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Diltiazem ER 300mg Tablets (la 24h)

Manufacturer OCEANSIDE PHARMACEUTICALS Active Ingredient Diltiazem Long-Acting Tablets(dil TYE a zem) Pronunciation dil TYE a zem
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.
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Drug Class
Antihypertensive, Antianginal, Antiarrhythmic
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Pharmacologic Class
Calcium Channel Blocker (Non-dihydropyridine)
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Pregnancy Category
Category C
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FDA Approved
Sep 1982
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DEA Schedule
Not Controlled

Overview

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What is this medicine?

Diltiazem is a medication that helps relax blood vessels and slow down your heart rate. It's used to treat high blood pressure, chest pain (angina), and certain irregular heart rhythms. The extended-release (ER) form is taken once a day.
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How to Use This Medicine

Taking Your Medication Correctly

To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely.

Take your medication as directed by your doctor, swallowing the tablets whole without chewing, breaking, or crushing them.
 Establish a routine by taking your medication at the same time every day.
Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start feeling well.

Storing and Disposing of Your Medication

To maintain the effectiveness and safety of your medication:

 Store it at room temperature, protected from light and moisture. Avoid storing it in a bathroom.
Keep your medication in a safe and secure location, out of the reach of children and pets.
 Dispose of unused or expired medication properly. Do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist or healthcare provider. Check with your pharmacist for guidance on the best disposal method, and consider participating in local drug take-back programs.

What to Do If You Miss a Dose

If you miss a dose of your medication:

Take it as soon as you remember, unless it's close to the time for your next scheduled dose.
 If it's almost time for your next dose, skip the missed dose and resume your regular dosing schedule.
* Do not take two doses at once or take extra doses to make up for a missed dose.
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Lifestyle & Tips

  • Take the medication exactly as prescribed, usually once daily. Do not crush, chew, or break extended-release tablets.
  • Swallow the tablet whole.
  • Do not stop taking this medication suddenly without consulting your doctor, as it can worsen your condition.
  • Avoid grapefruit and grapefruit juice, as they can increase the levels of diltiazem in your body.
  • Limit alcohol consumption, as it can increase the hypotensive effects.
  • Maintain a healthy diet (e.g., low sodium, low fat) and engage in regular exercise as advised by your doctor.
  • Monitor your blood pressure and heart rate at home if advised by your doctor.
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Available Forms & Alternatives

Available Strengths:

Dosing & Administration

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Adult Dosing

Standard Dose: 300 mg orally once daily (extended-release)
Dose Range: 120 - 480 mg

Condition-Specific Dosing:

hypertension: Initial: 180-240 mg once daily; Titrate up to 300-480 mg once daily based on response.
chronicStableAngina: Initial: 120-180 mg once daily; Titrate up to 300-480 mg once daily based on response.
atrialFibrillationFlutter: Initial: 120-240 mg once daily; Titrate up to 360-480 mg once daily for heart rate control.
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Pediatric Dosing

Neonatal: Not established
Infant: Not established
Child: Not established
Adolescent: Not established (Safety and efficacy not established in pediatric patients)
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Dose Adjustments

Renal Impairment:

Mild: No specific dose adjustment generally required.
Moderate: Use with caution; monitor for exaggerated effects. Dose adjustment may be necessary.
Severe: Use with caution; monitor for exaggerated effects. Dose adjustment may be necessary.
Dialysis: Diltiazem is not significantly removed by hemodialysis. Use with caution and monitor.

Hepatic Impairment:

Mild: Use with caution; monitor for exaggerated effects.
Moderate: Reduced clearance may occur. Initiate at lower doses and titrate slowly with careful monitoring.
Severe: Reduced clearance may occur. Initiate at lower doses and titrate slowly with careful monitoring. Contraindicated in severe hepatic dysfunction for some formulations.

Pharmacology

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Mechanism of Action

Diltiazem is a non-dihydropyridine calcium channel blocker. It 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 afterload. In the heart, it decreases sinoatrial (SA) and atrioventricular (AV) nodal conduction, prolonging the effective refractory period and slowing heart rate. It also reduces myocardial contractility.
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Pharmacokinetics

Absorption:

Bioavailability: Approximately 40-65% (due to extensive first-pass metabolism)
Tmax: 5-9 hours (for extended-release formulations)
FoodEffect: Food may increase bioavailability slightly but is generally not clinically significant for ER formulations; can be taken with or without food.

Distribution:

Vd: 3-13 L/kg
ProteinBinding: 70-80%
CnssPenetration: Limited

Elimination:

HalfLife: 5-10 hours (for extended-release formulations)
Clearance: Not available
ExcretionRoute: Renal (approximately 60-65% as metabolites), Fecal (approximately 35% as metabolites)
Unchanged: Less than 4% (renal)
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Pharmacodynamics

OnsetOfAction: Within 30-60 minutes (for ER formulations)
PeakEffect: 5-9 hours (for ER formulations)
DurationOfAction: 24 hours (for ER formulations)

Safety & Warnings

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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
New or worsening abnormal heartbeat
 Worsening heart failure (if you have a history of heart failure, consult your doctor). Seek immediate medical attention if you experience:
+ Shortness of breath
+ Sudden weight gain
+ Swelling in the arms or legs
Severe skin reactions, including:
+ Stevens-Johnson syndrome (SJS)
+ Toxic epidermal necrolysis (TEN)
+ Other severe skin reactions (sometimes fatal). Seek medical help right away if you notice:
+ Red, swollen, blistered, or peeling skin
+ Other skin irritation (with or without fever)
+ Red or irritated eyes
+ Sores in your mouth, throat, nose, or eyes

Other Possible Side Effects

Like all medications, this drug can cause side effects. Many people may not experience any side effects or only minor ones. If you are bothered by any of the following side effects or if they persist, contact your doctor or seek medical help:

 Headache
* Feeling dizzy, tired, or weak

This is not an exhaustive list of possible 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.
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Seek Immediate Medical Attention If You Experience:

  • Severe dizziness or fainting
  • Very slow heart rate (e.g., less than 50 beats per minute)
  • Shortness of breath, especially with exertion or lying down
  • New or worsening swelling in your ankles or feet
  • Chest pain that worsens or does not go away
  • Signs of liver problems (e.g., yellowing of skin/eyes, dark urine, persistent nausea/vomiting, unusual tiredness)
  • Severe headache that is unusual or persistent
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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 use with many types of irregular heartbeats. If you are unsure, consult your doctor or pharmacist.
Specific health conditions, including:
+ Fluid accumulation in the lungs
+ Low blood pressure
+ Recent heart attack
 If you are currently taking any of the following medications:
+ 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. Never start, stop, or adjust the dosage of any medication without first consulting your doctor to confirm it is safe to do so with this medication.
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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, avoid driving and other activities that require alertness until you understand how it affects you. To minimize the risk of dizziness or fainting, stand up slowly after sitting or lying down, and exercise caution when climbing stairs.

Follow your doctor's instructions for monitoring 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 regularly consume grapefruit juice or eat grapefruit, discuss this with your doctor. Additionally, talk to your doctor before consuming alcohol while taking this medication.

If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.

If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor. You will need to discuss the potential benefits and risks of this medication to both you and your baby.
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Overdose Information

Overdose Symptoms:

  • Severe hypotension (very low blood pressure)
  • Profound bradycardia (extremely slow heart rate)
  • Asystole (cardiac arrest)
  • High-degree AV block
  • Cardiogenic shock
  • Congestive heart failure
  • 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 gastric lavage, activated charcoal, IV fluids, atropine, calcium gluconate, vasopressors, and/or glucagon.

Drug Interactions

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Contraindicated Interactions

  • Ivabradine (risk of excessive bradycardia)
  • Dantrolene (IV) (risk of cardiovascular collapse)
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Major Interactions

  • Beta-blockers (e.g., metoprolol, propranolol) - increased risk of bradycardia, AV block, heart failure
  • Digoxin - increased digoxin levels, increased risk of bradycardia/AV block
  • Amiodarone - increased risk of bradycardia, AV block, hypotension
  • Statins (e.g., simvastatin, lovastatin) - increased statin levels, increased risk of myopathy/rhabdomyolysis
  • Cyclosporine - increased cyclosporine levels
  • Tacrolimus - increased tacrolimus levels
  • Carbamazepine - increased carbamazepine levels
  • Phenytoin - increased phenytoin levels
  • Rifampin (and other strong CYP3A4 inducers) - decreased diltiazem levels
  • Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, ritonavir) - increased diltiazem levels
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Moderate Interactions

  • Alpha-blockers (e.g., prazosin, doxazosin) - increased risk of hypotension
  • Nitrates - additive hypotensive effects
  • Fentanyl - increased fentanyl levels
  • Buspirone - increased buspirone levels
  • Midazolam/Triazolam - increased benzodiazepine levels
  • Theophylline - increased theophylline levels
  • Cimetidine - increased diltiazem levels
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Minor Interactions

Monitoring

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Baseline Monitoring

Blood Pressure (BP)

Rationale: To establish baseline and guide initial dosing for hypertension/angina.

Timing: Prior to initiation

Heart Rate (HR)

Rationale: To establish baseline and assess risk of 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: To assess baseline hepatic function, as diltiazem is extensively metabolized by the liver.

Timing: Prior to initiation, especially in patients with suspected hepatic impairment

Renal Function Tests (e.g., SCr, BUN)

Rationale: To assess baseline renal function, as metabolites are renally excreted.

Timing: Prior to initiation, especially in patients with suspected renal impairment

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Routine Monitoring

Blood Pressure (BP)

Frequency: Regularly, especially during dose titration and periodically thereafter (e.g., weekly during titration, then monthly/quarterly)

Target: Individualized based on condition (e.g., <130/80 mmHg for hypertension)

Action Threshold: Persistent hypotension (e.g., SBP <90 mmHg or symptomatic), or inadequate BP control

Heart Rate (HR)

Frequency: Regularly, especially during dose titration and periodically thereafter (e.g., weekly during titration, then monthly/quarterly)

Target: Typically >50-60 bpm (unless target for rate control is lower)

Action Threshold: Bradycardia (<50 bpm or symptomatic), or inadequate HR control for arrhythmias

Electrocardiogram (ECG)

Frequency: Periodically, or if symptoms of bradycardia, AV block, or other arrhythmias develop

Target: Normal sinus rhythm, PR interval <0.20 seconds (unless target for rate control is lower)

Action Threshold: Significant bradycardia, new or worsening AV block (e.g., 2nd or 3rd degree), or other conduction abnormalities

Liver Function Tests (LFTs)

Frequency: Periodically, especially in patients with pre-existing hepatic impairment or if symptoms of liver dysfunction develop

Target: Within normal limits

Action Threshold: Significant elevation of liver enzymes (e.g., >3x ULN)

Symptoms of peripheral edema

Frequency: At each visit

Target: Absence of significant edema

Action Threshold: New or worsening peripheral edema

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Symptom Monitoring

  • Dizziness
  • Lightheadedness
  • Fatigue
  • Bradycardia (slow heart rate)
  • Palpitations
  • Shortness of breath
  • Swelling in ankles/feet (edema)
  • Headache
  • Nausea
  • Constipation
  • Signs of liver dysfunction (e.g., jaundice, dark urine, persistent nausea/vomiting)

Special Patient Groups

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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).
Second Trimester: Potential for fetal bradycardia and other cardiovascular effects.
Third Trimester: Potential for fetal bradycardia and other cardiovascular effects; may inhibit labor.
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Lactation

Diltiazem is excreted in human breast milk. The American Academy of Pediatrics considers it compatible with breastfeeding, but caution is advised. Monitor the infant for bradycardia, hypotension, and sedation.

Infant Risk: L3 (Moderately Safe) - Monitor infant for adverse effects, especially bradycardia and hypotension. Consider alternative if infant is premature or has cardiac issues.
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Pediatric Use

Safety and efficacy have not been established in pediatric patients. Use is generally not recommended.

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Geriatric Use

Use with caution in elderly patients, as they may be more sensitive to the hypotensive and bradycardic effects. Start with lower doses and titrate slowly. Monitor renal and hepatic function.

Clinical Information

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Clinical Pearls

  • Diltiazem ER should be swallowed whole; crushing or chewing can lead to rapid release and potential overdose.
  • Avoid grapefruit juice due to significant CYP3A4 interaction.
  • Monitor heart rate and blood pressure closely, especially when initiating therapy or titrating dose, and when combining with other rate-lowering agents (e.g., beta-blockers, digoxin).
  • Peripheral edema is a common side effect, often dose-dependent, and may be managed with diuretics or by reducing the dose.
  • Diltiazem is a non-dihydropyridine CCB, distinguishing its cardiac effects (rate and conduction) from dihydropyridines (e.g., amlodipine, nifedipine) which primarily cause vasodilation.
  • Patients with sick sinus syndrome or second/third-degree AV block without a pacemaker should generally not receive diltiazem due to risk of severe bradycardia or asystole.
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Alternative Therapies

  • Other Calcium Channel Blockers (e.g., Verapamil for rate control/angina, Amlodipine/Nifedipine for hypertension/angina)
  • Beta-blockers (e.g., Metoprolol, Atenolol, Carvedilol for hypertension, angina, rate control)
  • ACE Inhibitors (e.g., Lisinopril, Enalapril for hypertension, heart failure)
  • Angiotensin Receptor Blockers (ARBs) (e.g., Valsartan, Losartan for hypertension, heart failure)
  • Diuretics (e.g., Hydrochlorothiazide, Furosemide for hypertension, edema)
  • Nitrates (e.g., Isosorbide mononitrate, Nitroglycerin for angina)
  • Antiarrhythmics (e.g., Amiodarone, Flecainide for atrial fibrillation/flutter)
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Cost & Coverage

Average Cost: Varies widely, typically $30-$150 per 30 tablets
Generic Available: Yes
Insurance Coverage: Tier 1 or Tier 2 (Generic)
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General Drug Facts

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.