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Addition of metronidazole to rabeprazole-amoxicillin-clarithromycin regimen for Helicobacter pylori infection provides an excellent cure rate with five-day therapy.

BACKGROUND: New triple therapy for eradication of Helicobacter pylori based on a proton pump inhibitor (PPI) provides a cure rate of approximately 90% with few adverse effects. Recently, a PPI-based quadruple therapy, which consists of a PPI plus bismuth-based triple therapy for 7 days, has been studied, and a sufficient eradication rate has been achieved. However, a shorter duration results in improved compliance. In this study, newly developed short-term, simple twice-daily quadruple therapy consisting of rabeprazole, amoxicillin, clarithromycin, and metronidazole (RACM) was compared with a PPI-based triple-therapy regimen for eradication of H. pylori. PATIENTS AND METHODS: This study was designed as a randomized open, prospective single-center study. Of a total of 105 H. pylori-positive patients, 55 received the RACM regimen for 5 days (rabeprazole, 10 mg bid; amoxicillin, 750 mg bid; clarithromycin, 200 mg bid; and metronidazole, 250 mg bid), and 50 received the RAC regimen for 5 days (rabeprazole, 10 mg bid; amoxicillin, 750 mg bid; and clarithromycin, 200 mg bid). Cure of the infection was assessed by HpSA (H. pylori stool antigen immunoassay) 1 month after completion of therapy. RESULTS: The rates of eradication of H. pylori by RACM versus RAC were 94.5% (95% CI, 85-99) versus 80.0% (95% CI, 66-90) by intention-to-treat analysis; 98.1% (95% CI, 90-100) versus 87.0% (95% CI, 74-95) by all-patients-treated analysis; and 98.1% (95% CI, 90-100) versus 86.7% (95% CI, 73-95) by per-protocol analysis. No major adverse effects were reported, and 98.0% of patients reported complete compliance. CONCLUSIONS: The simple twice-daily and short-term quadruple regimen for only 5 days provided an excellent eradication rate. Compliance with the regimen was high, and serious adverse effects were few. Therefore, the RACM regimen can be considered as safe and effective.

2-Pyridinylmethylsulfinylbenzimidazoles↗

A prospective, randomized study of quadruple therapy and high-dose dual therapy for treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin.

BACKGROUND AND AIM: Failure of primary anti-H. pylori therapy results in a high rate of antimicrobial resistance. Here, we investigated the efficacy of high-dose dual therapy and quadruple therapy as salvage treatments for eradication of H. pylori resistant to both metronidazole and clarithromycin. PATIENTS AND METHODS: Patients with at least one treatment failure and infected with H. pylori resistant to both metronidazole and clarithromycin, were randomized to receive either omeprazole 4 x 40 mg and amoxicillin 4 x 750 mg; or omeprazole 2 x 20 mg, bismuthcitrate 4 x 107 mg, metronidazole 4 x 500 mg and tetracycline 4 x 500 mg. Both regimens were given for 14 days. In cases of persistent infection, a cross-over therapy was performed. RESULTS: Eighty-four patients were randomized. Cure of H. pylori infection was achieved in 31 patients after dual therapy and in 35 patients after quadruple therapy (per protocol: 83.8% (95% CI, 67.9-93.8) and 92.1% (95% CI, 78.6-98.3), respectively (p=0.71); intention to treat: 75.6% (95% CI: 59.7-87.6) and 81.4% (95% CI: 66.6-91.6), respectively (p=0.60)). Cross-over therapy was performed in six of nine patients, four of whom were cured of the infection. CONCLUSION: Both high-dose dual therapy and quadruple therapy are effective in curing H. pylori infection resistant to both metronidazole and clarithromycin in patients who experienced previous treatment failures.

Adult↗

Effect of omeprazole on the distribution of metronidazole, amoxicillin, and clarithromycin in human gastric juice.

BACKGROUND & AIMS: The mechanism by which antimicrobial therapy against Helicobacter pylori is enhanced by acid suppression is unknown. The aim of this study was to investigate the effect of omeprazole on gastric juice, plasma, and saliva concentrations of metronidazole, amoxicillin, and clarithromycin. METHODS: Single doses of antibiotic were administered intravenously to 24 healthy men (each antibiotic to 8 subjects) while taking placebo or omeprazole. Antibiotic concentrations were measured in gastric juice, plasma, and saliva. The pharmacokinetic parameters gastric clearance and gastric transfer fraction were calculated for each antibiotic. RESULTS: In the omeprazole group compared with the placebo group, mean maximum antibiotic gastric juice concentrations (in milligram per liter) of metronidazole decreased from 33.6 to 8.3 (P = 0.0001), whereas those of clarithromycin were unchanged, and those of amoxicillin increased from 0.13 to 0.68 (P = 0.02). Omeprazole increased salivary concentrations of metronidazole (P = 0.02) but had no effect on clarithromycin concentrations (no amoxicillin was detectable in saliva). CONCLUSIONS: Omeprazole decreases the intragastric concentrations of metronidazole by reducing acid secretion and increases intragastric concentrations of amoxicillin partly by reducing gastric juice volume. Novel pharmacokinetic parameters have been described that provide an insight into the mechanisms underlying drug transfer across the blood-stomach barrier.

Adult↗

[Antibiotics, purpura and ulcers: a leukocytoclastic vasculitis after clarithromycin].

HISTORY AND CLINICAL FINDINGS: A 47- year-old woman presented with palpable purpura of both lower limbs after taking six tablets of clarithromycin for pneumonia. INVESTIGATIONS: Apart from mild microhematuria there were no other signs of organ involvement. Histology of a skin biopsy revealed a hypersensitivity vasculitis. TREATMENT AND COURSE: A hypersensitivity vasculitis due to clarithromycin was the cause of the purpura. The course of this hypersensitivity vasculitis was severe and protracted over weeks with formation of deep ulcerative skin lesions. CONCLUSION: Clarithromycin may be the cause of a hypersensitivity vasculitis: often the course of the disease is mild, but it may also lead to severe local complications. The diagnosis of hypersensitivity vasculitis can be made in a patient over 16 years of age if there is the combination of a triggering substance, purpura and leukocytoclastic vasculitis. The most important step is immediate withdrawal of the causative agent. A beneficial effect of treatment with steroids on prognosis is not proven.

Anti-Bacterial Agents↗

A prospective controlled multicentre study of clarithromycin in pregnancy.

Clarithromycin is a relatively new macrolide antibiotic with an action spectrum similar to that of erythromycin. Its main indications for use are for upper and lower respiratory and skin and soft tissue infections. Little is known about its safety in pregnancy, although animal reproductive studies found an increased rate of cardiovascular anomalies, cleft palate, and embryonic loss. Human data, limited to case reports and one small uncontrolled study, cannot allow evidence based counseling of pregnant women who were exposed to the drug before finding out they were pregnant. Pregnant women who had been counseled on the use of clarithromycin by five centers, were matched for age, smoking, and alcohol use with a control group of pregnant women who were exposed to nonteratogenic antibiotics. A total of 157 women were followed up. Of these, 122 were exposed to the drug in the first trimester. There were no significant differences found between the two groups in the rates of major and minor malformations; 2.3 versus 1.4% for major (p = 0.86) and 5.4 versus 4.9% for minor (p = 0.96). Spontaneous abortion rates in the exposed group was significantly different, higher (14%) than in the control group (7%) (p = 0.04). This first prospective controlled study of exposure to clarithromycin in pregnancy suggests that this agent does not increase the rate of major malformations above the baseline risk of 1-3%. The higher rate of reported spontaneous abortions, although still within the expected baseline rate, may warrant further study.

Anti-Bacterial Agents↗

Omeprazole combined with amoxicillin and clarithromycin in the eradication of Helicobacter pylori in children with gastritis: A prospective randomized double-blind trial.

OBJECTIVES: The aim of this multicenter prospective, randomized, double-blind study was to assess the efficacy of the combination of omeprazole, amoxicillin, and clarithromycin (OAC) for the treatment of Helicobacter pylori gastritis in children. STUDY DESIGN: Seventy-three children with dyspeptic symptoms were included in the trial (mean age 10.8 years; range, 3.3 to 15.4). Patients were randomized to receive OAC or amoxicillin and clarithromycin (AC) for 7 days. H pylori status was assessed before and 4 weeks after eradication treatment, by use of the carbon 13-labeled urea breath test. RESULTS: In intent-to-treat analysis (n = 63), eradication rates were 74.2% (95% CI, 58.7 to 89.6) in the OAC group and 9.4% (95% CI, 0 to 19.5) in the AC group. In per-protocol analysis (n = 53), the eradication rate increased to 80% (95% CI, 64.3 to 95.7), remaining significantly higher than in AC group (10.7%; 95% CI, 0 to 22.2). Resistance of strains to clarithromycin was rare (3/39 = 7.7%) and was not associated with failure of treatment. Adverse events were reported in 24.6% of patients and remained mild. CONCLUSION: This study shows that 1-week OAC triple therapy results in successful eradication of H pylori in 75% of children with gastritis.

Adolescent↗

Comparative effects of moxifloxacin and clarithromycin on the normal intestinal microflora.

Twelve healthy male subjects age range 24-40 y participated in the investigation. The trial was divided into 2 35-d periods. The 2 treatment regimens were: (i) 1 x 400 mg moxifloxacin tablet in the morning and 1 placebo tablet in the evening for 7 d; and (ii) 1 x 500 mg clarithromycin tablet in the morning and 1 x 500 mg clarithromycin tablet in the evening for 7 d. Each subject received firstly I treatment regimen and secondly the other treatment regimen. The wash-out period was 6 weeks between the two treatment regimens. Moxifloxacin caused significant decreases of enterococci and enterobacteria during the administration period while the numbers of staphylococci, streptococci, Bacillus and Candida were not affected. No impact on peptostreptococci, lactobacilli, Veillonella, Bacteroides or fusobacteria was observed, while bifidobacteria and clostridia decreased during moxifloxacin administration. The microflora was normalized after 35 d. Clarithromycin caused significant reduction of Escherichia coli while the numbers of enterococci, Enterobacter, Citrobacter, Klebsiella and Pseudomonas increased markedly. No significant changes in the numbers of staphylococci, streptococci, Bacillus and Candida were noticed. In the anaerobic microflora bifidobacteria, lactobacilli and clostridia were suppressed, while no changes in peptostreptococci, Veillonella, Bacteroides and fusobacteria were found. The microflora was normalized in all volunteers after 35 d.

Administration, Oral↗

BLT-D (clarithromycin [Biaxin], low-dose thalidomide, and dexamethasone) for the treatment of myeloma and Waldenström's macroglobulinemia.

Multiple myeloma remains incurable. Despite the pursuit of various chemotherapeutic approaches, little improvement in outcome has been made in the last 30 years. Thalidomide, dexamethasone, and clarithromycin are oral, nonmyelosuppressive agents, each with reported single agent activity against myeloma. We evaluated a regimen of clarithromycin (Biaxin), low-dose thalidomide and dexamethasone (BLT-D) in patients with previously untreated or treated multiple myeloma or Waldenström's macroglobulinemia. Patients were initially given clarithromycin 500 mg twice daily, thalidomide 50-200 mg daily, and dexamethasone 40 mg weekly until disease progression. Minimum response was defined as > 50% reduction in monoclonal immunoglobulin or light chain levels in serum or urine. Response, toxicity, and survival were determined on an evaluable and/or intent-to-treat basis. Of the 50 patients available for analysis, 92% remain alive and 64% remain on treatment with a median and mean duration of treatment of 7 and 8 months, respectively. Overall, 93% of evaluable patients responded to BLT-D, including 13% complete remissions, 40% near complete responses, 13% major responses, and 27% partial responses. Minimal drug resistance was initially encountered. Neurotoxicity, although usually mild to moderate, was the primary reason for treatment discontinuation. Only four patients died, including three sudden deaths in patients with severe cardiopulmonary disease. It appears that BLT-D is a highly effective, nonmyelosuppressive regimen for myeloma. Caution should be exercised when using thalidomide, alone or in combination, in patients with a preexisting tendency to thromboses, severe cardiopulmonary disease, or neurologic dysfunction.

Aged↗

Efficacy and safety of clarithromycin as treatment for Mediterranean spotted fever in children: a randomized controlled trial.

Fifty-one children with Mediterranean spotted fever (MSF) were randomized to receive either clarithromycin, 15 mg/kg/day orally in 2 divided doses, or chloramphenicol, 50 mg/kg/day orally in 4 divided doses, for 7 days. Mean time to defervescence was 36.7 h in the clarithromycin group and 47.1 h in the chloramphenicol group (P=.047). Clarithromycin could be an acceptable therapeutic alternative to chloramphenicol and to tetracyclines for children aged <8 years with MSF.

Anti-Bacterial Agents↗

Clarithromycin versus azithromycin in the treatment of Mediterranean spotted fever in children: a randomized controlled trial.

We conducted an open-label randomized controlled trial to compare the efficacy and safety of clarithromycin (15/mg/kg/day in 2 divided doses for 7 days) with those of azithromycin (10 mg/kg/day in 1 dose for 3 days) in the treatment of children with Mediterranean spotted fever. Until now, there has not been a gold-standard therapy for this rickettsial disease in children. Eighty-seven children were randomized to receive 1 of the 2 drugs. The mean time to defervescence (+/- standard deviation) was 46.2+/-36.4 h in the clarithromycin group and 39.3+/-31.3 h in the azithromycin group. These differences were not statistically significant and both drugs were equally well-tolerated. Clarithromycin and azithromycin could be acceptable therapeutic alternatives to chloramphenicol and tetracyclines for children aged < or =8 years with Mediterranean spotted fever. Azithromycin, because it has a long half-life, offers the advantages of administration in a single daily dose and a shorter duration of therapy, which could increase compliance in children.

Adolescent↗

Thrice-weekly clarithromycin-containing regimen for treatment of Mycobacterium kansasii lung disease: results of a preliminary study.

We initiated a prospective trial of an intermittent clarithromycin-containing regimen for the treatment of patients with Mycobacterium kansasii lung disease. Eighteen patients (10 men and 8 women) with M. kansasii lung disease received a regimen consisting of 500-1000 mg of clarithromycin, 25 mg/kg ethambutol, and 600 mg of rifampin 3 times per week. The primary treatment end point was a 12-month period during which sputum cultures were sterile while the patient was receiving therapy. Four male patients were lost to follow-up, but all of the remaining patients successfully completed therapy without significant drug-related adverse events. The mean time (+/- standard deviation [SD]) to sputum conversion was 1.0+/-0.9 months, and the mean duration (+/-SD) of therapy was 13.4+/-0.9 months. No patient who successfully completed therapy had relapsed after a mean (+/-SD) of 46+/-8.0 months. Clarithromycin- and rifampin-containing regimens offer the possibility of effective short-course and intermittent treatment of M. kansasii lung disease.

Anti-Bacterial Agents↗

Randomized, open-label trial of azithromycin plus ethambutol vs. clarithromycin plus ethambutol as therapy for Mycobacterium avium complex bacteremia in patients with human immunodeficiency virus infection. Veterans Affairs HIV Research Consortium.

Disseminated Mycobacterium avium complex (MAC) infection continues to be a common opportunistic infection in patients infected with human immunodeficiency virus (HIV). The optimal therapy for disseminated MAC infection is unclear. We compared azithromycin plus ethambutol with clarithromycin plus ethambutol in the treatment of disseminated MAC infection in HIV type 1-infected patients, examining the frequency of bacteremia clearance, time to clearance, and study drug tolerance after 16 weeks of therapy. Fifty-nine patients for whom blood cultures were positive for MAC were enrolled in the study from 10 university-affiliated Veterans Affairs Medical Centers. Thirty-seven patients were evaluable for determination of quantitative bacteremia and clinical outcomes. Clearance of bacteremia was seen at the final visit in 37.5% of azithromycin-treated patients and in 85.7% of clarithromycin-treated patients (P = .007). The estimated median time to clearance of bacteremia was also significantly different between the two treatment arms: 4.38 weeks for clarithromycin recipients vs. > 16 weeks for azithromycin recipients (P = .0018). Only one isolate developed macrolide resistance during therapy. Abatement of symptoms, other laboratory-evident abnormalities, and adverse effects were similar in the two groups. At the doses used in this study, clarithromycin/ethambutol produced a more rapid resolution of bacteremia than did azithromycin/ethambutol, and clarithromycin/ethambutol was more effective at sterilization of blood cultures after 16 weeks of therapy.

AIDS-Related Opportunistic Infections↗

Clarithromycin-induced mania in two patients with AIDS.

Acute psychosis was observed in two patients with AIDS who were treated with clarithromycin for disseminated Mycobacterium avium complex infection. The psychosis resolved when treatment with clarithromycin was discontinued and recurred when it was resumed. An adverse response to clarithromycin therapy is a rare but curable cause of acute psychosis in patients with AIDS.

AIDS-Related Opportunistic Infections↗

Powerful bactericidal activities of clarithromycin and minocycline against Mycobacterium leprae in lepromatous leprosy.

Thirty-six patients with newly diagnosed lepromatous leprosy were allocated randomly to three groups and treated for 56 days with minocycline (100 mg daily), clarithromycin (500 mg daily), or clarithromycin (500 mg) plus minocycline (100 mg daily). All groups had rapid and remarkable clinical improvement and significant decline of the bacterial and morphologic indices in skin smears during treatment. More than 99% and > 99.9% of the viable Mycobacterium leprae had been killed by 28 and 56 days of treatment, respectively, as measured by inoculation of organisms recovered from skin samples, taken before and during treatment, into the footpads of immunocompetent and nude mice. Clinical improvement and bactericidal activity did not differ significantly among the three groups. Adverse reactions were rare and mild, and no laboratory abnormality was detected during the trial. Both clarithromycin and minocycline displayed powerful bactericidal activities against M. leprae in leprosy patients and may be considered important components of new multidrug regimens for the treatment of multibacillary leprosy.

Adolescent↗

An in-vitro evaluation of the cellular uptake and intraphagocytic bioactivity of clarithromycin (A-56268, TE-031), a new macrolide antimicrobial agent.

Erythromycin base and its 6-0-methyl derivative clarithromycin were actively accumulated 7.3 +/- 1.2-fold and 9.2 +/- 2-fold respectively by human neutrophils in vitro. The intraphagocytic bioactivities of the antimicrobial agents were investigated using the combination of a radioassay, colony counting method and a fluorescence microassay which facilitates the distinction between intracellular bacteriostatic and bactericidal mechanisms. Staphylococcus aureus, Listeria monocytogenes and Legionella micdadei were used as the test intraphagocytic microbial pathogens. Both agents were found to possess intracellular bioactivity for all three species of bacteria with clarithromycin being consistently more active than erythromycin. Under the assay conditions used both agents were bacteriostatic (intracellularly) for S. aureus and Leg. micdadei and bactericidal for List. monocytogenes. Clarithromycin is clearly a potent intraphagocytic antibiotic and potentially superior in this respect to erythromycin.

Adult↗

In-vitro activity of clarithromycin combined with its 14-hydroxy metabolite A-62671 against Haemophilus influenzae.

Clarithromycin and its 14-hydroxy metabolite (A-62671), were tested against 20 strains of Haemophilus influenzae. Minimum inhibitory and bactericidal concentrations of the two compounds alone and in combination were determined in a microbroth system which allowed continuous turbidimetric measurement for the construction of growth curves. MICs of clarithromycin were 2-8 and 1-4 mg/l for A-62671 for the majority of strains. MBCs were identical to or one dilution higher than the respective MICs. Combinations of the two compounds were inhibitory or bactericidal at concentrations that were lower than the MICs or MBCs. On the basis of fractional inhibitory (FIC) or fractional bactericidal (FBC) concentration indices, the interactions between clarithromycin and its metabolite were defined as additive.

Clarithromycin↗

A comparison of the efficacy of azithromycin and clarithromycin in oral therapy of experimental airborne Legionnaires' disease.

The activities of two new macrolides, azithromycin and clarithromycin, were compared in an aerosol-infected guinea-pig model of legionnaires' disease. The results of this study indicate that a low oral dose of azithromycin (3.6 mg/kg) administered once daily gives 100% survival in Legionella pneumophila-infected animals. An eight-fold higher dose of clarithromycin (28.8 mg/kg) given twice-daily was required to achieve the same effect. Similarly, azithromycin was more effective than clarithromycin in preventing pyrexia and in reducing numbers of bacteria and lesions in the lung.

Administration, Inhalation↗

Penetration of clarithromycin and its 14-hydroxy metabolite into middle ear effusion in children with secretory otitis media.

Clarithromycin suspension was given at a dosage of 7.5 mg/kg bd for 7 days to 31 children with secretory otitis media, scheduled for insertion of grommets. The fifth dose was given approximately 2.5 h before myringotomy and aspiration of the middle ear effusion at which time a blood sample also was taken. In addition, in 16 children blood samples were taken at 1, 1.5 and 4 h after the fifth dose. The concentrations of clarithromycin and its active 14-hydroxylated metabolite, in middle ear effusion and serum, were determined by HPLC. Before therapy, at surgery on day 3 and after completion of treatment, nasopharyngeal samples were taken for culture and susceptibility testing. In the middle ear effusions mean concentrations of clarithromycin (2.5 mg/L) and metabolite (1.3 mg/L) were considerably higher than the serum concentrations (1.7 and 0.8 mg/L, respectively). The mean concentrations in middle ear effusion exceeded the MICs for most respiratory pathogens. Complete eradication of Streptococcus pneumoniae, Moraxella catarrhalis and Streptococcus pyogenes from the nasopharynx was achieved after three days of therapy. Approximately 50% of the isolates of Haemophilus influenzae were eradicated from approximately 50% of the patients and the growth of the persisting strains was decreased from abundant or moderate to sparse. Adverse events were mild and transient and were experienced by only two of the 31 children.

Child↗