Mg Of Clarithromycin Research Articles

Therapeutic Effects of Various Initial Combinations of Chemotherapy Including Clarithromycin Against Mycobacterium avium Complex Pulmonary Disease

The objective of this study was to find an optimal initial combination chemotherapy that includes clarithromycin (CAM) for treatment-naive patients with Mycobacterium avium complex (MAC) pulmonary disease, as assessed by microbiological conversion using a Mycobacterium growth indicator tube (MGIT). Thirty-four patients with treatment-naive MAC pulmonary disease (determined using 1997 American Thoracic Society criteria) were evaluated retrospectively. They demonstrated a nodular and bronchiectatic pattern without cavity on high-resolution CT (HRCT) scans. The following three regimens were administered: regimen A (n = 9) consisted of CAM (400 mg/d), ethambutol (EB) [750 mg/d], and rifampicin (RFP) [450 mg/d]; regimen B (n = 12) consisted of CAM (800 mg/d), EB (750 mg/d), and RFP (450 mg/d); and regimen C (n = 13) consisted of CAM (800 mg/d), EB (1,000 mg/d), and RFP (600 mg/d) during the first 2 months followed by a reduction of the dosage of EB from 1,000 to 750 mg/d. Gender, age, BMI, and HRCT scan finding scores were not significantly different among the three groups. Chemotherapy was continued for 18 months. Sputum culture was periodically assessed by MGIT. Culture conversion at 18 months in regimen A (55.6%), which included a daily dosage of 400 mg of CAM (9.5 mg/kg), was significantly inferior to that in regimen B (91.7%), which included daily 800 mg of CAM (17.6 mg/kg; p < 0.05), but regimen B and C (92.3%) showed no between-group difference after > 18 months of chemotherapy. The higher dose of CAM allowed for better culture conversion. Daily combination chemotherapy that includes CAM (800 mg) seems appropriate as an initial treatment against treatment-naive patients with nodular and bronchiectatic MAC pulmonary disease.

Physiologically Based Pharmacokinetic Model of Mechanism-Based Inhibition of CYP3A by Clarithromycin

The prediction of clinical drug-drug interactions (DDIs) due to mechanism-based inhibitors of CYP3A is complicated when the inhibitor itself is metabolized by CYP3Aas in the case of clarithromycin. Previous attempts to predict the effects of clarithromycin on CYP3A substrates, e.g., midazolam, failed to account for nonlinear metabolism of clarithromycin. A semiphysiologically based pharmacokinetic model was developed for clarithromycin and midazolam metabolism, incorporating hepatic and intestinal metabolism by CYP3A and non-CYP3A mechanisms. CYP3A inactivation by clarithromycin occurred at both sites. K(I) and k(inact) values for clarithromycin obtained from in vitro sources were unable to accurately predict the clinical effect of clarithromycin on CYP3A activity. An iterative approach determined the optimum values to predict in vivo effects of clarithromycin on midazolam to be 5.3 microM for K(i) and 0.4 and 4 h(-1) for k(inact) in the liver and intestines, respectively. The incorporation of CYP3A-dependent metabolism of clarithromycin enabled prediction of its nonlinear pharmacokinetics. The predicted 2.6-fold change in intravenous midazolam area under the plasma concentration-time curve (AUC) after 500 mg of clarithromycin orally twice daily was consistent with clinical observations. Although the mean predicted 5.3-fold change in the AUC of oral midazolam was lower than mean observed values, it was within the range of observations. Intestinal CYP3A activity was less sensitive to changes in K(I), k(inact), and CYP3A half-life than hepatic CYP3A. This semiphysiologically based pharmacokinetic model incorporating CYP3A inactivation in the intestine and liver accurately predicts the nonlinear pharmacokinetics of clarithromycin and the DDI observed between clarithromycin and midazolam. Furthermore, this model framework can be applied to other mechanism-based inhibitors.

Short Term Treatment With Clarithromycin Resulting in Colchicine-Induced Rhabdomyolysis

A case of colchicine-induced rhabdomyolysis is reported. A 48 year old African-American male with history of hypertension and chronic gout on colchicine 0.6 mg daily presented with symptoms of a community acquired pneumonia. The patient was started on 500 mg of clarithromycin orally twice daily and represented to the emergency room after 3 days complaining of severe muscle pain. His liver panel showed elevations in the serum aminotransferases; AST 513 mU/ml (nl 15-41) and ALT 182 mU/ml (nl 17-63). His complete blood count showed an elevated white blood cell count of 18,800/ml (nl 4,000-10,000/ml). Urine analysis was positive for myoglobin with no red cells present. Serum creatine kinase (CK) was 22,996 mU/ml (nl 31-221) with a normal troponin I 0.18 (nl <0.4).Investigations confirmed the presence of rhabdomyolysis and discontinuation of colchicine and clarithromycin resulted in resolution of clinical and biochemical features of rhabdomyolysis. By hospital day four, his muscle soreness had improved markedly. His serum CK improved to 3,389 mU/ml (nl 31-221 mU/ml) and serum creatinine improved to 1.5 mg/dl (nl 0.8-1.2). On hospital day five, the patient was discharged on oral anti-hypertensive medication and a ten-day course of doxycycline. Metabolism of colchicine by the cytochrome P450 3A4 system has been previously described, but this is the first published report of colchicine associated rhabdomyolysis secondary to drug metabolism interactions with an antibiotic. A review of medications that are metabolized via the cytochrome 3A4 and A-SLAVED-LIVER (Amiodarone, Simvastatin, Lovastatin, Atorvastatin, Verapamil, Erythromycin, Diltiazem, cLarithromycin, Itraconazole, Voriconazole, colchicinE, Ritonavir) pneumonic was established.

Compliance with and short-term adverse events from clarithromycin versus placebo in patients with stable coronary heart disease: the CLARICOR trial

The randomized placebo-controlled double-blind CLARICOR trial investigated the influence of clarithromycin versus placebo on cardiovascular events and mortality in patients with chronic coronary artery disease (ClinicalTrials.gov NCT 00121550). The trial randomized 2172 patients to 500 mg of clarithromycin daily versus 2200 patients to matching placebo for 14 days. This paper presents protocol-specified analysis of the patient-reported information regarding their compliance and non-serious adverse events during the 14 days of treatment as well as serious adverse events (mortality and hospitalizations) during the first 30 days after randomization. Randomized clinical trial focusing on patient-reported information regarding their compliance and adverse events. Of the randomized patients, 99% reported information regarding their compliance and adverse events. A 100% tablet intake was reported by 90% of the clarithromycin group and by 93.7% of the placebo group. Of the clarithromycin patients, 39.5% reported at least one non-serious adverse event versus 25.1% of the placebo patients (P < 0.001). Gastrointestinal adverse reactions were reported 950 times by 697 patients (32.3%) in the clarithromycin group and 485 times by 390 patients (17.9%) in the placebo group (P < 0.001). No significant differences were seen in other non-serious or serious adverse events during the first month after inclusion. Short-term non-serious adverse events did not explain the previously reported long-term significantly increased mortality associated with clarithromycin. Gastrointestinal adverse reactions are common during clarithromycin administration, but at least half are also seen with a placebo.

Interaction Studies of Tipranavir-Ritonavir with Clarithromycin, Fluconazole, and Rifabutin in Healthy Volunteers

Three separate controlled, two-period studies with healthy volunteers assessed the pharmacokinetic interactions between tipranavir-ritonavir (TPV/r) in a 500/200-mg dose and 500 mg of clarithromycin (CLR), 100 mg of fluconazole (FCZ), or 150 mg of rifabutin (RFB). The CLR study was conducted with 24 subjects. The geometric mean ratios (GMR) and 90% confidence intervals (90% CI; given in parentheses) of the areas under the concentration-time curve (AUC), the maximum concentrations of the drugs in serum (C(max)), and the concentrations in serum at 12 h postdose (Cp12h) for multiple-dose TPV/r and multiple-dose CLR, indicating the effect of TPV/r on the CLR parameters, were 1.19 (1.04-1.37), 0.95 (0.83-1.09), and 1.68 (1.42-1.98), respectively. The formation of the metabolite 14-OH-CLR was decreased by 95% in the presence of TPV, and the TPV AUC increased 66% compared to that for human immunodeficiency virus (HIV)-negative historical controls. The FCZ study was conducted with 20 subjects. The GMR (and 90% CI) of the AUC, C(max), and Cp24h, indicating the effect of multiple-dose TPV/r on the multiple-dose FCZ parameters, were 0.92 (0.88-0.95), 0.94 (0.91-0.98), and 0.89 (0.85-0.92), respectively. The TPV AUC increased by 50% compared to that for HIV-negative historical controls. The RFB study was conducted with 24 subjects. The GMR (and 90% CI) of the AUC, C(max), and Cp12h for multiple-dose TPV/r and single-dose RFB, indicating the effect of TPV/r on the RFB parameters, were 2.90 (2.59-3.26), 1.70 (1.49-1.94), and 2.14 (1.90-2.41), respectively. The GMR (and 90% CI) of the AUC, C(max), and Cp12h of TPV/r and RFB with 25-O-desacetyl-RFB were 4.33 (3.86-4.86), 1.86 (1.63-2.12), and 2.76 (2.44-3.12), respectively. Coadministration of TPV with a single dose of RFB resulted in a 16% increase in the TPV Cp12h compared to that for TPV alone. In the general population, no dose adjustments are necessary for the combination of TPV/r and CLR or FCZ. Combining TPV/r with RFB should be done with caution, while toxicity and RFB drug levels should be monitored. Study medications were generally well-tolerated in these studies.

Effect of Clarithromycin on the Pharmacokinetics of Pranlukast in Healthy Volunteers

Pranlukast is a cysteinyl leukotriene receptor antagonist that has been used to treat bronchial asthma and allergic rhinitis. In vitro data suggest that pranlukast is a substrate of CYP3A4. Thus, the effect of clarithromycin, a potent CYP3A4 inhibitor, on the pharmacokinetics of pranlukast was examined in an open-label, randomized, two-way crossover study in 16 healthy male volunteers. In treatment A, volunteers received a single, 225 mg dose of pranlukast. In treatment B, 200 mg of clarithromycin was administered twice daily for 7 days and a single, 225 mg dose of pranlukast was coadministered on day 7. Blood samples were collected up to 24 hours after treatment, and pranlukast concentrations in the plasma were measured. The geometric mean ratios [GMR] (90% confidence intervals [CIs]) for pranlukast AUC(0-infinity) and C(max) (with/without clarithromycin) were 1.06 (0.91, 1.24) and 1.17 (0.95, 1.45), respectively. In conclusion, clarithromycin and pranlukast could be coadministered without dose adjustment because clarithromycin minimally affected the pharmacokinetics of pranlukast.

Pharmacokinetics of Single- and Multiple-Dose Oral Clarithromycin in Soft Tissues Determined by Microdialysis

The antimicrobial spectrum of clarithromycin renders this antibiotic a frequently used option in the treatment of skin and soft-tissue infections. In most cases, these infections are caused by extracellularly proliferating microorganisms. Thus, clarithromycin concentrations achieved in the interstitial space are considered particularly important for clinical efficacy. In the present study, clarithromycin concentrations in plasma and interstitial-space fluid of subcutaneous adipose tissue and skeletal muscle of six healthy male volunteers were assessed by means of the microdialysis technique after oral single-dose administration of 250 mg and multiple doses of 500 mg of clarithromycin twice a day (b.i.d.). The ratios of the area under the concentration-time curve of free clarithromycin from 0 to 24 h calculated for a single dose of 250 mg (fAUC(0-24)) in interstitial-space fluid to the fAUC(0-24) in plasma were 0.29 +/- 0.17 and 0.42 +/- 0.18 for subcutis and skeletal muscle, respectively. For 500 mg of clarithromycin at the steady state (3 to 5 days of intake twice daily), the fAUC(0-24(b.i.d.)) ratios at the steady state were 0.39 +/- 0.04 and 0.41 +/- 0.19 for subcutis and skeletal muscle, respectively. The half-life was around 2 h after a single dose but increased to approximately 4 h in plasma and tissues after repetitive clarithromycin administration. Based on subsequently performed pharmacokinetic-pharmacodynamic calculations, a dosing regimen of 500 mg b.i.d. may be ineffective in the treatment of soft-tissue infections caused by pathogens with a drug MIC higher than 0.125 mg/liter.

A Better Cure Rate with 800 mg than with 400 mg Clarithromycin Regimens in One-Week Triple Therapy for Helicobacter pylori Infection in Cigarette-Smoking Peptic Ulcer Patients

Background/Aims: In Helicobacter pylori eradication therapy, using a proton pump inhibitor plus amoxicillin and clarithromycin (PPI/AC regimen), the impact of the clarithromycin dose and smoking on efficacy is conflicting. Here, we compared the efficacy of 400 and 800 mg of clarithromycin in the regimen in relation to smoking in patients with peptic ulcer disease. Methods: We studied 601 H. pylori-positive patients with peptic ulcer disease who had received amoxicillin 750 mg and clarithromycin 200 or 400 mg together with lansoprazole 30 mg b.i.d. Results: 305 patients were treated with a regimen containing 400 mg of clarithromycin (C400 group), and 296 patients with a regimen containing 800 mg (C800 group). Overall cure rates between the two groups were not significantly different, but the cure rate in the C800 group was significantly better than that in the C400 group among patients infected with clarithromycin-sensitive strains (p = 0.03). This difference could be attributed to differences among smokers versus non-smokers: the cure rate among smokers in the C800 group (91.0%) was better than that in the C400 group (80.0%, p = 0.003). Conclusions: 800 mg of clarithromycin is recommended in the PPI/AC regimen for patients who smoke and are infected with clarithromycin-sensitive H. pylori.

Sequential Therapy versus Standard Triple-Drug Therapy for Helicobacter pylori Eradication

Antimicrobial resistance has decreased eradication rates for Helicobacter pylori infection worldwide. To determine whether sequential treatment eradicates H. pylori infection better than standard triple-drug therapy for adults with dyspepsia or peptic ulcers. Randomized, double-blind, placebo-controlled trial. Two Italian hospitals between September 2003 and April 2006. 300 patients with dyspepsia or peptic ulcers. (13)C-urea breath test, upper endoscopy, histologic evaluation, rapid urease test, bacterial culture, and assessment of antibiotic resistance. A 10-day sequential regimen (40 mg of pantoprazole, 1 g of amoxicillin, and placebo, each administered twice daily for the first 5 days, followed by 40 mg of pantoprazole, 500 mg of clarithromycin, and 500 mg of tinidazole, each administered twice daily for the remaining 5 days) or standard 10-day therapy (40 mg of pantoprazole, 500 mg of clarithromycin, and 1 g of amoxicillin, each administered twice daily). The eradication rate achieved with the sequential regimen was significantly greater than that obtained with the standard treatment in the intention-to-treat analysis (89% vs. 77%; P = 0.0134; difference, 12% [95% CI, 3% to 20%]), the modified intention-to-treat analysis (91% vs. 78%; P = 0.0022; difference, 13% [CI, 5% to 21%]), and the per-protocol analysis (93% vs. 79%; P = 0.0013; difference, 14% [CI, 6% to 21%]). Sequential therapy was significantly more effective in patients with clarithromycin-resistant strains (89% vs. 29%; P = 0.0034). The incidence of major and minor side effects did not differ between therapy groups (17% in both groups). One patient (0.7%) in the standard therapy group discontinued treatment because of side effects. Follow-up was incomplete in 4.6% and 2.7% patients in the sequential therapy and standard therapy groups, respectively. The results may not be generalizable to other countries. Sequential therapy may be more effective because it includes 1 additional antibiotic (tinidazole) that is not contained in standard therapy. Sequential therapy is statistically significant compared with standard therapy for eradicating H. pylori infection and is statistically significantly more effective in patients with clarithromycin-resistant strains. Side effects are similar with both treatment regimens and are rarely severe enough to cause discontinuation of therapy. ClinicalTrials.gov registration number: NCT00403364.

Clarithromycin-Resistant Genotypes and Eradication of Helicobacter pylori

Three point mutations (A2143G, A2142G, and A2142C) have been involved in Helicobacter pylori clarithromycin resistance. To compare the eradication rates among the different point mutations and the efficacy of triple therapy and a sequential regimen according to genotypic resistance. Post hoc subgroup study from a multicenter, randomized trial. Two hospitals in central and southern Italy between January and December 2001. 156 patients with H. pylori infection. Real-time polymerase chain reaction for assessing clarithromycin resistance; histology, rapid urease test, and 13C-urea breath test at entry and after 4 to 6 weeks. 7-day triple therapy (20 mg of rabeprazole, 500 mg of clarithromycin, and 1 g of amoxicillin) in 75 patients or a 10-day sequential regimen (20 mg of rabeprazole plus 1 g of amoxicillin for 5 days and 20 mg of rabeprazole, 500 mg of clarithromycin, and 500 mg of tinidazole for the remaining 5 days) in 81 patients. All drugs were given twice daily. Helicobacter pylori infection was eradicated in 11 of 23 patients (48%) with the A2143G mutation and in 14 of 15 patients (93%) with either A2142G or A2142C strains (difference, 45 percentage points [95% CI, 15 to 65 percentage points]; P = 0.004). The sequential regimen achieved a higher cure rate than triple therapy in A2143G mutate strains (difference, 49 percentage points [CI, 8 to 72 percentage points]; P = 0.024). The post hoc substudy design may require further confirmation. Other limitations are the accessibility to the tool and the cost of investigations (70 euros per patient). The A2143G mutation seemed to be associated with a very low eradication rate. The sequential regimen achieved a higher cure rate than standard therapy even in patients with these strains.

Macrolide resistance of Streptococcus pneumoniae isolated during long-term macrolide therapy: difference between erythromycin and clarithromycin

Longterm macrolide therapy (LTMT) has been employed as an effective therapy both for diffuse panbronchiolitis in Japan and for cystic fibrosis in European countries. However, effects on antibiotic susceptibility profiles of microorganisms, associated with such long-term administration of antibiotics, are of concern. We retrospectively identified 57 pneumococcal isolates, recovered from the same number of patients receiving either LTMT with 400 mg of clarithromycin daily (CAM group; n = 31) or 600 mg of erythromycin daily (EM group; n = 26) by reviewing the patients' records at Nara Medical University. On analysis, we found that all isolates recovered from the CAM group and 25 of the 26 recovered from the EM group were resistant to EM, showing either an MLSB: or an M phenotype. Interestingly, isolates exhibiting the M phenotype were much less frequent in the CAM group (2 of 31; 6.5%) than in the EM group (15 of 26; 57.7%). No increase in the rate of penicillin resistance was observed in either group. The macrolide resistance profiles of microorganisms may be influenced differently according to differences in the kind of macrolide antibiotics used.

Immunomodulatory clarithromycin treatment of experimental sepsis and acute pyelonephritis caused by multidrug-resistant Pseudomonas aeruginosa.

Clarithromycin was administered intravenously to 55 rabbits to evaluate its effect on experimental sepsis caused by multidrug-resistant Pseudomonas aeruginosa. Acute pyelonephritis was induced after ligation of the right ureter and injection of 10(8) CFU of the test isolate per kg of body weight into the renal pelvis. The animals were divided into six groups: group A, controls; group B, rabbits that received one intravenous dose of 80 mg of clarithromycin per kg concomitantly with bacterial challenge; group C, rabbits that received two doses of clarithromycin, the second one of which was given 2 h after the first one; group D, rabbits that received 15 mg of amikacin per kg; group E, rabbits that received one dose of clarithromycin and amikacin; and group F, rabbits that received two doses of clarithromycin and amikacin. Serum endotoxin levels were estimated by the QCL-1000 Limulus amoebocyte lysate assay, tumor necrosis factor alpha (TNF-alpha) levels were measured by a bioassay, and malondialdehyde (MDA) levels were measured by the thiobarbiturate assay. Viable bacterial counts in various tissue samples were also assessed. The mean survival times of the animals in groups A, B, C, D, E, and F were 4.50, 7.69, 4.07, 4.55, 11.55, and 11.60 days, respectively (P = 0.033 for group D versus group F, P = 0.006 for group D versus group E, P = not significant for group B versus group E, P = 0.042 for group C versus group F). Serum endotoxin levels were similar between groups at all sampling times; TNF-alpha and MDA levels in groups B, C, E, and F decreased significantly over follow-up. The numbers of viable bacterial cells in the infected kidney were similar among the groups; those in the liver, spleen, lungs, and mesenteral lymph nodes were significantly decreased in groups B, E, and F compared to those in groups A and D. It is concluded that a prolongation of survival in animals with experimental sepsis caused by multidrug-resistant P. aeruginosa was achieved after coadministration of clarithromycin and amikacin and that the increased survival was probably attributable to the immunomodulatory properties of clarithromycin.

Monotherapy with mastic does not eradicate Helicobacter pylori infection from mice.

To determine the ability of mastic monotherapy to eradicate Helicobacter pylori infection from mice. The susceptibility of H. pylori SS1 to mastic was assessed by broth dilution determination of the MIC and MBC. Mice were inoculated intragastrically with either a suspension of H. pylori SS1 (n = 70) or brain-heart infusion broth alone (n = 10). Mice were given antimicrobial chemotherapy 4 weeks after infection and were administered the mouse equivalent of either 2 g of mastic twice daily for 7 days or a triple therapy regimen containing the mouse equivalent of 400 mg of metronidazole, 250 mg of clarithromycin and 20 mg of omeprazole twice daily for 7 days. Mice were killed either immediately or 1 month after the completion of treatment, and their stomachs cultured for H. pylori. The mastic MIC and MBC of H. pylori SS1 were 7.80 and 31.25 mg/L, respectively. The triple therapy regimen eradicated infection from 19 of 20 SS1-infected mice. Mastic failed to eradicate infection from any of the 18 SS1-infected mice (P < 0.001) and there was no signifi- cant reduction in gastric bacterial load in mice treated with this regimen. Despite reported beneficial effects in ulcer patients and the good in vitro activity of mastic against H. pylori, this compound is unable to eradicate H. pylori infection from mice.

A case of early adenocarcinoma occured after the treatment high grade MALT lymphoma

An 83-year-old male was diagnosed as high-grade MALT lymphoma of the stomach both endoscopically and pathologically. Eradication of Helicobacter pylori with 40mg of omeprazole, 1,500mg of amoxicillin, 400mg of clarithromycin a day for 10 consecutive days at first and 3 courses of anthracyline-based chemotherapy (CHOP ; 650mg of cyclophosphamide, 40mg of doxorubicine hydrochloride, 1.2mg of vincristine sulfate per a course and 50mg of predoninn a day during a course) were done secondly and 40Gy of ratiation therapy was added to them. 2 months after whole therapies done, endoscopic examination was performed to evaluated the effect of whole therapies. A type of IIa + IIc, an early gastric adenocarcinoma, was newly revealed to be located on the lesser curvature of the middle body of the stomach. Endoscopic therapy with semiconductor lazer was performed due to the patient's request instead of surgery. The effect of H. pylori infection on the pathogenesis of gastric neoplasia has not been cleared yet. This case suggested the some carcinogen from H. pylori might cause both MALT lymphoma and adenocarcinoma of the stomach.

Bactericidal activity of rifampin-amikacin against Mycobacterium ulcerans in mice.

To identify the most active curative treatment of Buruli ulcer, two regimens incorporating the use of rifampin (RIF) were compared with the use of RIF alone in a mouse footpad model of Mycobacterium ulcerans infection. Treatments began after footpad swelling from infection and continued for 12 weeks with five doses weekly of one of the following regimens: (i) 10 mg of RIF/kg alone; (ii) 10 mg of RIF/kg and 100 mg of amikacin (AMK)/kg; and (iii) 10 mg of RIF/kg, 100 mg of clarithromycin (CLR)/kg, and 50 mg of sparfloxacin (SPX)/kg. The activity of each regimen was assessed in terms of the reduction of the average lesion index and acid-fast bacillus (AFB) and CFU counts. All three regimens displayed various degrees of bactericidal activity against M. ulcerans. The ranking of bactericidal activity was found to be as follows: RIF-AMK > RIF-CLR-SPX > RIF. RIF-AMK was able to cure M. ulcerans-infected mice and prevent relapse 26 weeks after completion of treatment. To determine the impact of different rhythms of administration of RIF-AMK on the suppression of M.ulcerans growth, mice were given the RIF-AMK combination for 4 weeks but doses were administered either 5 days a week or twice or once weekly. After completion of treatment, the mice were kept under supervision for 30 additional weeks. M. ulcerans was considered to have grown in the footpad if swelling was visually observed and harvests contained more than 5 x 10(5) AFB per footpad. The proportion of mice in which growth of M. ulcerans occurred, irrespective of drug dosage, was compared with the control mice to determine the proportion of M. ulcerans killed. Each dosage of RIF-AMK was bactericidal for M. ulcerans (P < 0.001), but the effect was significantly stronger in mice treated 5 days per week. The promising results of RIF-AMK treatment in M. ulcerans-infected mice support the clinical trial that is currently in progress under World Health Organization auspices in Ghana.

PPIs meet the liver

This prospective trial evaluated whether CYP2C19 genotype status was related to eradication rates of Helicobacter pylori using triple therapy with a proton pump inhibitor, clarithromycin, and amoxicillin with an attempt to establish a strategy for treating patients whose H. pylori was not eradicated. Study patients consisted of men and women with endoscopically proven gastric ulcers or duodenal ulcers or long-standing gastritis who were positive for H. pylori using a rapid urease test, culture, and histology. The drug regimen for eradication of H. pylori included 20 mg of omeprazole or 30 mg of lansoprazole b.i.d. (randomly selected for proton pump inhibitor use), 200 mg of clarithromycin t.i.d., and 500 mg of amoxicillin t.i.d. for 1 wk. Patients with gastric or duodenal ulcer were treated with a daily dose of 20 mg of omeprazole or 30 mg of lansoprazole for 5–7 wk after triple therapy. Patients whose H. pylori was not eradicated with the initial regimen were retreated with 30 mg of lansoprazole q.i.d. and amoxicillin q.i.d. for 2 wk. Patients received endoscopic evaluation and confirmation of H. pylori status before treatment and 1 month after the end of all treatments. Endoscopic biopsy samples were obtained for rapid urease testing, bacteriological culture for antimicrobial sensitivity, and polymerase chain reaction analysis for genotyping of CYP2C19 status of patients. Patients were categorized into three groups based upon CYP2C19 genotype: homozygous extensive metabolizers, heterozygous extensive metabolizers, and poor metabolizers. There were no significant differences between the groups in demographic or disease state measures. Overall, 226 of 261 patients (86.6%) achieved cure of H. pylori infection. Thirty-three of 261 patients were infected with clarithromycin-resistant strains, whereas culture results revealed no amoxicillin-resistant strains. Differences in the status of CYP2C19 genotype and clarithromycin-resistant H. pylori were significantly associated with success or failure of H. pylori eradication. Eradication rates were 72.7% for homozygous extensive metabolizers, 92.1% for heterozygous metabolizers, and 97.8% for poor metabolizers. Thirty-four of 35 patients who did not achieve H. pylori eradication were classified as extensive metabolizers. Thirty-two of these patients were retreated, achieving H. pylori eradication.

PPIs meet the liver.

Abstract This prospective trial evaluated whether CYP2C19 genotype status was related to eradication rates of Helicobacter pylori using triple therapy with a proton pump inhibitor, clarithromycin, and amoxicillin with an attempt to establish a strategy for treating patients whose H. pylori was not eradicated. Study patients consisted of men and women with endoscopically proven gastric ulcers or duodenal ulcers or long-standing gastritis who were positive for H. pylori using a rapid urease test, culture, and histology. The drug regimen for eradication of H. pylori included 20 mg of omeprazole or 30 mg of lansoprazole b.i.d. (randomly selected for proton pump inhibitor use), 200 mg of clarithromycin t.i.d., and 500 mg of amoxicillin t.i.d. for 1 wk. Patients with gastric or duodenal ulcer were treated with a daily dose of 20 mg of omeprazole or 30 mg of lansoprazole for 5–7 wk after triple therapy. Patients whose H. pylori was not eradicated with the initial regimen were retreated with 30 mg of lansoprazole q.i.d. and amoxicillin q.i.d. for 2 wk. Patients received endoscopic evaluation and confirmation of H. pylori status before treatment and 1 month after the end of all treatments. Endoscopic biopsy samples were obtained for rapid urease testing, bacteriological culture for antimicrobial sensitivity, and polymerase chain reaction analysis for genotyping of CYP2C19 status of patients. Patients were categorized into three groups based upon CYP2C19 genotype: homozygous extensive metabolizers, heterozygous extensive metabolizers, and poor metabolizers. There were no significant differences between the groups in demographic or disease state measures. Overall, 226 of 261 patients (86.6%) achieved cure of H. pylori infection. Thirty-three of 261 patients were infected with clarithromycin-resistant strains, whereas culture results revealed no amoxicillin-resistant strains. Differences in the status of CYP2C19 genotype and clarithromycin-resistant H. pylori were significantly associated with success or failure of H. pylori eradication. Eradication rates were 72.7% for homozygous extensive metabolizers, 92.1% for heterozygous metabolizers, and 97.8% for poor metabolizers. Thirty-four of 35 patients who did not achieve H. pylori eradication were classified as extensive metabolizers. Thirty-two of these patients were retreated, achieving H. pylori eradication.

A case of Ménétrier's disease improved by eradication of Helicobacter pylori infection

We reported a case of Ménétrier's disease associated with hypoproteinemia and enlargement of the gastric folds, which was successfully treated by eradication of Helicobacter pylori (H. p.) infection. A 47-year-old man developed giant fold gastritis associated with H. p. colonization and hypoproteinemia. Histological findings showed focal foveolar hyperplasia in the mucosa of the gastric body. He was treated with 600mg of clarithromycin (200mg three times a day) , 40mg of omeprazole (20mg twice a day) , 1,500mg of amoxicilln (500mg three times a day) for 14 consecutive days. After starting the treatment, the serum albumin and IgG levels increased. The treatment resulted in eradication of H. p. infection and the normalization of giant folds and the mucosal histological findings of the stomach. The serum albumin and IgG levels returned normal within 12 weeks and have remained normal since then. This case suggests both that eradication of H. p. infection is an effective therapy for Ménétrier's disease, and that H. p. infection plays an some etiological role in this disease through the improvement of the disease by eradication of H. p. infection.

Clarithromycin-resistant mycobacterium avium is still susceptible to treatment with clarithromycin and is virulent in mice.

Resistance to clarithromycin in breakthrough Mycobacterium avium complex (MAC) isolates typically occurs 3 to 4 months after the initiation of monotherapy in bacteremic AIDS patients. It has been suggested that continuation of clarithromycin therapy still results in clinical and microbiological improvement. To study this paradox, C57BL/6 beige mice were infected with a clarithromycin-resistant (MIC, > or =128 microg/ml) strain of MAC 101 (CLA-R MAC 101) and treated with 200 mg of clarithromycin per kg of body weight/day alone or in combination with ethambutol (100 mg/kg/day) for 2 weeks. Mice infected with a clarithromycin-susceptible strain of MAC 101 had bacterial loads reduced by 90% in the liver and 91% in the spleen (P<0.05, compared with the control). Clarithromycin treatment of CLA-R MAC 101 resulted in a 65% reduction of bacterial loads in the liver (P = 0.009) and a 71% reduction in the spleen (P = 0.009), compared with the results for the untreated control. CLA-R MAC 101 and MAC 101 (isogenic strains) had comparable growth rates in murine tissue, ruling out a loss of virulence of CLA-R MAC 101. Strains of MAC currently defined as macrolide resistant may still respond to treatment with an agent such as clarithromycin within infected tissues.

Comparison of the efficacy of 400 mg and 800 mg of clarithromycin used with lansoprazole and amoxicillin in eradication regimens for Helicobacter pylori infection in a Japanese population

We conducted a randomized prospective comparative study to determine whether a 1-week lansoprazole-amoxicillin-clarithromycin (LAC) regimen with 800 mg of clarithromycin a day was more effective such a regimen with 400 mg daily in the Japanese population. One hundred and seventy-five Helicobacter pylori-positive patients were randomly assigned to receive one of two different 7-day regimens, one with clarithromycin 400 mg (LAC 400 regimen) and the other with clarithromycin 800 mg (LAC 800 regimen). The cure rates for both regimens were similar, although adverse effects were significantly more frequent in the LAC 800 regimen, suggesting that 400 mg of clarithromycin may be sufficient in our patient population.