Selected Calcium Channel Blockers/Selected Strong CYP3A4 Inhibitors Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Your medicine may decrease the ability of your liver to remove your heart medicine from your body.

What might happen:

The levels of your heart medicine in your body may cause your blood pressure to decrease too much. Symptoms of low blood pressure include: irregular heartbeat, lightheadedness, nausea, drowsiness, confusion, and slurred speech. You may also notice swelling in your legs and/or feet.

What you should do about this interaction:

Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want to decrease the dose of your heart medicine. Let your doctor know right away if you develop any signs of low blood pressure, a decreased heart rate, or swelling of the legs.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Cardizem LA (diltiazem hcl extended release tablets) US prescribing information. Abbott Pharmaceuticals, Inc. November, 2016.
  • 2.Plendil (felodipine) US prescribing information. AstraZeneca Pharmaceuticals LP November, 2003.
  • 3.Cardene (nicardipine) US prescribing information. EKR Therapeutics, Inc. August, 2016.
  • 4.Procardia (nifedipine) US prescribing information. Pfizer Inc. January 9, 2015.
  • 5.Calan (verapamil hydrochloride) US prescribing information. Pfizer, Inc. August, 2016.
  • 6.Jalava KM, Olkkola KT, Neuvonen PJ. Itraconazole greatly increases plasma concentrations and effects of felodipine. Clin Pharmacol Ther 1997 Apr; 61(4):410-5.
  • 7.Noxafil (posaconazole) US prescribing information. Merck & Co. Inc January, 2022.
  • 8.Niu W, Li S, Jin S, Lin X, Zhang M, Cai W, Jiao Z, Xiang X. Investigating the interaction between nifedipine- and ritonavir-containing antiviral regimens: A physiologically based pharmacokinetic/pharmacodynamic analysis. Br J Clin Pharmacol 2021 Jul;87(7):2790-2806.
  • 9.Neuvonen PJ, Suhonen R. Itraconazole interacts with felodipine. J Am Acad Dermatol 1995 Jul;33(1):134-5.
  • 10.Kremens B, Brendel E, Bald M, Czyborra P, Michel MC. Loss of blood pressure control on withdrawal of fluconazole during nifedipine therapy. Br J Clin Pharmacol 1999 Jun;47(6):707-8.
  • 11.Tailor SA, Gupta AK, Walker SE, Shear NH. Peripheral edema due to nifedipine-itraconazole interaction: a case report. Arch Dermatol 1996 Mar;132(3):350-2.
  • 12.Mishima E, Maruyama K, Nakazawa T, Abe T, Ito S. Acute Kidney Injury from Excessive Potentiation of Calcium-channel Blocker via Synergistic CYP3A4 Inhibition by Clarithromycin Plus Voriconazole. Intern Med 2017; 56(13):1687-1690.
  • 13.Shah SP, Self TH, Bradsher RW 3rd, Owens RE. Clarithromycin-nifedipine-induced acute kidney injury. Nurse Pract 2017 Sep 21;42(9):49-51.
  • 14.Cook RMD, Garcia-Gayoso AS, Twilla JD. Concomitant Use of Nifedipine and Clarithromycin Leading to Pulseless, Bradycardic Arrest. Am J Ther 2019 Jul/Aug;26(4):e543-e546.
  • 15.Baeza MT, Merino E, Boix V, Climent E. Nifedipine-lopinavir/ritonavir severe interaction: a case report. AIDS 2007 Jan 2;21(1):119-20.
  • 16.Zhao X, Zhang C, Zhu L, Wu B, Han Y, Heung M, Zuo L. Severe secondary hyperkalemia and arrhythmia from drug interactions between calcium-channel blocker and voriconazole: a case presentation. BMC Nephrol 2021 May 10;22(1):172.
  • 17.US Food and Drug Administration (FDA). Drug Development and Drug Interactions: Table of Substrates, Inhibitors and Inducers. Available at: -drug-interactions-table-substrates-inhibitors-and-inducers. Updated 11/14/2017.
  • 18.This information is based on an extract from the Certara Drug Interaction Database (DIDB) Platform, Copyright Certara 1999-2023..

Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, except as may be authorized by the applicable terms of use.

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.