Metoprolol; Propranolol/Cimetidine
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:
When these two medicines are taken together, your body may not process your heart medicine properly.
What might happen:
An increase in the beneficial and toxic effects of your heart medicine may occur.
What you should do about this interaction:
If you experience slow heart rate, weakness, fatigue, or dizziness, contact your doctor. Your doctor may adjust the dose of your heart medicine or change your cimetidine to another medicine.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this drug interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
References:
1.Heagerty AM, Donovan MA, Castleden CM, Pohl JF, Patel L, Hedges A. Influence of cimetidine on pharmacokinetics of propranolol. Br Med J (Clin Res Ed) 1981 Jun 13;282(6280):1917-9.
2.Houtzagers JJ, Streurman O, Regardh CG. The effect of pretreatment with cimetidine on the bioavailability and disposition of atenolol and metoprolol. Br J Clin Pharmacol 1982 Jul;14(1):67-72.
3.Heagerty AM, Castleden CM, Patel L. Failure of ranitidine to interact with propranolol. Br Med J (Clin Res Ed) 1982 May 1;284(6325):1304.
4.Spahn H, Mutschler E, Kirch W, Ohnhaus EE, Janisch HD. Influence of ranitidine on plasma metoprolol and atenolol concentrations. Br Med J (Clin Res Ed) 1983 May 14;286(6377):1546-7.
5.Mutschler E, Spahn H, Kirch W. The interaction between H2-receptor antagonists and beta-adrenoceptor blockers. Br J Clin Pharmacol 1984;17 Suppl 1:51S-57S.
6.Kelly JG, Salem SA, Kinney CD, Shanks RG, McDevitt DG. Effects of ranitidine on the disposition of metoprolol. Br J Clin Pharmacol 1985 Feb; 19(2):219-24.
7.Toon S, Davidson EM, Garstang FM, Batra H, Bowes RJ, Rowland M. The racemic metoprolol H2-antagonist interaction. Clin Pharmacol Ther 1988 Mar;43(3):283-9.
