Loading...
Loading...
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Cartia
Generic Name
Diltiazem Hydrochloride
Active Ingredient
DiltiazemCategory
Other
Salt Form
Hydrochloride
Variants
6
References used for this content
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Cartia, you must consult a qualified healthcare professional.
| 120 mg/1 | CAPSULE, EXTENDED RELEASE | ORAL | 62037-597 |
| 180 mg/1 | CAPSULE, EXTENDED RELEASE | ORAL | 71335-0879 |
| 120 mg/1 | CAPSULE, EXTENDED RELEASE | ORAL | 63629-7896 |
Detailed information about Cartia
Diltiazem is a non-dihydropyridine calcium channel blocker used to manage hypertension, chronic stable angina, and certain atrial arrhythmias by relaxing vascular smooth muscle and slowing cardiac conduction.
Dosage for Diltiazem must be highly individualized based on the patient's clinical response, heart rate, and blood pressure. According to clinical guidelines, the following are standard ranges:
The safety and effectiveness of Diltiazem in pediatric patients have not been established through large-scale clinical trials. Consequently, Diltiazem is generally not recommended for use in children. If a pediatric cardiologist determines that Diltiazem is necessary for a specific condition (such as certain types of supraventricular tachycardia), the dose will be strictly calculated based on the child's weight and closely monitored in a clinical setting.
While Diltiazem is primarily metabolized by the liver, its metabolites are excreted by the kidneys. In patients with significantly impaired renal function, healthcare providers should exercise caution and monitor the patient closely for signs of bradycardia (slow heart rate) or excessive hypotension (low blood pressure).
Since the liver is the primary site of Diltiazem metabolism, patients with liver cirrhosis or hepatic insufficiency may experience higher plasma concentrations and a longer half-life of the drug. Dose titration should be performed slowly and with extreme caution in this population.
Clinical studies suggest that elderly patients may have a higher risk of side effects due to age-related declines in liver and kidney function. Healthcare providers typically start elderly patients on the lowest possible dose and monitor blood pressure and heart rate frequently during the titration phase.
If you miss a dose of Diltiazem, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Never double the dose to 'catch up,' as this significantly increases the risk of heart block or severe hypotension.
An overdose of Diltiazem is a medical emergency. Symptoms may include extreme bradycardia (very slow heart rate), high-grade AV block, severe hypotension, dizziness, fainting, and heart failure. If an overdose is suspected, contact emergency services (911) or a poison control center immediately. Treatment usually involves gastric lavage, administration of activated charcoal, and intravenous support with calcium, vasopressors, or temporary pacing.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or stop taking this medication without medical guidance, as sudden discontinuation can lead to a rapid increase in blood pressure or a 'rebound' angina attack.
Many patients taking Diltiazem experience mild side effects as their bodies adjust to the medication. The most frequently reported include:
Diltiazem is a powerful cardiovascular medication that requires careful monitoring. Patients must be aware that while Diltiazem effectively manages symptoms of hypertension and angina, it is not a cure. It must be taken consistently, and patients should not stop the medication abruptly. Abrupt withdrawal can lead to a 'rebound' effect, characterized by severe chest pain (angina) or a dangerous spike in blood pressure.
As of 2026, there are no FDA black box warnings for Diltiazem. It is considered a safe and effective medication when used according to professional guidelines and in the absence of specific contraindications.
Certain medications must never be taken with Diltiazem due to the risk of life-threatening interactions:
There are several clinical scenarios where Diltiazem must NEVER be used because the risks far outweigh any potential benefits:
Diltiazem is traditionally classified as FDA Pregnancy Category C. This means that animal studies have shown adverse effects on the fetus (such as skeletal abnormalities and embryo toxicity), but there are no adequate, well-controlled studies in humans. Diltiazem should only be used during pregnancy if the potential benefit to the mother justifies the potential risk to the fetus. It is generally not the first-line choice for hypertension in pregnancy; agents like labetalol or nifedipine are often preferred. If you become pregnant while taking Diltiazem, notify your healthcare provider immediately.
Diltiazem is excreted in human breast milk. One study reported that the concentration in breast milk is nearly equal to the concentration in the mother's blood. Because of the potential for serious adverse reactions in nursing infants (such as bradycardia or hypotension), a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
The safety and effectiveness of Diltiazem in children have not been established. Its use in the pediatric population is rare and is typically limited to specialized cardiac care for specific arrhythmias under the strict supervision of a pediatric cardiologist. It is NOT approved for the treatment of hypertension in children.
Diltiazem is a calcium ion influx inhibitor (slow channel blocker or calcium antagonist). It inhibits the 'slow' inward current of calcium ions during the depolarization of cardiac muscle and vascular smooth muscle. By binding to the alpha-1 subunit of the L-type calcium channel, it prevents the opening of the channel, thereby reducing the amount of calcium that enters the cell. In vascular smooth muscle, this leads to relaxation and vasodilation, which lowers systemic blood pressure and increases coronary blood flow. In the heart, it acts on the SA and AV nodes to slow the heart rate and delay conduction, which is useful in treating supraventricular arrhythmias.
The onset of action for immediate-release Diltiazem is approximately 30 to 60 minutes, with peak effects occurring within 2 to 3 hours. For extended-release formulations, the peak effect is usually reached between 6 and 14 hours. The duration of effect for a single immediate-release dose is about 6 to 8 hours, whereas extended-release forms provide 24-hour coverage. Diltiazem produces a dose-dependent increase in the PR interval on an EKG, reflecting its effect on the AV node.
| Parameter | Value |
Common questions about Cartia
Diltiazem is primarily used to treat hypertension (high blood pressure) and to manage various forms of angina (chest pain), including chronic stable angina and vasospastic angina. Additionally, it is prescribed to control the heart rate in patients with certain atrial arrhythmias, such as atrial fibrillation and atrial flutter. By relaxing the blood vessels and slowing the heart's electrical conduction, it helps the heart pump more efficiently and reduces the risk of cardiovascular events. Some doctors may also use it off-label for conditions like Raynaud's phenomenon or to prevent migraines. Always take Diltiazem exactly as prescribed by your healthcare professional for your specific condition.
The most common side effects associated with Diltiazem include swelling of the ankles and feet (peripheral edema), headache, dizziness, and a feeling of tiredness or weakness. Some patients may also experience nausea, skin flushing, or a slow heart rate (bradycardia). Most of these side effects are mild and may improve as your body adjusts to the medication over several days or weeks. However, if the swelling becomes severe or if you feel extremely lightheaded, you should contact your doctor. It is also important to maintain good dental hygiene, as Diltiazem can occasionally cause gum overgrowth. Your healthcare provider can help manage these side effects by adjusting your dosage.
It is generally advised to avoid or significantly limit alcohol consumption while taking Diltiazem. Alcohol can enhance the blood-pressure-lowering effects of the medication, which may lead to severe dizziness, lightheadedness, or even fainting when you stand up. Additionally, alcohol can interfere with the way some extended-release versions of Diltiazem are released into your body, potentially causing too much medication to enter your bloodstream at once. This interaction can increase the risk of serious side effects like an dangerously slow heart rate. If you choose to drink, discuss it with your doctor to understand the specific risks based on your health profile. Safety is the priority when combining cardiovascular medications with alcohol.
Diltiazem is generally not recommended during pregnancy unless the potential benefits to the mother outweigh the potential risks to the fetus. It is classified as Pregnancy Category C, meaning animal studies have shown some harm to the developing fetus, but there isn't enough data from human studies to confirm its safety. Healthcare providers typically prefer other antihypertensive medications that have a more established safety record during pregnancy, such as labetalol or nifedipine. If you are planning to become pregnant or find out you are pregnant while taking Diltiazem, you must contact your doctor immediately. They will help you weigh the risks and transition you to a safer alternative if necessary. Never stop taking your blood pressure medication without medical supervision.
The time it takes for Diltiazem to work depends on the formulation you are taking and the condition being treated. For immediate-release tablets, you may begin to see a reduction in blood pressure or heart rate within 30 to 60 minutes of taking a dose. However, for extended-release capsules used for hypertension, it may take 1 to 2 weeks of consistent daily use to see the full blood-pressure-lowering effect. If you are taking it for angina, you might notice a decrease in the frequency of chest pain attacks within a few days. It is important to continue taking the medication even if you do not feel an immediate difference. Your doctor will likely monitor your progress over several weeks before deciding if a dose adjustment is needed.
No, you should never stop taking Diltiazem suddenly without first consulting your healthcare provider. Abruptly discontinuing this medication can lead to a 'rebound effect,' where your blood pressure spikes rapidly or your chest pain (angina) becomes much more frequent and severe. In some cases, sudden withdrawal can even trigger a heart attack in patients with underlying coronary artery disease. If your doctor decides that you should no longer take Diltiazem, they will provide you with a schedule to gradually reduce your dose over several days or weeks. This tapering process allows your body to adjust safely. Always ensure you have enough refills so you do not run out of medication unexpectedly.
If you miss a dose of Diltiazem, take it as soon as you remember. However, if it is almost time for your next scheduled dose, you should skip the missed dose and simply take your next dose at the regular time. Do not take two doses at once to make up for the one you missed, as this can lead to a dangerously slow heart rate or very low blood pressure. If you find yourself frequently forgetting doses, consider using a pill organizer or setting a daily alarm on your phone. Consistency is key to managing blood pressure and heart rhythm effectively. If you miss more than one dose in a row, contact your healthcare provider for further instructions.
Diltiazem does not typically cause weight gain in the form of increased body fat. However, it is a very common cause of peripheral edema, which is fluid retention that results in swelling of the ankles, feet, and legs. This fluid buildup can cause a noticeable increase on the scale, sometimes several pounds over just a few days. If you notice a sudden, significant increase in weight (such as more than 3 pounds in 24 hours), it could be a sign that your body is retaining too much fluid or that your heart is under stress. You should report any rapid weight gain or new swelling to your doctor immediately. They can determine if the weight gain is due to the medication or another underlying issue.
Diltiazem can interact with many other medications, so it is vital to provide your doctor with a complete list of everything you take. It is particularly known to interact with other heart medications like beta-blockers and digoxin, which can cause your heart rate to slow down too much. It also interacts with certain cholesterol-lowering statins, such as simvastatin, increasing the risk of muscle damage. Other drugs like grapefruit juice, certain antibiotics, and even herbal supplements like St. John's Wort can change how Diltiazem works in your body. Your pharmacist can check for these interactions to ensure your combination of medications is safe. Never start a new over-the-counter drug or supplement without checking with a professional first.
Yes, Diltiazem is widely available as a generic medication in many different forms, including immediate-release tablets and various extended-release capsules. Generic versions are typically much more affordable than brand-name versions like Cardizem, Tiazac, or Dilacor XR. However, it is important to note that different generic versions of extended-release Diltiazem may not be exactly the same. Some are designed to be taken once a day, while others are taken twice a day, and their release mechanisms can vary. For this reason, once you start a specific generic version that works for you, it is often best to stay with that same manufacturer. Always check with your pharmacist if the appearance of your medication changes.
Other drugs with the same active ingredient (Diltiazem)
These effects may occur in a smaller percentage of patients and should be discussed with a doctor if they persist:
Rare but documented side effects include:
> Warning: Stop taking Diltiazem and call your doctor or emergency services immediately if you experience any of the following:
With prolonged use, some patients may develop chronic peripheral edema that requires management with lifestyle changes or dose adjustment. Gingival hyperplasia (gum overgrowth) is also more likely with long-term therapy and may require professional dental intervention. There is no evidence that Diltiazem causes long-term cognitive decline or significant metabolic changes, but regular monitoring of blood pressure and heart rhythm is necessary for the duration of therapy.
There are currently no FDA black box warnings for Diltiazem. However, it carries significant warnings regarding its use in patients with specific heart conditions, such as Sick Sinus Syndrome or second- or third-degree AV block, as it can cause fatal heart rhythm disturbances in these populations.
Report any unusual symptoms to your healthcare provider. Even mild side effects should be monitored to ensure they do not progress into more serious complications.
Patients taking Diltiazem should undergo regular clinical evaluations, which may include:
Diltiazem can cause dizziness, lightheadedness, or fatigue, especially during the first few weeks of treatment or after a dose increase. Do not drive, operate heavy machinery, or engage in potentially dangerous activities until you know how this medication affects you.
Alcohol should be avoided or strictly limited while taking Diltiazem. Alcohol can enhance the blood-pressure-lowering effects of Diltiazem, leading to severe dizziness, fainting, or a dangerously slow heart rate. Furthermore, some extended-release formulations may release the drug too quickly into the bloodstream when combined with alcohol (a phenomenon known as 'dose dumping').
If Diltiazem needs to be stopped, it should be done under a doctor's supervision. Typically, the dose is gradually reduced (tapered) over several days or weeks to prevent rebound hypertension or worsening of angina symptoms.
> Important: Discuss all your medical conditions, especially any history of heart, liver, or kidney disease, with your healthcare provider before starting Diltiazem.
Diltiazem is not known to significantly interfere with most common laboratory tests. However, it can occasionally cause transient elevations in liver function tests (AST, ALT) or alkaline phosphatase.
For each major interaction, the mechanism usually involves the CYP3A4 enzyme pathway (where Diltiazem acts as a moderate inhibitor) or an additive pharmacodynamic effect (where two drugs both slow the heart rate). Management typically involves dose reduction of the interacting drug or more frequent clinical monitoring.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, including over-the-counter pain relievers and cold medications.
In these cases, a healthcare provider must perform a careful risk-benefit analysis before prescribing Diltiazem:
While Diltiazem is a benzothiazepine, patients who have had severe allergic reactions to other calcium channel blockers (like verapamil or amlodipine) should be monitored closely, although there is no definitive evidence of broad cross-reactivity across different classes of CCBs.
> Important: Your healthcare provider will evaluate your complete medical history, including EKG results and current heart function, before determining if Diltiazem is safe for you.
Clinical trials of Diltiazem did not include sufficient numbers of subjects aged 65 and over to determine if they respond differently than younger subjects. However, clinical experience suggests that elderly patients are more susceptible to the side effects of Diltiazem, particularly peripheral edema, dizziness, and constipation. There is also a higher risk of drug-drug interactions due to polypharmacy (taking multiple medications). Healthcare providers usually start elderly patients at the lower end of the dosing range.
In patients with renal impairment, the pharmacokinetics of Diltiazem are not significantly altered, but the excretion of its metabolites may be delayed. No specific initial dose adjustment is usually required, but patients with a GFR (Glomerular Filtration Rate) below 30 mL/min should be monitored more frequently for signs of toxicity. Diltiazem is not removed by peritoneal dialysis or hemodialysis.
Since Diltiazem is extensively metabolized by the liver, patients with hepatic impairment (Child-Pugh Class B or C) will have higher blood levels of the drug. These patients require a lower starting dose and a slower titration schedule. Liver function should be monitored periodically during treatment.
> Important: Special populations require individualized medical assessment and more frequent follow-up with a healthcare provider.
|---|---|
| Bioavailability | ~40% (due to first-pass metabolism) |
| Protein Binding | 70% to 80% |
| Half-life | 3 to 4.5 hours (IR); 5 to 9 hours (ER) |
| Tmax | 2-3 hours (IR); 6-14 hours (ER) |
| Metabolism | Hepatic (CYP3A4, CYP2D6, CYP2C9) |
| Excretion | Renal (2-4% unchanged), Fecal (remainder) |
Diltiazem is classified as a Non-Dihydropyridine Calcium Channel Blocker. Within this class, it is the only member of the benzothiazepine family. It is related to verapamil (a phenylalkylamine) in its cardiac effects, but it generally has a less potent negative inotropic effect, making it slightly better tolerated in some patients with mild heart dysfunction.