{"id":9018,"date":"2026-06-03T15:43:26","date_gmt":"2026-06-03T15:43:26","guid":{"rendered":"https:\/\/telyrx.com\/blog\/?p=9018"},"modified":"2026-06-03T15:43:43","modified_gmt":"2026-06-03T15:43:43","slug":"what-is-diltiazem-er-cd-capsules","status":"publish","type":"post","link":"https:\/\/telyrx.com\/blog\/medications\/what-is-diltiazem-er-cd-capsules\/","title":{"rendered":"What Is Diltiazem ER?"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\" id=\"h-how-it-works\">How It Works<\/h2>\n\n\n\n<p>Diltiazem belongs to a class of medications called non-dihydropyridine calcium channel blockers. It works by preventing calcium ions from entering the smooth muscle cells of the heart and blood vessels. This helps relax the blood vessels, lowering blood pressure and making it easier for the heart to pump blood throughout the body.<\/p>\n\n\n\n<div class=\"quick-facts-card\">\n  <table class=\"quick-facts-table\">\n    <colgroup>\n      <col\/>\n      <col\/>\n    <\/colgroup>\n\n    <thead>\n      <tr>\n        <th colspan=\"2\">Quick Facts<\/th>\n      <\/tr>\n    <\/thead>\n\n    <tbody>\n      <tr>\n        <td><strong>Common Brands<\/strong><\/td>\n        <td>Cardizem CD, Cardizem LA, Cartia XT, Dilacor XR, Matzim LA, Taztia XT, Tiadylt ER, Tiazac<\/td>\n      <\/tr>\n\n      <tr>\n         <td><strong>Drug Class<\/strong><\/td>\n        <td>Non-dihydropyridine calcium channel blocker<\/td>\n      <\/tr>\n\n      <tr>\n        <td><strong>Generic Status<\/strong><\/td>\n        <td>Generic is available<\/td>\n      <\/tr>\n\n      <tr>\n         <td><strong>Availability<\/strong><\/td>\n        <td>Prescription only<\/td>\n    <\/tbody>\n  <\/table>\n<\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-dosing\">Dosing<\/h2>\n\n\n\n<p>For the management of high blood pressure, providers typically recommend a starting dose of 120-240 mg of diltiazem ER, taken by mouth once or twice daily, depending on the specific extended-release product prescribed. Maintenance doses generally range from 120 mg to 540 mg daily to achieve blood pressure targets.&nbsp;<\/p>\n\n\n\n<p>When used for chest pain, the initial dose is often 120-180 mg once daily, with gradual adjustments based on the patient\u2019s response. Some formulations may be prescribed as a twice-daily regimen, starting at 60-120 mg per dose.<\/p>\n\n\n\n<p><em><strong>Note:<\/strong> Dosing information below is educational only. Your prescribing physician will determine your specific dose based on your individual health needs.\u00a0Always follow your healthcare provider\u2019s instructions for exact dosing.<\/em><\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-uses\">Uses<\/h2>\n\n\n\n<p><strong>FDA-Approved Uses<\/strong><\/p>\n\n\n\n<p>Diltiazem ER is FDA-approved to treat high blood pressure. It is also approved to manage certain types of chest pain, known as angina.<\/p>\n\n\n\n<p><strong>Off-Label Uses<\/strong><\/p>\n\n\n\n<p>You may see diltiazem ER prescribed for uses that are not &#8220;FDA-approved.&#8221; This is a common and legal practice called &#8220;off-label&#8221; prescribing, where a doctor uses their clinical judgment to prescribe a drug for a different (but well-researched) purpose.<\/p>\n\n\n\n<p>Diltiazem is sometimes prescribed off-label for rate control in abnormal heart rhythm, such as atrial fibrillation.<\/p>\n\n\n<div class=\"telyrx-email-cta telyrx-email-cta--banner alignfull wp-block-telyrx-email-signup\">\n\t\t<h2 class=\"telyrx-email-cta__heading\" data-toc-hidden=\"true\">Get Savings Updates<\/h2>\n\t<p class=\"telyrx-email-cta__description\">Join our mailing list for exclusive deals and more.<\/p>\n\t\t\t<form\n\t\t\tid=\"telyrx-email-form-1\"\n\t\t\tclass=\"telyrx-email-cta__form\"\n\t\t\tdata-portal-id=\"46401311\"\n\t\t\tdata-form-id=\"14e1d7d5-6b17-4228-b42e-c06d1a6c240b\"\n\t\t\tdata-i18n=\"{&quot;subscribe&quot;:&quot;Subscribe&quot;,&quot;success&quot;:&quot;Thanks! You&#039;re subscribed.&quot;,&quot;error&quot;:&quot;Something went wrong. Please try again.&quot;}\"\n\t\t>\n\t\t\t<div class=\"telyrx-email-cta__pill\">\n\t\t\t\t<input\n\t\t\t\t\ttype=\"email\"\n\t\t\t\t\tname=\"email\"\n\t\t\t\t\tclass=\"telyrx-email-cta__input\"\n\t\t\t\t\tplaceholder=\"Enter your email\"\n\t\t\t\t\trequired\n\t\t\t\t\tautocomplete=\"email\"\n\t\t\t\t\/>\n\t\t\t\t<button type=\"submit\" class=\"telyrx-email-cta__button\">\n\t\t\t\t\tSubscribe\t\t\t\t<\/button>\n\t\t\t<\/div>\n\t\t\t<p class=\"telyrx-email-cta__status\" aria-live=\"polite\"><\/p>\n\t\t<\/form>\n\t\t<noscript>\n\t\t\t<p class=\"telyrx-email-cta__noscript\">Please enable JavaScript to use the signup form.<\/p>\n\t\t<\/noscript>\n\t<\/div>\n\n\n\n<section class=\"telyrx-side-effects\" data-toc-title=\"Side Effects\">\n\t<h2 class=\"telyrx-side-effects__heading\">Side Effects<\/h2>\n\t<hr class=\"telyrx-side-effects__separator\">\n\t<div class=\"telyrx-side-effects__content\">\n\t\t\n\n<p>Like all medications, diltiazem ER can cause side effects. Some common side effects may improve over time as your body adjusts to the medication. Other side effects may be serious and require medical attention.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-common-side-effects\">Common Side Effects<\/h3>\n\n\n\n<div class=\"telyrx-side-effects-chip telyrx-side-effects-chip--common\">\n\t\n\n<ul class=\"wp-block-list\">\n<li>Headache<\/li>\n\n\n\n<li>Dizziness<\/li>\n\n\n\n<li>Fatigue<\/li>\n\n\n\n<li>Nausea<\/li>\n\n\n\n<li>Flushing or redness of the skin<\/li>\n\n\n\n<li>Constipation<\/li>\n\n\n\n<li>Fluid retention and swelling in the legs or feet<\/li>\n\n\n\n<li>Upset stomach or indigestion<\/li>\n\n\n\n<li>Sore throat<\/li>\n<\/ul>\n\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-serious-side-effects\">Serious Side Effects<\/h3>\n\n\n\n<div class=\"telyrx-side-effects-chip telyrx-side-effects-chip--serious\">\n\t\n\n<p>Serious side effects are rare, but it&#8217;s important to know what to look for if they do occur.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Heart rhythm changes<\/strong>: Diltiazem may cause an irregular heartbeat or a feeling of skipped heartbeats, which can occasionally lead to fainting.<\/li>\n\n\n\n<li><strong>Heart rate changes<\/strong>: This medication can slow the heart rate (bradycardia), which may lead to lightheadedness and fatigue.<\/li>\n\n\n\n<li><strong>Low blood pressure<\/strong>: Experiencing severely low blood pressure (hypotension) is possible when taking diltiazem ER. Low blood pressure may cause dizziness, confusion, or weakness.<\/li>\n\n\n\n<li><strong>Worsening heart failure<\/strong>: There is a risk of developing or worsening heart failure when taking diltiazem ER. This may cause symptoms such as shortness of breath, unusual weight gain, or severe swelling in the lower extremities.<\/li>\n\n\n\n<li><strong>Liver damage<\/strong>: Rare instances of liver toxicity can occur with diltiazem ER. Signs of liver damage can include right-sided stomach pain, severe nausea, or yellowing of the skin and eyes (jaundice).<\/li>\n\n\n\n<li><strong>Severe skin reactions<\/strong>: Life-threatening skin conditions, such as Stevens-Johnson syndrome, may develop, presenting as a painful rash, peeling skin, or blisters.<\/li>\n\n\n\n<li><strong>Severe allergic reactions<\/strong>: Symptoms of a serious allergic response to diltiazem ER include trouble breathing, throat tightness, hives, and swelling of the face, lips, or tongue.<\/li>\n<\/ul>\n\n<\/div>\n\n\n\n<p class=\"has-muted-color has-text-color\" style=\"font-size:0.875rem\"><em>Call your doctor immediately if you experience any concerning or prolonged symptoms.<\/em><\/p>\n\n\t<\/div>\n<\/section>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-pharmacist-tips\">Pharmacist Tips<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-be-consistent\">Be Consistent<\/h3>\n\n\n\n<p>Standard guidelines recommend taking diltiazem ER at the same time each day to maintain steady blood levels.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-swallow-capsules-whole\">Swallow Capsules Whole<\/h3>\n\n\n\n<p>It is generally accepted that you should not chew, cut, or crush extended-release capsules or tablets, as this affects the coating that controls the medication&#8217;s slow release.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-be-cautious-with-dizziness\">Be Cautious With Dizziness<\/h3>\n\n\n\n<p>If you feel lightheaded when starting the medication or increasing the dose, providers recommend sitting down slowly and waiting for the dizziness to pass. If dizziness persists or becomes severe, contact your doctor or seek medical attention.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-address-fluid-retention\">Address Fluid Retention<\/h3>\n\n\n\n<p>Swelling in the ankles and feet is a known potential side effect of diltiazem ER. Standard guidelines suggest elevating your legs when sitting or wearing compression socks to help counteract fluid buildup.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-monitor-blood-pressure-at-home\">Monitor Blood Pressure At Home<\/h3>\n\n\n\n<p>Providers typically recommend keeping a log of your daily blood pressure readings to help your care team understand how well the medication is working.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-avoid-abrupt-discontinuation\">Avoid Abrupt Discontinuation<\/h3>\n\n\n\n<p>Pharmacists and doctors caution against discontinuing diltiazem ER abruptly. Sudden stoppage can affect your blood pressure.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-limit-alcohol-intake\">Limit Alcohol Intake<\/h3>\n\n\n\n<p>Drinking alcohol is generally not recommended while taking this medication, as it can change the way the medicine is absorbed and heighten the risk of dizziness and low blood pressure.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"h-protect-your-skin\">Protect Your Skin<\/h3>\n\n\n\n<p>Diltiazem ER can make your skin more sensitive to sunlight. Standard guidelines suggest wearing protective clothing and sunscreen when spending time outdoors.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"h-drug-interactions\">Drug Interactions<\/h2>\n\n\n\n<p>Certain medications and substances can interact with diltiazem ER, potentially altering how it works or increasing the risk of side effects.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Beta-blockers<\/strong>: Combining diltiazem with beta-blockers can increase the risk of heart-related complications, including excessive slowing of your heart rate.<\/li>\n\n\n\n<li><strong>Statin medications<\/strong>: Cholesterol-lowering drugs may interact with this medication and require your provider to adjust your medication dosages.<\/li>\n\n\n\n<li><strong>Digoxin<\/strong>: Taking this medication alongside diltiazem can increase the risk of digoxin toxicity and elevate the risk of experiencing a significant drop in heart rate.<\/li>\n\n\n\n<li><strong>Benzodiazepines<\/strong>: Anti-anxiety medications can interact with diltiazem and potentially worsen side effects.<\/li>\n\n\n\n<li><strong>Carbamazepine<\/strong>: This medication is known to interact with diltiazem, and using them together requires close medical monitoring.<\/li>\n\n\n\n<li><strong>Other blood pressure medications<\/strong>: Taking diltiazem ER with other blood pressure medications can cause a compounded effect, lowering your blood pressure too much.<\/li>\n\n\n\n<li><strong>Cimetidine<\/strong>: This medication may alter diltiazem blood levels and affect how the body processes it.<\/li>\n\n\n\n<li><strong>Cyclosporine<\/strong>: This drug may interact with diltiazem, requiring close medical monitoring to ensure safe use.<\/li>\n<\/ul>\n\n\n\n<p>Always give your doctor and pharmacist a complete list of all your medications, vitamins, and supplements to check for potential interactions.<\/p>\n\n\n\n<section class=\"telyrx-faq-section\" data-toc-title=\"FAQs\">\n\t<h2 class=\"telyrx-faq-heading\">FAQs<\/h2>\n\t\t<div class=\"telyrx-faq-items\">\n\t\t\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">How long does it typically take for an extended-release diltiazem capsule to lower my blood pressure?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>While diltiazem ER begins to work within a few hours after your first dose, it can take 2 to 4 weeks to see its full effect on your blood pressure. If your blood pressure remains outside the target range after this period, your provider may adjust your dosage.<\/p>\n\n\t<\/div>\n<\/details>\n\n\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">Will taking this medication cause swelling or fluid retention in my ankles and feet?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>Fluid retention, which can occur in the hands, lower legs, ankles, or feet, is a recognized side effect of diltiazem ER. Providers typically recommend elevating your legs while resting to help reduce swelling.<\/p>\n\n\t<\/div>\n<\/details>\n\n\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">Can I take diltiazem at the same time as my cholesterol pills?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>Diltiazem is known to interact with certain statin medications used for lowering cholesterol, such as atorvastatin, simvastatin, and lovastatin. Consult your doctor or pharmacist before taking these medications together.<\/p>\n\n\t<\/div>\n<\/details>\n\n\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">Can I take over-the-counter cold medicines that contain decongestants while on this?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>Check with your pharmacist or doctor before using any over-the-counter medications, including cold and flu products, when you are taking diltiazem ER. Some ingredients in over-the-counter medications can interfere with how diltiazem ER works or can cause unintended drug interactions.<\/p>\n\n\t<\/div>\n<\/details>\n\n\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">Why do I have to take the immediate-release tablet three to four times a day, but the capsule only once?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>Extended-release capsules are manufactured with a specialized coating that gradually releases the medication into your bloodstream over a longer period. This allows for a once-daily schedule, which some people find more convenient. Immediate-release tablets enter the system quickly, so multiple doses during the day are needed to sustain the medication&#8217;s effects.<\/p>\n\n\t<\/div>\n<\/details>\n\n\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">Will this medication cure my atrial fibrillation, or does it just manage symptoms?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>Research indicates that diltiazem ER does not cure atrial fibrillation. Instead, it may help manage the condition by slowing your heart rate and easing the heart&#8217;s workload.<\/p>\n\n\t<\/div>\n<\/details>\n\n\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">Can taking diltiazem cause me to feel constantly fatigued?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>Feeling unusually tired, weak, or fatigued is a common side effect of diltiazem ER, especially when you first start taking the medication or increase your dose. This often improves as your body adjusts to different blood pressure levels.<\/p>\n\n\t<\/div>\n<\/details>\n\n\n\n<details class=\"telyrx-faq-item\">\n\t<summary class=\"telyrx-faq-question\">\n\t\t<span class=\"telyrx-faq-question-text\">Are generic diltiazem ER capsules as effective as brand names like Cardizem CD or Tiazac?<\/span>\n\t\t<svg class=\"telyrx-faq-chevron\" width=\"20\" height=\"20\" viewBox=\"0 0 20 20\" fill=\"none\" aria-hidden=\"true\">\n\t\t\t<path d=\"M5 7.5L10 12.5L15 7.5\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\/>\n\t\t<\/svg>\n\t<\/summary>\n\t<div class=\"telyrx-faq-answer\">\n\t\t\n\n<p>Generic versions of diltiazem ER are available and provide the same benefits as their brand-name counterparts. However, because brands use different extended-release mechanisms, they are not always interchangeable. As a result, providers recommend using only the specific version that you have been prescribed.<\/p>\n\n\t<\/div>\n<\/details>\n\n\t<\/div>\n<\/section>\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"How long does it typically take for an extended-release diltiazem capsule to lower my blood pressure?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"While diltiazem ER begins to work within a few hours after your first dose, it can take 2 to 4 weeks to see its full effect on your blood pressure. If your blood pressure remains outside the target range after this period, your provider may adjust your dosage.\"}},{\"@type\":\"Question\",\"name\":\"Will taking this medication cause swelling or fluid retention in my ankles and feet?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Fluid retention, which can occur in the hands, lower legs, ankles, or feet, is a recognized side effect of diltiazem ER. Providers typically recommend elevating your legs while resting to help reduce swelling.\"}},{\"@type\":\"Question\",\"name\":\"Can I take diltiazem at the same time as my cholesterol pills?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Diltiazem is known to interact with certain statin medications used for lowering cholesterol, such as atorvastatin, simvastatin, and lovastatin. Consult your doctor or pharmacist before taking these medications together.\"}},{\"@type\":\"Question\",\"name\":\"Can I take over-the-counter cold medicines that contain decongestants while on this?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Check with your pharmacist or doctor before using any over-the-counter medications, including cold and flu products, when you are taking diltiazem ER. Some ingredients in over-the-counter medications can interfere with how diltiazem ER works or can cause unintended drug interactions.\"}},{\"@type\":\"Question\",\"name\":\"Why do I have to take the immediate-release tablet three to four times a day, but the capsule only once?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Extended-release capsules are manufactured with a specialized coating that gradually releases the medication into your bloodstream over a longer period. This allows for a once-daily schedule, which some people find more convenient. 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This often improves as your body adjusts to different blood pressure levels.\"}},{\"@type\":\"Question\",\"name\":\"Are generic diltiazem ER capsules as effective as brand names like Cardizem CD or Tiazac?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Generic versions of diltiazem ER are available and provide the same benefits as their brand-name counterparts. However, because brands use different extended-release mechanisms, they are not always interchangeable. As a result, providers recommend using only the specific version that you have been prescribed.\"}}]}<\/script>\n\n<div class=\"telyrx-comparable-medications wp-block-telyrx-comparable-medications\">\n\t<h2 class=\"telyrx-comparable-medications__title\">Comparable Medications<\/h2>\n\t\t\t<div class=\"telyrx-comparable-medications__intro\">\n\n<p><strong><strong><strong>Diltiazem, Amlodipine (Norvasc), Verapamil (Calan), Metoprolol (Toprol XL), Amiodarone?<\/strong><\/strong><\/strong><\/p>\n\n<\/div>\n\t\t\t\t<div class=\"telyrx-comparable-medications__item\">\n\t\t\t<div class=\"telyrx-comparable-medications__item-top\">\n\t\t\t\t<div class=\"telyrx-comparable-medications__item-info\">\n\t\t\t\t\t<h3 class=\"telyrx-comparable-medications__name\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"telyrx-comparable-medications__name-link\" href=\"https:\/\/telyrx.com\/medications\/amlodipine\">\n\t\t\t\t\t\t\t\tAmlodipine\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t<\/h3>\n\n\t\t\t\t\t\t\t\t\t\t\t<p class=\"telyrx-comparable-medications__price\">\n\t\t\t\t\t\t\tFrom $27.99\t\t\t\t\t\t<\/p>\n\t\t\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t\t\t<a class=\"telyrx-comparable-medications__cta\" href=\"https:\/\/telyrx.com\/medications\/amlodipine\">\n\t\t\t\t\t\tView Product\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t<p class=\"telyrx-comparable-medications__description\">\n\t\t\t\t\tThis medication is another widely utilized dihydropyridine calcium channel blocker that providers may prescribe for cardiovascular conditions.\t\t\t\t<\/p>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<hr class=\"telyrx-comparable-medications__divider\">\n\t\t\t\t\t<div class=\"telyrx-comparable-medications__item\">\n\t\t\t<div class=\"telyrx-comparable-medications__item-top\">\n\t\t\t\t<div class=\"telyrx-comparable-medications__item-info\">\n\t\t\t\t\t<h3 class=\"telyrx-comparable-medications__name\">\n\t\t\t\t\t\t\t\t\t\t\t\t\tVerapamil\t\t\t\t\t\t\t\t\t\t\t<\/h3>\n\n\t\t\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t<p class=\"telyrx-comparable-medications__description\">\n\t\t\t\t\tSimilar to diltiazem, this drug is a non-dihydropyridine calcium channel blocker used to manage blood pressure and support heart function.\t\t\t\t<\/p>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<hr class=\"telyrx-comparable-medications__divider\">\n\t\t\t\t\t<div class=\"telyrx-comparable-medications__item\">\n\t\t\t<div class=\"telyrx-comparable-medications__item-top\">\n\t\t\t\t<div class=\"telyrx-comparable-medications__item-info\">\n\t\t\t\t\t<h3 class=\"telyrx-comparable-medications__name\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"telyrx-comparable-medications__name-link\" href=\"https:\/\/telyrx.com\/medications\/metoprolol-succinate-er\">\n\t\t\t\t\t\t\t\tMetoprolol Succinate ER\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t<\/h3>\n\n\t\t\t\t\t\t\t\t\t\t\t<p class=\"telyrx-comparable-medications__price\">\n\t\t\t\t\t\t\tFrom $24.99\t\t\t\t\t\t<\/p>\n\t\t\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t\t\t<a class=\"telyrx-comparable-medications__cta\" href=\"https:\/\/telyrx.com\/medications\/metoprolol-succinate-er\">\n\t\t\t\t\t\tView Product\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t<p class=\"telyrx-comparable-medications__description\">\n\t\t\t\t\tThis medication is a beta-blocker, and beta-blockers lower blood pressure through a different mechanism than calcium channel blockers like diltiazem ER.\t\t\t\t<\/p>\n\t\t\t\t\t<\/div>\n\n\t\t\t\t\t<hr class=\"telyrx-comparable-medications__divider\">\n\t\t\t\t\t<div class=\"telyrx-comparable-medications__item\">\n\t\t\t<div class=\"telyrx-comparable-medications__item-top\">\n\t\t\t\t<div class=\"telyrx-comparable-medications__item-info\">\n\t\t\t\t\t<h3 class=\"telyrx-comparable-medications__name\">\n\t\t\t\t\t\t\t\t\t\t\t\t\tAmiodarone\t\t\t\t\t\t\t\t\t\t\t<\/h3>\n\n\t\t\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t<p class=\"telyrx-comparable-medications__description\">\n\t\t\t\t\tThis is used for heart rhythm problems, and it should be used under careful medical supervision because of its potential for interactions with other drugs.\t\t\t\t<\/p>\n\t\t\t\t\t<\/div>\n\n\t\t\t<\/div>\n\n\n<div class=\"telyrx-product-list telyrx-product-list--single wp-block-telyrx-product-list\">\n\t\t\t\t\t<a class=\"telyrx-product-list__card telyrx-product-list__card--single\" href=\"https:\/\/telyrx.com\/medications\/diltiazem-er-cd-capsules\">\n\t\t\t\t\t\t\t<img\n\t\t\t\t\tclass=\"telyrx-product-list__image\"\n\t\t\t\t\tsrc=\"https:\/\/telyrx.com\/media\/catalog\/product\/d\/i\/diltiazem_er_cd_capsules_120_mg_001_20260316_sq-bg_ai_gen_1_10.png\"\n\t\t\t\t\talt=\"Diltiazem ER (CD) Capsules\"\n\t\t\t\t\twidth=\"213\"\n\t\t\t\t\theight=\"213\"\n\t\t\t\t\tloading=\"lazy\"\n\t\t\t\t>\n\t\t\t\t\t\t<div class=\"telyrx-product-list__content\">\n\t\t\t\t<p class=\"telyrx-product-list__name\">Diltiazem ER (CD) Capsules<\/p>\n\t\t\t\t<span class=\"telyrx-product-list__cta telyrx-product-list__cta--yellow\">\n\t\t\t\t\tView Product\t\t\t\t<\/span>\n\t\t\t<\/div>\n\t\t<\/a>\n\t<\/div>\n\n\n<div class=\"telyrx-product-list-section alignfull wp-block-telyrx-product-list\">\n\t<h2 class=\"telyrx-product-list-section__heading\" data-toc-hidden=\"true\">We Have Diltiazem ER in Stock. Get Yours Today!<\/h2>\n\t<div class=\"telyrx-product-list telyrx-product-list--footer-multi\">\n\t\t<div class=\"telyrx-product-list__grid\">\n\t\t\t\t\t\t\t<a class=\"telyrx-product-list__card\" href=\"https:\/\/telyrx.com\/medications\/diltiazem-er-cd-capsules\">\n\t\t\t\t\t\t\t\t\t\t\t<img\n\t\t\t\t\t\t\tclass=\"telyrx-product-list__image\"\n\t\t\t\t\t\t\tsrc=\"https:\/\/telyrx.com\/media\/catalog\/product\/d\/i\/diltiazem_er_cd_capsules_120_mg_001_20260316_sq-bg_ai_gen_1_10.png\"\n\t\t\t\t\t\t\talt=\"Diltiazem ER (CD) Capsules\"\n\t\t\t\t\t\t\twidth=\"213\"\n\t\t\t\t\t\t\theight=\"213\"\n\t\t\t\t\t\t\tloading=\"lazy\"\n\t\t\t\t\t\t>\n\t\t\t\t\t\t\t\t\t\t<div class=\"telyrx-product-list__content\">\n\t\t\t\t\t\t<p class=\"telyrx-product-list__name\">Diltiazem ER (CD) Capsules<\/p>\n\t\t\t\t\t\t<span class=\"telyrx-product-list__cta telyrx-product-list__cta--yellow\">\n\t\t\t\t\t\t\tOrder Now\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/a>\n\t\t\t\t\t<\/div>\n\t<\/div>\n\t\t\t<div class=\"telyrx-product-list-section__extra\">\n\t\t\t<p class=\"has-muted-color has-text-color has-urbanist-font-family\" style=\"font-size:0.875rem;font-style:italic;font-weight:400;line-height:1.571\"><strong>Important:<\/strong> Information on this page is for educational purposes only. Prescribing decisions are made by independent, licensed providers. TelyRx operates technology-enabled pharmacies and a telehealth platform that connects patients with licensed providers. Prescriptions, when provider-approved and issued, are filled and shipped by TelyRx-affiliated pharmacies. We do not employ physicians or make prescribing decisions. Learn more about our editorial standards <a href=\"\/blog\/editorial-standards\/\">here<\/a>.<\/p>\t\t<\/div>\n\t<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Diltiazem extended-release (ER) is prescribed primarily to manage high blood pressure (hypertension), chest pain (angina), and certain heart rhythm disorders (arrhythmias). <\/p>\n<p>As a long-acting capsule or tablet, it is designed for once- or twice-daily dosing. Guidelines indicate that diltiazem ER can help reduce cardiac strain and improve cardiovascular function.<\/p>\n","protected":false},"author":2,"featured_media":9019,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"single-medication","format":"standard","meta":{"content-type":"","telyrx_subtitle":"Uses, Side Effects, Dosage & FAQs (2026 Guide)","telyrx_last_updated":"2026-06-03T15:43","telyrx_reviewer_name":"Ashley Robinson","telyrx_reviewer_credentials":"PharmD","telyrx_reviewer_job_title":"Pharmacy Manager","telyrx_reviewer_affiliation":"TelyRx","telyrx_reviewer_url":"","telyrx_show_reviewer_job_title":"0","telyrx_show_reviewer_affiliation":"0","telyrx_show_toc":"1","telyrx_reviewer_bio":"","telyrx_reviewer_avatar":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","_telyrx_clean_url":"\/medications\/diltiazem-er-cd-capsules\/what-is\/"},"categories":[86],"tags":[],"class_list":["post-9018","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-medications"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v27.6 (Yoast SEO v27.6) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>What Is Diltiazem ER? Uses, Side Effects, Dosage, and FAQs<\/title>\n<meta name=\"description\" content=\"Learn what diltiazem ER is, how it works, common side effects, and how to get it prescribed online through TelyRx.com\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/telyrx.com\/blog\/medications\/what-is-diltiazem-er-cd-capsules\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"What Is Diltiazem ER?\" \/>\n<meta property=\"og:description\" content=\"Learn what diltiazem ER is, how it works, common side effects, and how to get it prescribed online through TelyRx.com\" \/>\n<meta property=\"og:url\" content=\"https:\/\/telyrx.com\/blog\/medications\/what-is-diltiazem-er-cd-capsules\/\" \/>\n<meta property=\"og:site_name\" content=\"TelyRx Blog\" \/>\n<meta property=\"article:published_time\" content=\"2026-06-03T15:43:26+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-06-03T15:43:43+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/telyrx.com\/blog\/wp-content\/uploads\/2026\/06\/diltiazem_er_cd_capsules_120_mg_001_20260316_sq-bg_ai_gen_1_10.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"900\" \/>\n\t<meta property=\"og:image:height\" content=\"900\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Mariah Powers\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Mariah Powers\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/medications\\\/what-is-diltiazem-er-cd-capsules\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/medications\\\/what-is-diltiazem-er-cd-capsules\\\/\"},\"author\":{\"name\":\"Mariah Powers\",\"@id\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/#\\\/schema\\\/person\\\/f1042a29c24ab7dd3c5f0fff9a06746b\"},\"headline\":\"What Is Diltiazem ER?\",\"datePublished\":\"2026-06-03T15:43:26+00:00\",\"dateModified\":\"2026-06-03T15:43:26+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/medications\\\/what-is-diltiazem-er-cd-capsules\\\/\"},\"wordCount\":1367,\"publisher\":{\"@id\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/medications\\\/what-is-diltiazem-er-cd-capsules\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/06\\\/diltiazem_er_cd_capsules_120_mg_001_20260316_sq-bg_ai_gen_1_10.jpg\",\"articleSection\":[\"Medications\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/medications\\\/what-is-diltiazem-er-cd-capsules\\\/\",\"url\":\"https:\\\/\\\/telyrx.com\\\/blog\\\/medications\\\/what-is-diltiazem-er-cd-capsules\\\/\",\"name\":\"What Is Diltiazem ER? 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