant or bothersome peripheral edema.
ECG (PR interval)
Frequency: Periodically, especially with dose increases or co-administration of other AV nodal blocking agents.
Target: Normal PR interval (<0.20 seconds)
Action Threshold: Significant prolongation of PR interval or development of higher-degree AV block.
Liver Function Tests (LFTs)
Frequency: Periodically, especially if signs of hepatic dysfunction or with long-term therapy.
Target: Within normal limits
Action Threshold: Significant elevation of liver enzymes.
Symptom Monitoring
- Dizziness
- Lightheadedness
- Fatigue
- Headache
- Peripheral edema (swelling of ankles/feet)
- Bradycardia (slow heart rate)
- Palpitations
- Shortness of breath
- Chest pain (if angina not controlled)
- Signs of liver dysfunction (e.g., jaundice, dark urine, persistent nausea/vomiting)
Special Patient Groups
Pregnancy
Diltiazem is Pregnancy Category C. Animal studies have shown adverse effects on the fetus, but there are no adequate and well-controlled studies in pregnant women. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
Potential for teratogenicity observed in animal studies (skeletal abnormalities, embryolethality at high doses).
Second Trimester:
Limited human data, but generally avoided unless clearly indicated.
Third Trimester:
May cause fetal bradycardia or hypotension. Use with caution, especially near term.
Lactation
Diltiazem is excreted into breast milk. The American Academy of Pediatrics considers diltiazem to be compatible with breastfeeding. However, monitor the infant for potential adverse effects such as bradycardia, hypotension, or sedation.
Infant Risk:
Low to moderate risk. Monitor for bradycardia, hypotension, and drowsiness in the infant. Consider alternative if infant is premature or has cardiac issues.
Pediatric Use
Safety and efficacy have not been established in pediatric patients. Use is generally not recommended unless specifically indicated for certain cardiac conditions under specialist supervision.
Geriatric Use
Use with caution in elderly patients, as they may be more sensitive to the hypotensive and bradycardic effects of diltiazem. Start with lower doses and titrate slowly, monitoring closely for adverse effects.
Clinical Information
Clinical Pearls
- Diltiazem CD is a once-daily formulation; emphasize the importance of taking it whole and not crushing or chewing.
- It is effective for both hypertension and chronic stable angina, and can also be used for rate control in atrial fibrillation/flutter.
- Always check heart rate and blood pressure before administering, especially in hospitalized patients or during dose adjustments.
- Be mindful of drug interactions, particularly with beta-blockers, digoxin, and CYP3A4 substrates (e.g., statins, immunosuppressants).
- Peripheral edema is a common side effect, often dose-dependent and more prominent in the lower extremities.
- Patients should be advised to avoid grapefruit juice due to potential for increased diltiazem levels.
- Withdrawal should be gradual, especially in patients with angina, to avoid rebound angina.
Alternative Therapies
- Other Calcium Channel Blockers (e.g., Amlodipine, Verapamil, Nifedipine)
- Beta-blockers (e.g., Metoprolol, Atenolol)
- ACE Inhibitors (e.g., Lisinopril, Enalapril)
- Angiotensin Receptor Blockers (ARBs) (e.g., Valsartan, Losartan)
- Diuretics (e.g., Hydrochlorothiazide, Chlorthalidone)
- Nitrates (for angina)
- Digoxin (for rate control in AF)
Cost & Coverage
Average Cost:
Varies widely, typically $10-$50 per 30 capsules (300mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (for generic formulations)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it is a good idea to consult with your pharmacist. If you have any questions or concerns about this medication, do not hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.