Decreased Clearance of Phenytoin with Cimetidine
Authors: GARY J. ALGOZZINE
Journal: Annals of Internal Medicine (1981)

Letters and Corrections1 August 1981Decreased Clearance of Phenytoin with CimetidineGARY J. ALGOZZINE, B.S., RONALD B. STEWART, M.S., PHILLIP K. SPRINGER, M.D.GARY J. ALGOZZINE, B.S.Search for more papers by this author, RONALD B. STEWART, M.S.Search for more papers by this author, PHILLIP K. SPRINGER, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-95-2-244_2 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptTo the editor: Cimetidine has been shown to decrease the metabolism of a number of drugs, namely, diazepam (1), chlordiazepoxide (2), oral anticoagulants (3), theophylline (4), and most recently propranolol (5). Inhibition of hepatic microsomal enzyme systems, specifically P-450 hydroxylation reactions are likely responsible along with decreased liver blood flow. Glucuronidation reactions are spared because lorazepam and oxazepam are unaffected by concomitant Cimetidine therapy (6).Recently, we observed another important interaction in which Cimetidine likely inhibited phenytoin levels.A 31-year-old white woman was treated with Dilantin, 100 mg three times daily, for a seizure disorder secondary to trauma. After approximately...References1. KLOTZREIMANN UL. Delayed clearance of diazepam due to Cimetidine. N Engl J Med. 1980;302:1012-4. CrossrefMedlineGoogle Scholar2. DESMONDRASHMISCHENKER PVS. Cimetidine impairs elimination of chlordiazepoxide (Librium) in man. Ann Intern Med. 1980;93:266-8. LinkGoogle Scholar3. SERLINSIBEONMOSSMAN MRS. Cimetidine: interaction with oral anticoagulants in man. Lancet. 1979;2:317-9. CrossrefMedlineGoogle Scholar4. JACKSONPOWELLWANDELLBENTLEYDORR JJMJR. Cimetidine-theophylline interaction. Pharmacologist. 1980;22:231. Google Scholar5. FEELYWILKINSONWOOD JGA. Reduction of liver blood flow and propranolol metabolism by Cimetidine. N Engl J Med. 1981;304(12):692-5. CrossrefMedlineGoogle Scholar6. PATWARDHANYARBOROUGHDESMONDJOHNSONSCHENKERSPEEG RGPRSK. Cimetidine spares the glucuronidation of lorazepam and oxazepam. Gastroenterology. 1980;79:912-6. CrossrefMedlineGoogle Scholar7. GUGLERMANIONAZARNOFF RCD. Phenytoin: pharmacokinetics and bioavailability. Clin Pharmacol Ther. 1976;19:135-42. CrossrefMedlineGoogle Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: College of Medicine University of Florida Gainesville, FL 32610 PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited ByDosing and Therapeutic Monitoring of Phenytoin in Young Adults After NeurotraumaDisposition, elimination, and bioavailability of phenytoin and its major metabolite in horsesDrug Interactions with Agents Used in the Treatment of CNS DisordersAntiepileptic drug therapy: Clinical laboratory significanceOmeprazole has no effect on acetaminophen kinetics in the ratEffect of concomitant administration of cimetidine and ranitidine on the pharmacokinetics and electrocardiographic effects of terfenadineReview: interactions between H2-antagonists and non-steroidal anti-inflammatory drugsInhibition of Carbamazepine and Phenytoin Metabolism by Nafimidone, a New Antiepileptic DrugDrugs other than H2-receptor antagonists as clinically important inhibitors of drug metabolism in vivoThe Hepatic and Renal Mechanisms of Drug Interactions with CimetidineAntiepileptic drug toxicity: Definition and mechanism of actionEffect of cimetidine on digoxin disposition in peptic ulcer patientsOmeprazole inhibits oxidative drug metabolismUsefulness and safety of cimetidine in patients receiving mexiletine for ventricular arrhythmiaInteractions Between Anticonvulsants and Other Commonly Prescribed DrugsCimetidine-drug interactionsEffect of cimetidine on the pharmacokinetics and pharmacodynamics of quinidineEffect of Cimetidine on Phenytoin Serum LevelsReview of Cimetidine Drug InteractionsReduction in phenytoin clearance caused by cimetidineDrug Interactions and Reactions UpdateCimetidine as an Inhibitor of Drug Metabolism: Therapeutic Implications and Review of the Literature 1 August 1981Volume 95, Issue 2Page: 244-245KeywordsAnticoagulantsBlood flowDiazepamDrug metabolismDrugsEnzymesEpilepsyLiver Issue Published: 1 August 1981 PDF DownloadLoading ...