Cimetidine interactions

Henauer, S.A. and Hollister, T.E. (1984) Cimetidine interaction with imipramine and nortriptyline. Clin Pharmacol Ther 35 183—187. 

Cimetidine overdose should be treated with gastric lavage, emesis induction as an early measure, and should be followed by supportive and symptomatic treatment. Cimetidine interacts with antimuscarinics, antacids, sucralfate, antiarrhythmics, antiepileptics, antidiabetics, and alcohol.173... 

MJ Serlin, S Moisman, RG Sibeon. Cimetidine Interactions with oral anticoagulants in man. Lancet 2 317, 1979. 

Serhn MJ, Sibeon RG, Mossman S, Breckenridge AM, WiUiams JR, Atwood JL, WUloughby JM. Cimetidine interaction with oral anticoagulants in man. Lancet 1979 2(8138) 317-19. 

Curry SH, DeVane CL, Wolfe MM. Cimetidine interaction with amitriptyline. Eur J Chn Pharmacol 1985 29(4) 429-33. 

Kirch W, Janisch HD, Qhnhaus EE, van Peer A. Cisapride-cimetidine interaction enhanced cisapride bioavailability and accelerated cimetidine absorption. Ther Drug Monit 1989 11(4) 411-14. 

Li G, Treiber G, Klotz U. The ibuprofen-cimetidine interaction Stereochemical considerations. (1989) 1, 11-17. 

Forsyth DR, Jayasinghe KSA, Roberts CJC. Do nizatidine and cimetidine interact with ibuprofen EurJ Clin Pharmacol (1988) 35, 85-8. 

The lidocaine/cimetidine interaction is well studied but controversial. It is confused by the differences between the studies (healthy subjects, patients with different diseases, different modes of drug administration, etc). A fall in the clearance of lidoeaine (15% or more) and a resultant rise in the serum levels should be looked for if eimetidine is used, but a clinically significant alteration may not occur in every patient. It may possibly be of less importance in patients following a myocardial infarction because of the increased amounts of alpha-l-acid glycoprotein, which alters the levels of bound and free lidoeaine. Monitor all patients closely for evidence of toxicity and, where possible, check serum lidoeaine levels regularly. A reduced infusion rate may be needed. Ranitidine would appear to be a suitable alternative to eimetidine. See also Anaesthetics, local -i- H2-receptor antagonists , p.l 11. 

Cimetidine binds with the cytochrome P450 isoenzymes and inhibits oxidative metabolism in the liver. Although cimetidine is considered to be a general inhibitor, it exhibits a degree of specificity for certain isoenzymes such as CYP1A2 and CYP2C19. These isoenzymes are principally involved in the metabolism ofR-warfarin and not S-warfarin (see metabolism of the coumarins , (p.358), for more detail). Thus, the interaction between warfarin and cimetidine has been found to be stereoselective (i.e. cimetidine interacts with theR-isomer but not with theS-isomer). " Because R-warfarin is the less active isomer, and the pharmacokinetic interaction is not marked, the interaction is generally modest. 

Hetzel D, BirkettD, Miners J. Cimetidine interaction with warfarin. Lancet (1979) ii, 639. 

Toon S, Hopkins KJ, Garstar F Diquet B, Gill TS, Rowland ML The war rin-cimetidine interaction stereochemical considerations. BrJCZmPhannacoZ (1986) 21,245-6. 

Telerman-TopetN, Duret ME, Co C. Cimetidine interaction with carbamazepine. Arm In-temMed( 9 ) 94,544. 

Hetzel DJ, Bochner F, Hall ike JF, SheannanDJC, Hann CS. Cimetidine interaction with... 

Information appears to be limited to this report but it is consistent with the way cimetidine interacts with many other drugs. Ranitidine, and possibly other H2-receptor antagonists such as famotidine or nizatidine, which do not inhibit liver enzymes, would seem to be preferable and safer alternatives however, this needs confirmation. 

Abemethy DR, Todd EL. Doxepin-cimetidine interaction increased doxepin bioavailability... 

Abemethy DR, Greenblatt DJ, Shader RI. Imipramine-cimetidine interaction impairment of clearance and enhanced absolute bioavailability. J Pharmacol Exp Ther 9ZA) 229, 702-705. 

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