Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Clarithromycin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed2000

Helicobacter pylori eradication with lansoprazole, amoxycillin and clarithromycin: testing an ideal regimen in a multicultural south east Asian population and examining factors potentially influencing eradication.

BACKGROUND: From European and North American data, it is recommended in the Asia Pacific consensus statement, that one week therapy with a proton pump inhibitor, amoxycillin and clarithromycin be used for Helicobacter pylori eradication, in areas of high metronidazole resistance. The efficacy of this regimen is unknown in Singapore. AIM: To assess the efficacy, safety and compliance of an H. pylori eradication regimen and examine clinical factors that potentially determine eradication. METHODS: Consecutive outpatients from a multicultural, south east Asian, population with H. pylori infection, with or without peptic ulcer, were treated with lansoprazole 30 mg, amoxycillin 1 gm, clarithromycin 500 mg, twice a day for seven days. Eradication was assessed by either rapid urease, histology or urea breath test. Compliance and side effects were recorded. The eradication rate and effect of ethnicity, age, sex, usage of alcohol, smoking and non-steroidal anti-inflammatory drugs, history of ulcer and endoscopic diagnosis on eradication were examined by univariate and multivariate analysis. RESULTS: Of 113 patients, the eradication rate by intention to treat was 98/113 (87%) (95% confidence interval [CI] 80-93%) and per protocol was 98/106 (92%) (95% CI 87-97%). Using Fisher's exact test, eradication was more successful in Chinese (intention to treat and per protocol respectively p=0.02 and p<0.001) compared to non-Chinese. By logistic regression analysis ethnicity was an independent factor associated with eradication success (p=0.0025). Side effects occurred in five (4.4%), resulting in cessation of treatment. CONCLUSIONS: This one week eradication regimen is safe and effective in south east Asians. Chinese ethnicity may be associated with a higher likelihood of eradication success.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Polymerase chain reaction--restriction fragment length polymorphism analysis of clarithromycin-resistant Helicobacter pylori infection in children using stool sample.

BACKGROUND: To analyze clarithromycin-resistant Helicobacter pylori infection in children, we developed a method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis using stool samples. MATERIALS AND METHODS: Twenty-three children without significant upper abdominal symptoms were included (mean age 7.0 years). Of these, 18 and five were diagnosed as H. pylori-positive and -negative, respectively, by the H. pylori stool antigen test (HpSA). The DNA from the stool samples was purified using the QIAamp DNA Stool Minikit (QIAGEN). The PCR was performed on the purified DNA using oligonucleotide primers designed to amplify the 23S rRNA gene of H. pylori. The PCR products were reacted with restriction enzymes MboII, BceAI, and BsaI to detect mutations A2142G, A2142C, and A2143G, respectively. RESULTS: Sixteen of the 18 HpSA-positive samples were PCR-positive, and all five HpSA-negative samples were PCR-negative. Thus, the PCR had 89% sensitivity and 100% specificity, with 91% accuracy in reference to HpSA. Of the 16 PCR-positive samples, one and four were digested with MboII and BsaI, respectively, indicating 31% prevalence of CAM-resistance. CONCLUSIONS: We conclude that the PCR-RFLP using stool samples is a rapid and reliable method to noninvasively detect clarithromycin-resistant H. pylori infection in children. It may be useful before choosing regimens of H. pylori eradication.

Adolescent↗
PubMed2005

Long-term follow-up after eradication of Helicobacter pylori with omeprazole, clarithromycin, and tinidazole (OCT regimen) in a Japanese population.

BACKGROUND: The long-term benefit of Helicobacter pylori eradication treatment that includes metronidazole on peptic ulcer disease in Japan is unclear. We investigated the rate of H. pylori re-infection and ulcer relapse after H. pylori eradication. MATERIALS AND METHODS: A total of 266 patients with endoscopically confirmed peptic ulcer disease and H. pylori infection were treated with triple therapy of omeprazole 40 mg (20 mg b.i.d.), clarithromycin 800 mg (400 mg b.i.d.), and tinidazole 1000 mg (500 mg b.i.d.) for 7 days. Endoscopy with gastric biopsy was performed before and 1 month, 6 months, 1.5 years, and 3.5 years after therapy. H. pylori status was determined by H. pylori culture, rapid urease test, and histopathology. 13C-urea breath test was done at 6 months after eradication therapy. Treatment was deemed successful when all tests were negative at 6 months after therapy by endoscopic biopsy. RESULTS: Successful H. pylori eradication was achieved in 262/266 (98.5%) patients with peptic ulcer. Total relapse of peptic ulcer occurred in 8/262 (3%) patients after eradication, with 3/262 (1.1%) occurring within 1.5 years after treatment and 5/262 (1.9%) within 3.5 years. All relapsed patients were found to be H. pylori-positive at the time of relapse. Of the 262 patients who experienced eradication, 20 (7.6%) were subsequently re-infected, six (2.3%) within 1.5 years and 14 (5.3%) within 3.5 years. CONCLUSION: Triple therapy with omeprazole, clarithromycin, and tinidazole (OCT) is useful for H. pylori eradication in Japan, but there is an appreciable re-infection rate in this population.

Adult↗
PubMed1997

A surgical wound infection due to Mycobacterium chelonae successfully treated with clarithromycin.

BACKGROUND: Mycobacterium chelonae is an uncommon but recognized cause of chronic localized cutaneous infection at a site of penetrating trauma or a surgical wound. OBJECTIVE: The problem faced by physicians encountering an infection by M. chelonae is often response to therapy, which may be highly variable. METHODS: We describe an immunocompetent patient who developed a localized infection due to M. chelonae following surgery for a basal cell carcinoma of the lower leg. RESULTS: The infection responded to treatment with clarithromycin. CONCLUSION: The clinical efficacy of clarithromycin and the salient features of M. chelonae infection and its treatment are discussed.

Aged↗
PubMed2002

Comparison of azithromycin and clarithromycin in triple therapy regimens for the eradication of Helicobacter pylori.

OBJECTIVE: We sought to compare an azithromycin-based regimen with an already established clarithromycin-based regimen in the eradication of Helicobacter pylori infection. METHODS: A prospective, randomized, blinded comparative analysis was performed on 56 patients with upper GI symptoms who presented to the Gastroenterology Department at the Naval Medical Center Portsmouth. All patients had documented H. pylori infection on endoscopy via rapid urease test and histopathology. Patients were randomized to a treatment arm, which consisted of bismuth, clarithromycin, amoxicillin, and lansoprazole (B-LAC) or one consisting of bismuth, azithromycin, amoxicillin, and lansoprazole (B-LAA). To assess eradication, patients then received repeat endoscopy at 8 wk from entrance into the study. Rapid urease test and histopathology were again used to evaluate infection. Patients recorded all side effects. Comparison between the two groups was made using the chi2 method. RESULTS: Of the 56 patients included in the study, 27 went on to receive B-LAC, whereas 29 received B-LAA. The per protocol eradication rate was 84.6% with B-LAC and 55.5% with B-LAA (p = 0.021). Under intention to treat analysis, the eradication rates for B-LAC and B-LAA were 81% and 52%, respectively (p = 0.019). There was a significant difference between the two groups in number of subjects using nonsteroidal anti-inflammatory drugs (NSAIDs) (p = 0.013) and a trend toward a difference in histamine-2 (H2) blocker use (p = 0.066). Taking these two variables into account, a logistical regression was performed and continued to show a significant superiority in the B-LAC regimen (p = 0.03). CONCLUSIONS: The results of our study suggest that B-LAC is superior to B-LAA in the eradication of Helicobacter pylori. Our results also suggest that B-LAA is not a suitable regimen in the treatment of H. pylori because of its substandard eradication rate.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

Clarithromycin pharmacokinetics after oral administration with or without fasting in crossbred beagles.

Clarithromycin was administered to eight dogs intravenously and orally. A suspension or a tablet was given to animals both immediately after feeding and on an empty stomach. Neither the formulation nor the time of administration in relation to feeding significantly influenced the pharmacokinetic parameters. The lowest mean (+/-SD) maximum plasma concentration (Cmax) of 3.0 +/- 0.6 micrograms/ml, the lowest bioavailability (F) of approximately 69 per cent and the shortest time above the proposed breakpoint of susceptibility (L) of 2.9 +/- 1.3 hours were observed with the suspension after feeding. The highest Cmax of 3.6 +/- 0.8 micrograms/ml, the highest F of 83 per cent and the longest L of 4.5 +/- 2.0 hours were observed with the suspension in the fasted group. The mean time at which Cmax occurred (tmax) was between one and two hours after administration. In conclusion, clarithromycin is potentially suitable for therapeutic use in dogs, pending species-specific studies of safety and therapeutic efficacy.

Administration, Oral↗
PubMed1989

Comparative antimycobacterial activities of difloxacin, temafloxacin, enoxacin, pefloxacin, reference fluoroquinolones, and a new macrolide, clarithromycin.

The activities of fluoroquinolones and a new macrolide against 30 clinical isolates of Mycobacterium tuberculosis were determined in vitro by agar diffusion. In order of relative potencies against M. tuberculosis, temafloxacin (MIC for 90% of isolates [MIC90], 2.3 micrograms/ml) was at least as active as the reference quinolones ofloxacin (MIC90, 2.4 micrograms/ml) and ciprofloxacin (MIC90, 4.3 micrograms/ml). Less active were difloxacin (MIC90, 4.7 micrograms/ml), pefloxacin (MIC90, 6.7 micrograms/ml), and enoxacin (MIC90, 8.3 micrograms/ml). The macrolide clarithromycin was more potent than erythromycin but less potent than the fluoroquinolones. Our results suggest that the newer fluoroquinolones and clarithromycin should be included with ciprofloxacin and ofloxacin in pharmacokinetic studies that may lead to trials in human subjects with mycobacterial infections.

Anti-Bacterial Agents↗
PubMed1991

Effect of pH on the in vitro potency of clarithromycin against Mycobacterium avium complex.

Employing 7H11 agar medium at pH 6.6, the MICs of clarithromycin for 50% (MIC50) and 90% (MIC90) of 19 strains of Mycobacterium avium complex were 8 and 16 micrograms/ml, respectively. However, the MICs were 2 to 3 log2 dilutions lower in the 7H11 medium adjusted to pH 7.4, and the MICs on 10% OADC (oleic acid-albumin-dextrose-catalase)-enriched Mueller-Hinton agar at pH 7.3 were also 2 log2 dilutions lower than those measured on 7H11 agar at pH 6.6. Therefore, clarithromycin is more active at a physiologic than at an acidic pH.

Clarithromycin↗
PubMed1992

Pharmacokinetics of a clarithromycin suspension in infants and children.

The single- and multiple-dose pharmacokinetics of clarithromycin and its 14-(R)-hydroxylated metabolite in infants and children were studied after oral administration under fasting and nonfasting conditions. Drug absorption appeared to be rapid following a brief delay in its onset; the mean peak concentrations in plasma (Cmax) for clarithromycin were reached within about 3 h under both conditions. The mean Cmax for the parent drug were 3.59 and 4.58 micrograms/ml in single-dose fasting and nonfasting patients, and the respective Cmax for the metabolite were 1.19 and 1.26 micrograms/ml. Data indicate good absorption and no significant effects by food. There was no unusual accumulation in the area under the concentration-time curve and Cmax in the multiple-dose group.

Administration, Oral↗
PubMed1992

Effect of pH on radiometric MICs of clarithromycin against 18 species of mycobacteria.

The antimycobacterial spectrum of clarithromycin, a new macrolide drug, was screened against 26 strains belonging to 18 species of mycobacteria by determining radiometric MICs by Bactec methodology at three different pHs, i.e., pH 6.0, 6.8, and 7.4. The MICs obtained at pH 7.4 were 1 to 2 or more dilutions lower in some of the species than those obtained at pH 6.8, whereas they were significantly higher at pH 6.0. The numbers of species for which MICs were below the Cmax levels of clarithromycin (i.e., 4 micrograms/ml) at different pHs were 8 of 18 species at pH 6.0, 13 of 18 species at pH 6.8, and 14 of 18 species at pH 7.4. The drug possessed promising activity against such potential pathogens as M. avium, M. scrofulaceum, M. szulgai, M. malmoense, M. xenopi, M. marinum, and M. kansasii and rare pathogens like M. chelonei.

Clarithromycin↗
PubMed1992

Absolute bioavailability of clarithromycin after oral administration in humans.

The absolute bioavailability of clarithromycin, a new macrolide antimicrobial agent, was assessed in a three-way, randomized, single-dose, crossover study conducted with 22 healthy volunteers, 19 of whom provided analyzable study data. The bioavailability parameters of two 250-mg oral tablet formulations were calculated with reference to an identical dose administered by intravenous infusion of the lactobionate salt. After adjustment for formulation potency, the mean absolute bioavailabilities of the two oral formulations were 52 and 55%, on the basis of the appearance of parent compound in the systemic circulation. Metabolite peak concentration and area under the plasma concentration-time curve data after oral dosing were generally greater than those after intravenous infusion, suggesting that marked first-pass metabolism of clarithromycin occurs after oral administration. Pharmacokinetic analysis of the parent drug and the active 14-hydroxy metabolite data suggests complete (or nearly complete) absorption of the drug after oral administration.

Administration, Oral↗
PubMed1992

Activities of clarithromycin against eight slowly growing species of nontuberculous mycobacteria, determined by using a broth microdilution MIC system.

MICs of clarithromycin against 324 clinical isolates belonging to eight species of slowly growing nontuberculous mycobacteria were determined by using a broth microdilution system. Isolates were inoculated into twofold drug dilutions in Middlebrook 7H9 broth (pH corrected to 7.4) and then incubated at 30 degrees C for 7 days for Mycobacterium marinum and for 14 days for all other species. The MIC for 90% of the strains (MIC90) was less than or equal to 0.5 micrograms/ml for isolates of Mycobacterium gordonae (6 strains), Mycobacterium scrofulaceum (5 strains), Mycobacterium szulgai (6 strains), and Mycobacterium kansasii (35 strains). MICs for M. marinum (25 strains) and Mycobacterium avium complex (237 strains) were higher, but 100% and 89% of the strains, respectively, were susceptible to less than or equal to 4 micrograms/ml. In contrast, MICs for five of six M. simiae strains were greater than 8 micrograms/ml, and the range of MICs for Mycobacterium nonchromogenicum varied from less than or equal to 0.125 to 8 micrograms/ml. For the 237 isolates of M. avium complex, the MIC50 was 2 micrograms/ml and the MIC90 was 8 micrograms/ml. MICs for most isolates (77%) were in the 1- to 4-micrograms/ml range. For the 80 isolates in this group known to be from AIDS patients, the MIC50 was 4 micrograms/ml and the MIC90 was 8 micrograms/ml. These MIC studies combined with preliminary clinical trials suggest that clarithromycin may be useful for drug therapy of most species of the slowly growing nontuberculous mycobacteria except M. simiae.

Clarithromycin↗
PubMed1992

In vitro susceptibility of Mycobacterium kansasii to clarithromycin.

The MICs of the macrolide clarithromycin for 31 clinical isolates of Mycobacterium kansasii were determined by three different methods. The methods employed were the proportion resistance method on 7H10 agar, the radiometric (BACTEC) method, and the T100 method of datum analysis. All methods gave similar results. The MICs were in a narrow range from 0.16 to 0.50 microgram/ml, with the MICs for 90% of isolates tested of 0.50 microgram/ml for the agar dilution and radiometric methods and 0.37 microgram/ml for the T100 method. The MBCs were determined for nine representative isolates by the radiometric broth method. The MBCs were equal to the MICs for four isolates, and the MBCs were twofold higher than the MICs for five isolates. Killing of 99.9% of the bacterial population was achieved at a clarithromycin concentration of 2.0 micrograms/ml for all nine isolates tested.

Clarithromycin↗
PubMed1993

Erythromycin, clarithromycin, and azithromycin: use of frequency distribution curves, scattergrams, and regression analyses to compare in vitro activities and describe cross-resistance.

MICs of erythromycin, clarithromycin, and azithromycin for 852 recent clinical isolates were determined by broth microdilution methods. Frequency distribution curves, scattergrams, and regression analyses were used to compare in vitro activities and describe cross-resistance. Clarithromycin was the most active drug against Bacteroides spp. but the least active against Haemophilus influenzae. Azithromycin was most active against H. influenzae, Moraxella catarrhalis, Pasteurella multocida, and Fusobacterium spp. but the least active against Streptococcus spp. and Enterococcus spp. All three drugs had equivalent activities against Staphylococcus spp. and gram-positive anaerobes. None of the three drugs was particularly active against members of the family Enterobacteriaceae or nonfermentative gram-negative bacilli, although concentrations of 4 micrograms of azithromycin per ml inhibited some strains of the family Enterobacteriaceae (particularly Escherichia coli and Citrobacter diversus) and Acinetobacter baumannii. Although relative drug activities varied by organism, organisms relatively susceptible to one were relatively susceptible to all and organisms relatively resistant to one were relatively resistant to all; an exception was fusobacteria, which were usually susceptible only to azithromycin. Cross-susceptibility and cross-resistance were, therefore, the rule (except for Fusobacterium spp.), although the percentage of susceptible organisms could be varied considerably on the basis of the selection of breakpoints.

Azithromycin↗
PubMed1993

Comparative susceptibilities of 173 aerobic and anaerobic bite wound isolates to sparfloxacin, temafloxacin, clarithromycin, and older agents.

The in vitro activities of sparfloxacin, temafloxacin, ciprofloxacin, ofloxacin, clarithromycin, erythromycin, tetracycline, cephalothin, penicillin G, and amoxicillin-clavulanic acid against 173 recent clinical bite wound isolates were determined by agar dilution. Sparfloxacin was active against all strains (MIC for 90% of strains tested, < or = 1 micrograms/ml) except for most fusobacteria and one-third of the Prevotella spp. The other fluoroquinolones had similar activities but higher MICs, especially for streptococci. Clarithromycin was more active against many isolates including Pasteurella multocida than erythromycin, with MICs of < or = 2 micrograms/ml (versus 4 micrograms/ml for erythromycin).

Animals↗
PubMed1993

Inhibition of intracellular growth of Mycobacterium avium by one pulsed exposure of infected macrophages to clarithromycin.

A single 2-h pulsed exposure of either human monocyte-derived macrophages or J774 cells infected with Mycobacterium avium to clarithromycin at 3.0 micrograms/ml completely inhibited the intracellular bacterial growth during the first four days of observation, and then only a slight increase in the number of CFU per milliliter took place between the fourth and seventh days. These data suggest that in vivo the intracellular bacteria can be effectively inhibited after a short period when the concentration of the drug in blood reaches its maximum. On the basis of these data, the assumptions that the elimination of bacteremia observed in clarithromycin clinical trials is a result of the activity of the drug not only against bacteria in blood but in macrophages as well and that the peak concentration attainable in blood is essential for these effects can be made.

Cells, Cultured↗
PubMed1994

Effect of CO2 on susceptibilities of anaerobes to erythromycin, azithromycin, clarithromycin, and roxithromycin.

The Oxyrase agar dilution method (Oxyrase, Inc., Mansfield, Ohio), which provides an anaerobic environment without added CO2, was compared with the reference agar dilution method recommended by the National Committee for Clinical Laboratory Standards (anaerobic chamber with 10% CO2) to test the susceptibilities of 302 gram-negative and gram-positive anaerobes to erythromycin, azithromycin, clarithromycin, and roxithromycin. For erythromycin, the overall MIC for 50% of isolates tested (MIC50) was 0.5 micrograms/ml and the MIC90 was 8.0 micrograms/ml by the Oxyrase method, whereas they were 4.0 and 64.0 micrograms/ml, respectively, under standard anaerobic conditions with CO2. At a breakpoint of 4.0 micrograms/ml, 88% of strains were susceptible to erythromycin by the Oxyrase method, whereas 63% were susceptible in the chamber. The corresponding MIC50s and MIC90s of azithromycin, clarithromycin, and roxithromycin by the Oxyrase method were 0.5 and 8.0, 0.25 and 4.0, and 0.5 and 16.0 micrograms/ml, respectively, whereas in the chamber they were 4.0 and > 64.0, 2.0 and 64.0, and 2.0 and 64.0 micrograms/ml, respectively. At a breakpoint of 8.0 micrograms/ml for these three drugs, 89, 92, and 85% of the isolates, respectively, were susceptible by the Oxyrase method, whereas 67%, 72, and 68% of the isolates, respectively, were susceptible in the chamber. Most strains resistant to all four compounds by both methods were Bacteroides distasonis, Fusobacterium mortiferum, Fusobacterium varium and non-Clostridium perfringens Clostridium species. Results of the study may lead to a reappraisal of the role played by macrolides and azalides in the treatment of anaerobic infections.

Azithromycin↗
PubMed1994

Activity of KRM 1648 alone or in combination with ethambutol or clarithromycin against Mycobacterium avium in beige mouse model of disseminated infection.

Rifamycins are active against slowly growing mycobacteria, such as Mycobacterium tuberculosis and Mycobacterium kansasii, but the majority of rifamycins thus far investigated both in vitro and in vivo are inactive or have only modest activity against the Mycobacterium avium complex (MAC). We investigated the activity of three doses of the semisynthetic benzoxazinorifamycin KRM 1648, alone or in combination with ethambutol or clarithromycin, in beige mice challenged with the MAC strain 101. Our results show the following. (i) KRM 1648 was significantly effective against MAC infection as determined by the reduction of the number of bacteria in the blood, liver, and spleen when administered at doses of 20 and 40 mg/kg of body weight per day but not at 10 mg/kg/day, compared with untreated controls. (ii) KRM 1648 (40 mg/kg/day) administered in combination with ethambutol (100 mg/kg/day) resulted in significant reduction in bacteremia compared with values for untreated controls (P 0.001), KRM 1648 alone (P = 0.019), and ethambutol alone (P = 0.003). Furthermore, the combination of KRM 1648 and ethambutol was associated with a significant decrease of the number of bacteria in the spleen and the liver compared with values for both untreated controls and each drug alone (P < 0.001 for all comparisons). (iii) KRM 1648 (40 mg/kg/day) administered in combination with clarithromycin (200 mg/kg/day) resulted in a significant decrease of the number of bacteria in the blood and the spleen compared with the number for untreated controls (P < 0.001 for all comparisons). In our experience, using MAC 101 as the challenging organism, KRM 1648 is the first the number of bacteria in the blood and spleen compared with the number for untreated controls (P >0.001 for all comparions). In our experience, using MAC 101 as the challenging organism, KRM 1648 is the first rifamycin with significant activity in vivo against MAC infection in beige mice.

Animals↗