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:
When these two medicines are taken together, cimetidine may prevent your body from processing your calcium channel blocker properly.
What might happen:
The effects of your calcium blocker may increase.
What you should do about this interaction:
If you experience weakness, fatigue, dizziness, or a fast heartbeat, contact your doctor. It may be necessary to adjust the dose of your calcium channel blocker or change your cimetidine to a different medicine.Your healthcare professionals (e.g. doctor or pharmacist) 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.Smith SR, Kendall MJ, Lobo J, Beerahee A, Jack DB, Wilkins MR. Ranitidine and cimetidine; drug interactions with single dose and steady-state nifedipine administration. Br J Clin Pharmacol 1987 Mar;23(3):311-5.
2.Schwartz JB, Upton RA, Lin ET, Williams RL, Benet LZ. Effect of cimetidine or ranitidine administration on nifedipine pharmacokinetics and pharmacodynamics. Clin Pharmacol Ther 1988 Jun;43(6):673-80.
3.Khan A, Langley SJ, Mullins FG, Dixon JS, Toon S. The pharmacokinetics and pharmacodynamics of nifedipine at steady state during concomitant administration of cimetidine or high dose ranitidine. Br J Clin Pharmacol 1991 Oct;32(4):519-22.
4.Guengerich FP, Brian WR, Iwasaki M, Sari MA, Baarnhielm C, Berntsson P. Oxidation of dihydropyridine calcium channel blockers and analogues by human liver cytochrome P-450 IIIA4. J Med Chem 1991 Jun;34(6):1838-44.
5.Plendil (felodipine) US prescribing information. AstraZeneca Pharmaceuticals LP November, 2003.
6.Humphries TJ. Famotidine: a notable lack of drug interactions. Scand J Gastroenterol Suppl 1987;134:55-60.
7.Secor JW, Speeg KV Jr, Meredith CG, Johnson RF, Snowdy P, Schenker S. Lack of effect of nizatidine on hepatic drug metabolism in man. Br J Clin Pharmacol 1985 Dec;20(6):710-3.
8.Klotz U. Lack of effect of nizatidine on drug metabolism. Scand J Gastroenterol Suppl 1987;136:18-23.
9.Lin JH, Los LE, Ulm EH, Duggan DE. Kinetic studies on the competition between famotidine and cimetidine in rats. Evidence of multiple renal secretory systems for organic cations. Drug Metab Dispos 1988 Jan-Feb; 16(1):52-6.
10.Wang RW, Miwa GT, Argenbright LS, Lu AY. In vitro studies on the interaction of famotidine with liver microsomal cytochrome P-450. Biochem Pharmacol 1988 Aug 1;37(15):3049-53.
11.Kirch W, Hoensch H, Janisch HD. Interactions and non-interactions with ranitidine. Clin Pharmacokinet 1984 Nov-Dec;9(6):493-510.
12.Renwick AG, Le Vie J, Challenor VF, Waller DG, Gruchy B, George CF. Factors affecting the pharmacokinetics of nifedipine. Eur J Clin Pharmacol 1987;32(4):351-5.
13.Winship LC, McKenney JM, Wright JT Jr, Wood JH, Goodman RP. The effect of ranitidine and cimetidine on single-dose diltiazem pharmacokinetics. Pharmacotherapy 1985 Jan-Feb;5(1):16-9.
14.Kirch W, Ramsch K, Janisch HD, Ohnhaus EE. The influence of two histamine H2-receptor antagonists, cimetidine and ranitidine, on the plasma levels and clinical effect of nifedipine and metoprolol. Arch Toxicol Suppl 1984;7:256-9.
15.Procardia (nifedipine) US prescribing information. Pfizer Inc. July, 2013.
16.Cardizem LA (diltiazem hcl extended release tablets) US prescribing information. Abbott Pharmaceuticals, Inc. November, 2010.
17.Cardene (nicardipine) US prescribing information. EKR Therapeutics, Inc. July, 2014.
18.Dynacirc (isradipine) US prescribing information. Reliant Pharmaceuticals December, 2006.