What is Isradipine used for?

Isradipine is used to manage high blood pressure (hypertension).

How long does it take for Isradipine to work?

You may feel the blood pressure lowering effect within 2 to 3 hours, but it can take 2 to 4 weeks to see the full benefit.

Can I take Isradipine with other blood pressure medicines?

Yes, it can be used alone or along with a thiazide-type diuretic.

What are the most common side effects of Isradipine?

Common side effects include dizziness, swelling, heart palpitations, flushing, and headaches.

Is it safe to take Isradipine if I am pregnant?

Animal studies showed no direct harm to embryos, but you should only use it during pregnancy if directed by a doctor.

Can I breastfeed while taking Isradipine?

It is unknown if the drug enters breast milk, so you should talk to your doctor about the risks versus the benefits.

What should I do if I take too much Isradipine?

An overdose can cause lethargy and a fast heart rate; seek emergency medical attention immediately.

Does food affect how Isradipine works?

Eating food with Isradipine may delay how quickly the drug reaches its peak level, but it doesn't change the total amount absorbed.

Isradipine | CAS 75695-93-1 | HMJIYCCIJYRONP

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Calcium channel blocker

Isradipine is a calcium channel blocker used to treat high blood pressure (hypertension). It works by relaxing blood vessels so blood can flow more easily. It is taken by mouth in capsule form and may be used by itself or with a diuretic drug.

How it worksIsradipine blocks calcium from entering the muscle cells in your heart and blood vessels. This helps the blood vessels relax and widen, which lowers blood pressure.

Brand names:DYNACIRC CR, DYNACIRC

Used for

Hypertension (high blood pressure)

Conditions

Hypertension

Class

Calcium Channel BlockerAntagonistCalcium channel blockerCardiovascular

How to take

FormsOral capsule

RoutesOral

The starting dose is usually 2.5 mg taken twice a day. A doctor may adjust this dose up to a maximum of 20 mg per day, though most people do not need more than 10 mg per day.

The drug's effect usually starts within 2 to 3 hours, but it may take 2 to 4 weeks to reach its full effect. The dose should be customized by a healthcare provider based on your specific needs.

Key warnings

·Use with caution in elderly patients, those with liver problems, or those with mild kidney issues, as the drug may stay in the body longer.

Do not use if

·Do not use if you have a known allergy to any of the ingredients in the capsule.

Side effects

Common

DizzinessSwelling (edema)Heart palpitationsFlushingFast heart rate (tachycardia)HeadacheStomach upset

Serious

·Significant changes in heart rhythm
·Severe low blood pressure

Interactions

·Nitroglycerin (can be taken together safely)
·Hydrochlorothiazide (can be used together)
·Propranolol (may change how the body processes the drug)
·Cimetidine (interaction noted in studies)
·Other blood pressure medications like Adalat, Calan, Multaq, Cardene, Dilacor XR, Conjupri, Tiamate, Amvaz, Plendil, and Nimotop

FoodTaking Isradipine with food can delay the time it takes to reach peak levels in your body by about an hour, but it does not change the total amount of medicine absorbed.

Special populations

PregnancyIn animal studies, high doses caused some issues with pregnancy, but no direct harm to embryos was seen at doses that weren't harmful to the mother. Use during pregnancy should be discussed with a doctor.

BreastfeedingIt is not known if Isradipine passes into breast milk. Because of the potential for harm to a nursing baby, a doctor should help decide if it is safer to stop breastfeeding or stop taking the medication.

PediatricThe safety and effectiveness of Isradipine in children have not been established.

GeriatricElderly patients (over 65) may have higher levels of the drug in their system, so doses may need careful management.

Talk to your doctor

Monitor

·Blood pressure readings
·Swelling in the legs or ankles
·Heart rate and palpitations

Questions to ask

·How will Isradipine interact with my current blood pressure medications?
·Should I adjust my dose if I have liver or kidney issues?
·Is it safe to take Isradipine if I am planning to become pregnant?

Pharmacokinetics

OnsetDetectable in plasma within 20 minutes.

Half-lifeBiphasic elimination with an early half-life of 1.5 hours.

Bioavailability15% to 24% due to extensive first-pass metabolism.

Protein binding95% bound to plasma proteins.

MetabolismExtensive first-pass metabolism.

Practical

OverdoseOverdosing can cause extreme tiredness, a fast heart rate, or a dangerous drop in blood pressure. If an overdose is suspected, seek medical help immediately.

Ingredients

Allergens

lactose

Inactive

colloidal silicon dioxidered iron oxideyellow iron oxidegelatinanhydrous lactosemagnesium stearatesodium lauryl sulfatestarch (corn)titanium dioxideblack iron oxideshellacpotassium hydroxidepropylene glycol

Educational summary derived from FDA labeling, AI-assisted. Not medical advice — consult a healthcare professional. Updated 2026-04-25.