Omeprazole Metronidazole

The DU-MACH study assessed the efficacy of two omeprazole-based triple therapies (omeprazole, amoxicillin, clarithromycin versus omeprazole, metronidazole, clarithromycin) given for 1 week to 149 patients for eradicating H. pylori, healing duodenal ulcers, and preventing ulcer relapse over 6 months after treatment (4). Both regimens achieved high eradication rates (about 90%) and were well tolerated. Adverse effects were similar in the two groups, and included diarrhea, taste disturbance, headache, nausea, and dyspepsia. 

Chloral hydrate Chloramphenicol Cimetidine Ciprofloxacin Clofibrate Danazol Disulfiram Doxycycline Erythromycin Fenofibrate Fluconazole Fluorouracil Fluoxetine Fluvoxamine Gemfibrozil Influenza vaccine Isoniazid Itraconazole Fovastatin Metronidazole Miconazole Moxalactam Neomycin Norfloxacin Ofloxacin Omeprazole Phenylbutazone Piroxicam Propafenone Propoyxphene Quinidine Sertraline Sulfamethoxazole Sulfinpyrazone Tamoxifen Testosterone Vitamin E Zafirlukast... 

BSS 525 mg four times a day + metronidazole 500 mg four times a day + tetracycline 500 mg four times a day + omeprazole 20 mg twice a dayd... 

Omeprazole 40 mg twice Bismuth subsalicyl- Metronidazole Tetracycline 500 mg four... 

III. Eradication of Helicobacter pylori C. This microorganism plays an important role in the pathogenesis of chronic gastritis and peptic ulcer disease. The combination of antibacterial drugs and omeprazole has proven effective. In case of intolerance to amoxicillin (p. 270) or clarithromycin (p. 276), metronidazole (p. 274) can be used as a substitute. Colloidal bismuth compounds are also effective however, the problem of heavy-metal exposure compromises their long-term use. 

Amiodarone Benzodiazepines Chloramphenicol Cimetidine Disulfiram Ethanol (acute ingestion) Fluconazole Isoniazid Metronidazole Miconazole Omeprazole Phenacemide Phenylbutazone Succinimides Sulfonamides Trimethoprim Valproic acid Salicylates Tricyclic antidepressants Valproic acid... 

Drugs that may affect tacrolimus include nephrotoxic agents (aminoglycosides, amphotericin B, cisplatin, cyclosporine), antifungals, bromocriptine, calcium channel blockers, cimetidine, clarithromycin, danazol, diltiazem, erythromycin, methylprednisolone, metoclopramide, carbamazepine, phenobarbital, phenytoin, rifamycins, cisapride, chloramphenicol, metronidazole, nefazodone, omeprazole, protease inhibitors, macrolide antibiotics, fosphenytoin, and St. John s wort. 

Clarithromycin 500 mg twice daily plus metronidazole 400 mg twice daily plus omeprazole 20 mg twice daily (or lansoprazole 30 mg twice daily or pantoprazole 40 mg twice daily or rabeprazole 20 mg twice daily or ranitidine bismuth citrate... 

Drugs that may inhibit cytochrome P450 metabolism of other drugs include amiodarone, androgens, atazanavir, chloramphenicol, cimetidine, ciprofloxacin, clarithromycin, cyclosporine, delavirdine, diltiazem, diphenhydramine, disulfiram, enoxacin, erythromycin, fluconazole, fluoxetine, fluvoxamine, furanocoumarins (substances in grapefruit juice), indinavir, isoniazid, itraconazole, ketoconazole, metronidazole, mexile-tine, miconazole, nefazodone, omeprazole, paroxetine, propoxyphene, quinidine, ritonavir, sulfamethizole, verapamil, voriconazole, zafirlukast, and zileuton. 

For the eradication of Helicobacter pylori in peptic ulceration, omeprazole may be combined with antibacterials in dual or triple therapy. Effective triple therapy regimens include omeprazole 20 mg twice daily combined with amoxycillin 500 mg and metronidazole 400 mg, both three times daily clarithromycin 500 mg and metronidazole 40 mg (or tinidazole 500 mg) both twice daily or with amoxycillin 1 g and clarithromycin 500 mg both twice daily. These regimens are given for 1 week. Dual therapy regimens, such as omeprazole 40 mg daily with either amoxycillin 750 mg to 1 g twice daily or clarithromycin 500 mg three times daily, are less effective and must be given for 2 weeks. Omeprazole alone may be continued for a further 4r-8 weeks [1]. 

Alcohol should be avoided during furazolidone and metronidazole therapy. Toxic psychosis has been seen in patients under treatment with furazolidone. Metronidazole should be used with caution when coadministering with warfarin, phenytoin, lithium, omeprazole, and phenobarbital. The coadministration of pentamidine with drugs toxic to the kidney should be avoided. 

The MACH-2 study has assessed the role of omeprazole in triple therapy in 539 patients with duodenal ulcers associated with H. pylori (3). The addition of omeprazole resulted in significantly higher eradication rates (over 90%) than antibiotics alone (amoxicillin plus clarithromycin about 25% clarithromycin plus metronidazole 70%), and reduced the impact of primary resistance to metronidazole. About one-third of the patients who took amoxicillin reported diarrhea/loose stools. The frequency of taste disturbance was dose-dependent with clarithromycin. Increased liver enzymes were more commonly reported in those taking metronidazole. The addition of omeprazole did not increase the frequency of reported adverse effects. 

Ranitidine 300 mg bd and omeprazole 20 mg bd have been compared as components of triple therapies (combining them with either amoxicillin plus clarithromycin or amoxicillin plus metronidazole) in 320 patients with H. pylori (5). Omeprazole and ranitidine combined with two antibiotics for 1 week were equally effective in eradicating H. pylori. This result questions the role of profound acid suppression in eradication. There was no difference in the reported adverse effects, which included nausea, vomiting, diarrhea, metallic taste, skin rashes, and headache. 

Quadruple therapy (omeprazole, amoxicUhn, roxithromycin, and metronidazole for 1 week) has been studied in an open trial in 169 patients with H. pylori (8). This regimen achieved an eradication rate of 92%. It was also beneficial in patients infected with pretreatment resistant strains to the antibiotics, in which cases the eradication rates achieved (over 90%) were similar to eradication rates in patients infected with sensitive strains. Compliance was good and there was only one serious adverse effect, anaphylaxis, probably due to amoxicillin. Frequent adverse effects were abdominal distension (10%), glossitis (9%), and diarrhea (8%). 

Pseudomembranous colitis has been reported in an 86-year-old woman with non-ulcer dyspepsia a few days after she had taken triple eradication therapy (omeprazole 20 mg bd, metronidazole 400 mg tds, and clarithromycin 500 mg bd) she recovered after treatment with oral vancomycin (14). 

Triple therapy with bismuth plus amoxicillin and metronidazole for 2 weeks has been compared with dual therapy with omeprazole plus amoxicillin for 2 weeks in 126 patients over the age of 60 years, who were H. pylori positive and had functional dyspepsia (16). Eradication rates were similar in the two groups 2 months after the end of therapy (66% with triple therapy and 64% with dual therapy), and there was a significant reduction in dyspeptic symptoms in patients... 

The effect of adding adherence-enhancing measures to triple therapy with omeprazole plus amoxicillin and metronidazole for 10 days has been studied in 119 Australian patients with H. pylori infection (17). The adherence-enhancing measures were ... 

Gschwantler M, Dragosics B, Schutze K, Wurzer H, Hirschl AM, Pasching E, Wimmer M, BQimpfinger M, Oberhuber G, Brandstatter G, Hentschel E, Weiss W. Famotidine versus omeprazole in combination with clarithromycin and metronidazole for eradication of Helicobacter pylori—a randomized, controlled trial. Aliment Pharmacol Ther 1999 13(8) 1063-9. 

In the eradication of Helicobacter pylori, metronidazole plus bismuth is effective, but causes more adverse effects than omeprazole plus amoxicillin plus either clarithromycin or metronidazole. 

GQ is 33-year-old alcoholic who is placed on metronidazole, clarithromycin, and omeprazole for a recently diagnosed peptic ulcer. A urease breath test is positive for H. pylori. His other medications include ibuprofen, lisinopril, and meclizine. Which of the following is most likely to interact with GQ s metronidazole ... 

Omeprazole 40 mg twice daily Bismuth subsalicylate 525 mg Metronidazole 250-500 mg Tetracycline 500 mg four times daily... 

Omeprazole amoxicillin + clarithromycin or tetracycline HCL + metronidazole + bismuth subsalicylate... 

A 74-year-old woman who had been taking disopyramide 200 mg twiee daily for 7 years eollapsed with ventrieular fihrillation 6 days after starting to take omeprazole 40 mg, metronidazole 800 mg and elarithromyein 500 mg daily. After sueeessful resuseitation, her QTe interval, which had never previously been above 440 milliseconds, was found to have risen to 625 milliseeonds. Her disopyramide plasma level was also elevated (4.6 mierograms/mL) and the half-life was markedly prolonged (40 hours). The QTc interval normalised as her plasma disopyramide levels fell A 76-year old woman taking disopyramide developed torsades de pointes when given clarithromycin 200 mg twice daily. Hypokalaemia (potassium 2.8 mmol/L) probably contributed to this ease. ... 

Thirty-four healthy subjects were randomised to receive a triple therapy capsule Helizide (containing bismuth biskalcitrate 140 mg, metronidazole 125 mg, and tetracycline 125 mg) at a dose of three capsules four times daily with or without omeprazole 20 mg twice daily for 6 days. Omeprazole increased the maximum serum levels and AUC of bismuth by about threefold. However, the maximum serum level achieved was 25.5 micrograms/L, which was still well below 50 micrograms/L, a level reported to be highly unlikely to cause toxicity. The authors also state that in clinical trials of Helizide with omeprazole for 10 days in several hundred patients, no patient showed signs of encephalopathy, a notable toxic adverse effect of bismuth. ... 

Spenard J, Aumais C, Massicotte J, Tremblay C, Lefebvre M. Influence of omeprazole on bioavailability of bismuth following administration of a triple capsule of bismutii biskalcitrate, metronidazole, and tetracycline. J Clin Pharmacol (2004) 44, 640-5. 

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