Drug interaction, omeprazole

Andersson T. Omeprazole drug interaction studies. Clin Pharmacokinet 1991 21 195-212. 

While generally not of major concern, omeprazole may inhibit the metabolism of warfarin, diazepam, and phenytoin lansoprazole may decrease theophylline concentrations. Drug interactions with omeprazole are of particular concern in patients who are considered slow metabolizers, as are approximately 3% of the Caucasian population. Unfortunately, it is unclear which patients have the polymorphic gene variation that makes them slow metabolizers.17 The metabolism of esomeprazole may also be altered in patients with this polymorphic gene variation. Patients on potentially interacting drugs should be monitored for development of drug-related problems. 

Assess for potential drug interactions whenever there is a change in the patient s medications, particularly for patients taking cimetidine, omeprazole, or sucralfate. 

Vitamin B12 generally is well tolerated and exhibits minimal adverse effects. Injection-site pain, pruritus, rash, and diarrhea have been reported. Drug interactions have been observed with omeprazole and ascorbic acid that decrease oral absorption. 

As an inhibitor of CYP3A4 and CYP2C9, the potential for drug-drug interactions with atazanavir is great (Tables 49-3 and 49-4). Atazanavir AUC is reduced by 76% when combined with omeprazole thus, the combination is to be avoided. In addition, co-administration of atazanavir with other drugs that inhibit UGT1A1, such as indinavir and irinotecan, is contraindicated because of enhanced toxicity. Tenofovir and efavirenz should not be -administered with atazanavir unless ritonavir is added to boost levels. 

Saquinavir is subject to extensive first-pass metabolism by CYP3A4 and functions as a CYP3A4 inhibitor as well as a substrate thus, there are many potential drug-drug interactions (Table 49-4). A decreased dose of saquinavir is recommended when -administered with nelfinavir. Increased saquinavir levels when -administered with omeprazole necessitate close monitoring for toxicities. Digoxin levels may increase if co administered with saquinavir and should therefore be monitored. Liver function tests should be monitored if saquinavir is -administered with delavirdine or rifampin. There is no evidence of human teratogenicity from saquinavir there is short-term safety data for both mother and infant. 

Drug Interactions Gemfibrozil Niacin Erythromycin Cholestyramine Digoxin Cimetidine/ranitidine/ omeprazole Rifampicin Warfarin Itraconazole Gemfibrozil Niacin Erythromycin Propranolol Digoxin Warfarin Antacids Colestipol Digoxin Erythromycin Oral contraceptives Fibrates Niacin Azole antifungals... 

Omeprazole (Prilosec) was the original PPI this drug is now joined by esomeprazole (Nexium), lansoprazole (Prevacid), pantoprazole (Protonix), and rabeprazole (AcipHex) (see Table 27-2). All of these drugs are similar, with selection often depending on cost, availability, and the drug interaction potential of each agent.15 Likewise, nonprescription forms of certain PPIs are now available, and these forms offer a convenient,... 

Pantoprazole-sodium has a lower variability in pharmacokinetics compared with omeprazole, particularly with respect to bioavailability. The pharmacokinetics of pantoprazole-sodium are almost the same in patients with gastrointestinal diseases and those with renal failure, and in the elderly, so that no dose adjustment is required. In addition, pantoprazole-sodium has a low potential for drug-drug interaction, which is a considerable benefit because many patients who require pantoprazole are elderly and are receiving co-medications [13]. 

Drug interactions See omeprazole Pregnancy category B Lactation Probably safe Relative cost Oral -, i.v. - ... 

P450, or inducing specific isoforms of this enzyme system. However, drug interactions involving these isoenzymes and omeprazole or lansoprazole are uncommon and generally appear to be clinically unimportant. Pantoprazole seems to have a lower drug interaction potential than either omeprazole or lansoprazole. 

Yin OQP, Tomlinson B, Waye MMY, Chow AHL, Chow MSS. Pharmacokinetics and herb-drug interactions experience with Ginkgo biloba and omeprazole. Pharmacogenetics 2004 14 841-850. 

Omeprazole inhibits the actions of cytochrome P450, which may result in drug interactions. 

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