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Trade namesDynaCirc, Prescal
  • 3-methyl 5-propan-2-yl 4-(2,1,3-benzoxadiazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate
Clinical data
Drug classCalcium channel blocker (dihydropyridine)
Main usesHigh blood pressure[1]
Side effectsHeadache, swelling, palpitations, lightheadedness[1]
  • C
Routes of
By mouth
External links
Legal status
Protein binding95%
Metabolism100% liver
Elimination half-life8 hours
Excretion70% kidney, 30% fecal
Chemical and physical data
Molar mass371.393 g·mol−1
3D model (JSmol)
  • O=C(OC)\C3=C(\N\C(=C(\C(=O)OC(C)C)C3c1cccc2nonc12)C)C
  • InChI=1S/C19H21N3O5/c1-9(2)26-19(24)15-11(4)20-10(3)14(18(23)25-5)16(15)12-7-6-8-13-17(12)22-27-21-13/h6-9,16,20H,1-5H3 checkY

Isradipine, sold under the brand name DynaCirc among others, is a medication used to treat high blood pressure.[1] For this use it is one of a number of first line agents.[1] It is taken by mouth.[1] Maximal effect may take up to four weeks.[1]

Common side effects include headache, swelling, palpitations, and lightheadedness.[1] Other side effects may include worsening heart failure, chest pain, and low blood pressure.[1] Safety in pregnancy is unclear.[2] It is a calcium channel blocker of the dihydropyridine class.[1]

Isradipine was patented in 1978 and approved for medical use in 1989.[3] IT is available as a generic medication.[4] In the United States, at a dose of 5 mg twice per day, it costs about 27 USD per month.[4]

Medical uses


It is often started at a dose of 1.25 to 2.5 mg twice per day.[1] The maximum dose is 20 mg per day.[1]

Isradipine is given as either a 2.5 mg or 5 mg capsule.[5]

Side effects

Common side effects include: [6]

  • Dizziness
  • Warmth, redness, or tingly feeling under your skin
  • Headache
  • Weakness, tired feeling
  • Nausea, vomiting, diarrhea, upset stomach
  • Skin rash or itching

Serious side effects include: [6]

  • Lightheadedness or fainting
  • Shortness of breath, especially from minimal physical activity
  • Swelling in the hands and feet
  • Rapid and/or heavy heartbeat
  • Chest pain


It is advised that those using Isradipine not take Anzemet (Dolasetron), as both agents can cause a dose-dependent PR interval and QRS complex prolongation.[7]

Itraconazole exhibits a negative inotropic effect on the heart and thus could spur an additive effect when used concomitantly with Isradipine. Onmel/Sporanox also inhibits an important cytochrome liver enzyme (CYP 450 3A4) which is needed to metabolize Isradipine and other Calcium Channel Blockers. This will increase plasma levels of Isradipine and could cause an unintentional overdose of the medication. Caution is advised when administering both agents together.[8]

Tizanidine demonstrates anti-hypertensive effects and should be avoided in patients taking Isradipine due to the possibility of synergism between both medications.[9]

The anti-biotic Rifampin lowered plasma concentrations of Isradipine to below detectable limits.[5]

Cimetidine increased Isradipine mean peak plasma levels. A downward dose adjustment may be necessary with this particular instance of polypharmacy.[5]

Severe hypotension was reported with Fentanyl anesthesia when it was combined with other Calcium Channel Blockers. Even though Isradipine, another Calcium Channel Blocker, has not been used in conjunction with Fentanyl anesthesia in any studies, caution is advised.[5]

Note: There was no significant interaction between Isradipine and Warfarin (Coumadin), Isradipine and Microzide Hydrochlorothiazide, Isradipine and Lanoxin (Digoxin), and Isradipine and Nitrostat (Nitroglycerin).


Symptoms of an Isradipine overdose include:[5]


Isradipine contains a stereocenter and consists of two enantiomers, more precisely atropisomers. This is a racemate, i.e. a 1: 1 mixture of ( R ) - and the ( S ) - Form:[10]

Enantiomers of Isradipine

CAS-Nummer: 84260-63-9

CAS-Nummer: 84260-64-0


  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 "Isradipine Monograph for Professionals". Archived from the original on 31 August 2021. Retrieved 1 December 2021.
  2. "Isradipine Use During Pregnancy". Archived from the original on 24 October 2020. Retrieved 1 December 2021.
  3. Fischer, Jnos; Ganellin, C. Robin (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 465. ISBN 9783527607495. Archived from the original on 2021-08-27. Retrieved 2021-10-09.
  4. 4.0 4.1 "Isradipine Prices, Coupons & Savings Tips". GoodRx. Archived from the original on 20 September 2016. Retrieved 1 December 2021.
  5. 5.0 5.1 5.2 5.3 5.4 "Isradipine: Brands, Medical Use, Clinical Data". Archived from the original on 2019-09-13. Retrieved 2021-10-09.
  6. 6.0 6.1 "Isradipine Side Effects". Archived from the original on 2021-09-01. Retrieved 2021-10-09.
  7. "Isradipine and Anzemet Drug Interactions". Archived from the original on 2021-08-30. Retrieved 2021-10-09.
  8. "Isradipine and Onmel Drug Interactions". Archived from the original on 2021-08-30. Retrieved 2021-10-09.
  9. "Isradipine and Zanaflex Drug Interactions". Archived from the original on 2021-08-30. Retrieved 2021-10-09.
  10. Rote Liste Service GmbH (Hrsg.): Rote Liste 2017 – Arzneimittelverzeichnis für Deutschland (einschließlich EU-Zulassungen und bestimmter Medizinprodukte). Rote Liste Service GmbH, Frankfurt/Main, 2017, Aufl. 57, ISBN 978-3-946057-10-9, S. 193.

Further reading

External links