Medicine Information

Diltiazem

Name: Diltiazem
Brand: Diltiazem
Rating: 4.5 (117 reviews)

Tablet30 mgCalcium Channel Blocker, Antiarrhythmic, AntihypertensiveATC: C08DA01

Generic Name

diltiazem-30-mg-tablet

Manufacturer

Multiple manufacturers

Country

Global

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Price Details

Current market pricing information

Variant	Unit Price	Strip Price
diltiazem 30 mg tablet	৳ 2.00	৳ 20.00

Description

Overview of the medicine

Diltiazem is a calcium channel blocker used to treat high blood pressure (hypertension), angina (chest pain), and certain heart rhythm disorders like atrial fibrillation or flutter.

Uses & Indications

Management of chronic stable angina (classic effort-associated angina)

Management of vasospastic angina (Prinzmetal's or variant angina)

Management of mild to moderate hypertension, alone or in combination with other antihypertensive agents

Rate control in atrial fibrillation or atrial flutter

Dosage

Adults

For angina: Initial dose of 30 mg four times daily, before meals and at bedtime. Dosage may be gradually increased at 1- to 2-day intervals until optimal response is achieved (usual therapeutic range is 180-360 mg/day). For hypertension: Initial dose 30 mg four times daily; adjust according to blood pressure response.

Elderly

Lower initial doses are often recommended, with careful titration due to potential for increased sensitivity and reduced drug clearance. Monitor closely for bradycardia and hypotension.

Renal_impairment

Use with caution. Although specific dosage adjustments are not routinely recommended, close monitoring of blood pressure and heart rate is advised. Dosage adjustment may be necessary in severe impairment.

How to Take

Take orally, with or without food. Swallow the tablet whole; do not crush, chew, or break.

Mechanism of Action

Diltiazem inhibits the influx of extracellular calcium ions across the membranes of myocardial and vascular smooth muscle cells. This action causes relaxation of vascular smooth muscle, resulting in vasodilation (especially coronary arteries) and a reduction in peripheral vascular resistance. It also slows AV nodal conduction and decreases myocardial contractility and heart rate.

Pharmacokinetics

Onset

Oral (immediate-release): 30-60 minutes.

Excretion

Approximately 60-65% is excreted in the urine and 35% in feces, mainly as metabolites.

Half life

Plasma elimination half-life is 3.5 to 9 hours.

Absorption

Well absorbed orally (80-90%), but undergoes extensive first-pass metabolism. Absolute bioavailability is approximately 40%.

Metabolism

Extensively metabolized in the liver, primarily by the cytochrome P450 3A4 (CYP3A4) enzyme system. Several metabolites are formed, with N-desmethyldiltiazem being active.

Side Effects

Contraindications

Sick sinus syndrome (unless a functional ventricular pacemaker is in place)
Second- or third-degree AV block (unless a functional ventricular pacemaker is in place)
Hypotension (systolic blood pressure <90 mmHg)
Acute myocardial infarction and pulmonary congestion
Known hypersensitivity to diltiazem

Drug Interactions

Digoxin

May increase digoxin serum levels. Monitor digoxin levels and adjust dose as necessary.

Amiodarone

Increased risk of bradycardia and AV block.

Beta-blockers

Increased risk of bradycardia, heart block, and myocardial depression. Use with caution and monitor cardiac function.

Grapefruit juice

Can increase diltiazem plasma concentrations due to CYP3A4 inhibition.

Statins (e.g., simvastatin, lovastatin)

Diltiazem inhibits CYP3A4, which can increase statin plasma concentrations, increasing risk of myopathy/rhabdomyolysis. Consider lower statin doses or alternative statins.

Storage

Store at controlled room temperature (15-30°C or 59-86°F). Protect from light and moisture. Keep out of reach of children.

Overdose

Overdose can lead to severe bradycardia, hypotension, heart block, and cardiac arrest. Management includes supportive care, gastric lavage/activated charcoal, and symptomatic treatment. Atropine, vasopressors (e.g., dopamine, norepinephrine), calcium gluconate, and temporary cardiac pacing may be required.

Pregnancy & Lactation

Pregnancy category C. Diltiazem should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Diltiazem is excreted in human breast milk; therefore, caution should be exercised when diltiazem is administered to a nursing woman, or consider an alternative therapy.

Frequently Asked Questions

Common questions about this medicine

Pack Sizes

10 tablets per strip (blister pack)30 tablets per box

Shelf Life

Typically 2 to 3 years from the date of manufacture when stored under recommended conditions.

Availability

Pharmacies, hospitals

Approval Status

Approved

Patent Status

Generic

WHO Essential Medicine

Yes

Clinical Trials

Diltiazem has been extensively studied in numerous clinical trials demonstrating its efficacy in reducing blood pressure, controlling angina symptoms, and managing heart rate in atrial fibrillation and flutter. Studies have also focused on its pharmacokinetic profile and drug interactions.

Lab Monitoring

Blood pressure monitoring (especially at initiation and dose changes)
Heart rate and ECG monitoring (especially in patients with conduction abnormalities)
Liver and kidney function tests (periodically, in prolonged therapy or pre-existing impairment)

Doctor Notes

Monitor patient for signs of bradycardia, hypotension, and heart failure, especially during initiation or dose titration.
Caution advised in patients with impaired left ventricular function or those receiving concomitant beta-blockers or digoxin.
Educate patients on the importance of avoiding grapefruit products due to potential drug interactions.
Consider extended-release formulations for better patient adherence and smoother blood pressure/heart rate control.

Patient Guidelines

Take your medication exactly as prescribed by your doctor; do not stop abruptly without consulting your doctor.
Report any new or worsening symptoms such as swelling, shortness of breath, severe dizziness, or fainting.
Avoid grapefruit and grapefruit juice while taking diltiazem.
Be aware that immediate-release tablets are taken multiple times a day, while extended-release forms are typically once daily.

Missed Dose Advice

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Driving Precautions

Diltiazem may cause dizziness or lightheadedness, especially when starting the medication or changing the dose. Patients should use caution when driving or operating machinery until they know how the medication affects them.

Lifestyle Advice

Maintain a heart-healthy diet low in sodium and saturated fats.
Engage in regular physical activity as advised by your doctor.
Avoid smoking and limit alcohol consumption to help manage blood pressure and overall heart health.
Manage stress through relaxation techniques or hobbies.