Comprehensive medication guide to Isradipine including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$40 copay per 30-day fill on most commercial insurance plans (Tier 2-3); covered by most Medicare Part D plans with the $2,000 annual out-of-pocket cap as of 2025; prior authorization is uncommon for this generic.
Estimated Cash Pricing
$246–$910 retail for generic isradipine without insurance; as low as $188 with a GoodRx coupon or around $93 with SingleCare for a 30-day supply of 5 mg capsules.
Medfinder Findability Score
52/100
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Isradipine is a prescription calcium channel blocker (CCB) in the dihydropyridine subclass, approved by the FDA for the treatment of hypertension (high blood pressure). It was originally marketed under the brand names DynaCirc and DynaCirc CR, both of which have been permanently discontinued. As of 2026, only generic isradipine capsules — manufactured by Teva Pharmaceuticals — are available in the United States.
Isradipine is prescribed for adults with hypertension, either alone or in combination with thiazide-type diuretics. It has also been used off-label for the management of acute severe hypertension in hospitalized pediatric patients, where it has demonstrated effective and predictable blood pressure reduction in multiple clinical studies.
Isradipine is not a controlled substance and can be prescribed by any licensed healthcare provider with prescribing authority, including primary care physicians, internists, cardiologists, nephrologists, nurse practitioners, and physician assistants.
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Isradipine works by blocking L-type calcium channels in the smooth muscle cells lining arterial walls. Calcium ions are required for smooth muscle contraction — when isradipine blocks these channels, the muscle cells cannot contract as forcefully, causing the arteries to relax and widen (vasodilation). This reduces peripheral vascular resistance, meaning the heart pumps against less resistance, and blood pressure decreases.
As a second-generation dihydropyridine CCB, isradipine has high vascular selectivity — it primarily acts on arterial smooth muscle with minimal direct effect on cardiac conduction. This distinguishes it from non-dihydropyridine CCBs (like diltiazem and verapamil), which also slow heart rate. Isradipine may cause a mild reflex increase in heart rate due to the vasodilatory response, which is typically self-limiting.
Isradipine begins to lower blood pressure within 2-3 hours of a dose. Full antihypertensive effect with regular twice-daily dosing develops over 2-4 weeks. It also exhibits a mild diuretic effect, which may complement its blood pressure-lowering action, though the exact mechanism of this is not fully understood.
2.5 mg — capsule
Starting dose; taken twice daily (BID); initial antihypertensive dose for most adults
5 mg — capsule
Maintenance dose; taken twice daily; most patients are adequately controlled at 10 mg/day total (5 mg BID)
Isradipine can be challenging to find at retail pharmacies in 2026. Although an official ASHP-tracked shortage that began in February 2023 was resolved by December 2023, the medication remains inconsistently stocked because only one manufacturer — Teva Pharmaceuticals — currently supplies the U.S. market. The brand-name versions (DynaCirc and DynaCirc CR) have been permanently discontinued, leaving no branded fallback.
Because isradipine is a lower-volume drug compared to widely-prescribed alternatives like amlodipine, many pharmacies do not maintain regular stock. Patients may need to call ahead or ask the pharmacist to place a special order, which typically arrives within 1-2 business days through standard wholesale channels.
To avoid calling pharmacies one at a time, patients can use medfinder — a service that contacts pharmacies on your behalf to find out which ones have isradipine in stock and can fill your prescription. Results are texted to you directly.
Isradipine is not a controlled substance and has no DEA scheduling restrictions. Any licensed healthcare provider with prescribing authority in their state can prescribe isradipine as part of hypertension management. No special certification, REMS program, or DEA registration requirements apply to isradipine prescribing.
Isradipine is commonly prescribed by:
Since isradipine is not a controlled substance, it can also be prescribed through telehealth platforms (such as Teladoc, MDLive, and Amazon Clinic) without any additional DEA requirements, making it accessible to patients who prefer or need remote care.
No. Isradipine is not classified as a controlled substance by the DEA and is not assigned to any DEA schedule (Schedule I through V). It is a standard prescription-only medication, meaning a valid prescription from a licensed provider is required to fill it, but there are no special prescribing restrictions, quantity limits, or reporting requirements associated with controlled substance status.
Because isradipine is not a controlled substance, it can be prescribed electronically, called in by phone, or issued via telehealth without any DEA-related restrictions. Prescriptions can be written for 90-day supplies where appropriate. There are no mandatory prescription drug monitoring program (PDMP) checks required for isradipine prescriptions.
These side effects are common and often improve as your body adjusts to the medication:
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Amlodipine (Norvasc)
Once-daily dihydropyridine CCB; widely available and inexpensive generic; also indicated for CAD and angina; may cause more peripheral edema than isradipine in some patients
Nifedipine ER (Procardia XL)
Once-daily extended-release dihydropyridine CCB; one of the least expensive antihypertensives available (under $10/month generic); use ER formulation only
Felodipine (Plendil)
Second-generation dihydropyridine CCB pharmacologically similar to isradipine; once-daily ER formulation; direct comparison studies show similar blood pressure reduction
Diltiazem (Cardizem)
Non-dihydropyridine CCB; also slows heart rate; preferred when both hypertension and rate control (e.g., atrial fibrillation) are needed; widely available generic
Prefer Isradipine? We can find it.
Rifampin
majorStrong CYP3A4 inducer; reduces isradipine plasma levels to below detectable limits, rendering it ineffective. Avoid combination; use alternative antihypertensive.
Strong CYP3A4 inhibitors (ketoconazole, itraconazole, clarithromycin, idelalisib)
moderateSlow isradipine metabolism, significantly increasing blood levels and risk of hypotension, dizziness, and flushing. Dose reduction of isradipine may be needed.
QTc-prolonging drugs (adagrasib, ivosidenib, mefloquine, ondansetron)
majorAdditive QTc prolongation risk; may increase risk of Torsade de pointes and other serious arrhythmias. Avoid combination where possible; if unavoidable, ECG monitoring required.
Beta-blockers (atenolol, carvedilol, propranolol)
moderateAdditive blood pressure lowering; may worsen heart failure when combined. Monitor blood pressure and cardiac function closely.
Grapefruit juice
moderateInhibits intestinal CYP3A4, increasing isradipine absorption and blood levels. Limit or avoid grapefruit and grapefruit juice.
Cimetidine (Tagamet)
minorOTC heartburn medication that increases isradipine peak plasma levels; inform prescriber if taking cimetidine regularly.
Tizanidine
moderateSynergistic antihypertensive effect; avoid combination due to risk of excessive blood pressure lowering.
St. John's Wort
moderateHerbal CYP3A4 inducer; reduces isradipine efficacy. Avoid concurrent use.
Isradipine is a proven and effective antihypertensive medication that has been used clinically for over three decades. Its mechanism — selective L-type calcium channel blockade in arterial smooth muscle — provides predictable and effective blood pressure reduction. It holds a particular clinical niche in pediatric hypertension management and for adult patients who have had tolerability issues with other calcium channel blockers.
The main challenges with isradipine in 2026 are availability and cost. With only Teva as a manufacturer and no branded version, pharmacy stock can be inconsistent. Patients should plan refills early, call ahead to confirm availability, and use discount tools like GoodRx or SingleCare to manage costs. Proactive communication with your prescriber about access challenges is important — a backup plan with a readily available alternative can prevent dangerous lapses in blood pressure control.
If you are struggling to find isradipine at your pharmacy, medfinder can contact pharmacies near you on your behalf to find where it is currently in stock — saving you time and helping you stay on your medication.
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Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
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