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PubMed1998

Leukocytoclastic vasculitis associated with clarithromycin.

OBJECTIVE: To report a possible case of leukocytoclastic vasculitis associated with clarithromycin therapy. CASE SUMMARY: An 83-year-old white woman was prescribed clarithromycin for pneumonia. Six days after her initial presentation, she developed lesions on her palms. Clarithromycin was discontinued at that time. The following day she developed purpuric eccymotic nonblanching lesions that primarily appeared on the lower extremities, buttocks, and abdomen. Colonoscopy revealed generalized erythema and edema of the bowel mucosa. Gastroscopy revealed duodenitis and gastritis, but no bleeding or ulceration. Skin biopsy of the lesions was compatible with leukocytoclastic vasculitis. Renal function was not affected, although hematuria was noted. All symptoms resolved after drug withdrawal and a short course of corticosteroids. DATA SOURCES: Searches were performed on MEDLINE, Embase, International Pharmaceutical Abstracts, and major adverse drug reaction databases to identify reports and articles discussing clarithromycin- and macrolide-induced leukocytoclastic vasculitis. DISCUSSION: Leukocytoclastic vasculitis is one category of drug hypersensitivity reactions characterized by distinctive patterns of perivascular inflammation. The case described here is consistent with the diagnosis of leukocytoclastic vasculitis, and is similar to the other single published case report associated with clarithromycin. CONCLUSIONS: Leukocytoclastic vasculitis induced by clarithromycin is a rare but serious potential adverse effect.

Aged↗
PubMed2002

Mycoplasma pneumoniae and Chlamydia pneumoniae in asthma: effect of clarithromycin.

STUDY OBJECTIVES: To determine the effect of clarithromycin therapy in patients with asthma. DESIGN: Randomized, double blind, placebo-controlled trial. SETTING: A tertiary referral center. PATIENTS OR PARTICIPANTS: Fifty-five subjects with chronic, stable asthma recruited from the general Denver, CO, community. INTERVENTIONS: Patients underwent airway evaluation for Mycoplasma pneumoniae and Chlamydia pneumoniae by polymerase chain reaction (PCR) and culture, followed by treatment with clarithromycin, 500 bid, or placebo for 6 weeks. MEASUREMENTS AND RESULTS: Outcome variables were lung function, sinusitis as measured by CT, and the inflammatory mediators tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, IL-4, IL-5, and IL-12 messenger RNA (mRNA) measured via in situ hybridization, in airway biopsies, and BAL. Mycoplasma or chlamydia were detected by PCR in 31 of 55 asthmatics. Treatment resulted in a significant improvement in the FEV(1), but only in the PCR-positive subjects (2.50 +/- 0.16 to 2.69 +/- 0.19 L, mean +/- SEM; p = 0.05). This was not appreciated in the PCR-negative subjects (2.59 +/- 0.24 to 2.54 +/- 0.18 L, p = 0.85) or the PCR-positive or PCR-negative subjects who received placebo. Sinus CTs revealed no change in sinusitis with clarithromycin treatment. In situ hybridization revealed no significant difference in baseline airway tissue or BAL-mediator expression between the PCR-positive and PCR-negative subjects. However, the PCR-positive subjects who received clarithromycin demonstrated a reduction in TNF-alpha (p = 0.006), IL-5 (p = 0.007), and IL-12 (p = 0.004) mRNA in BAL and TNF-alpha mRNA in airway tissue (p = 0.0009). The PCR-negative subjects who received clarithromycin only demonstrated a reduction in TNF-alpha (p = 0.01) and IL-12 (p = 0.002) mRNA in BAL and TNF-alpha mRNA in airway tissue (p = 0.004). There were no significant differences in cytokine expression in those subjects who received placebo. CONCLUSIONS: These observations support the hypothesis that clarithromycin therapy improves lung function, but only in those subjects with positive PCR findings for M pneumoniae or C pneumoniae.

Adult↗
PubMed2005

Single-dose azithromycin microspheres vs clarithromycin extended release for the treatment of mild-to-moderate community-acquired pneumonia in adults.

BACKGROUND: Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality worldwide. The inability or failure of many subjects to adhere to standard antibiotic regimens, which may last up to 10 days, results in suboptimal antibiotic treatment. Treatment with a single-dose antibiotic regimen may improve compliance with prescribed therapy. A novel microsphere formulation of azithromycin provides a single-dose regimen while maintaining tolerability. STUDY OBJECTIVE: To compare the efficacy and safety of a single 2.0-g dose of azithromycin microspheres to that of an extended-release formulation of clarithromycin (1.0 g/d for 7 days) for the treatment of adults with mild-to-moderate CAP. DESIGN: A phase III, multinational, multicenter, randomized, double-blind, double-dummy study, comparing single-dose azithromycin microspheres to extended-release clarithromycin, both administered orally. METHODS: Subjects with mild-to-moderate CAP (Fine class I and II) were included. The primary end point was clinical response at the test-of-cure (TOC) visit (days 14 to 21) in the clinical per protocol (CPP) population. The bacteriologic response at the TOC visit was assessed in subjects with a baseline pathogen. RESULTS: A total of 501 subjects were randomized, and 499 were treated. Clinical cure rates at the TOC visit in the CPP population were 92.6% (187 of 202 subjects) for azithromycin microspheres and 94.7% (198 of 209 subjects) for extended-release clarithromycin. Overall pathogen eradication rates were 91.8% (123 of 134 subjects) for azithromycin microspheres and 90.5% (153 of 169 subjects) for extended-release clarithromycin. Both agents were well tolerated. The incidence of treatment-related adverse events was 26.3% with azithromycin microspheres and 24.6% with extended-release clarithromycin. Most adverse events were mild to moderate in severity. CONCLUSION: A single 2.0-g dose of azithromycin microspheres was as effective and well tolerated as a 7-day course of extended-release clarithromycin in the treatment of adults with mild-to-moderate CAP.

Adult↗
PubMed2000

Clarithromycin bioequivalence study of two oral formulations in healthy human volunteers.

OBJECTIVE: To assess the bioequivalence of two tablet formulations of clarithromycin (Clamicin 500 mg from Medley Indlistria Farmaceutica, Brazil, as the test formulation, and Biaxin 500 mg from Abbott Industries, USA, as the reference formulation). METHODS: A single 500 mg oral dose of each formulation was administrated in 24 healthy volunteers of both sexes (12 males and 12 females). The study was conducted open, randomized, two-period crossover design with a 7-day interval between doses. The plasma concentrations of clarithromycin were quantified by reversed phase liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using multiple reaction monitoring (MRM) method. 14-hydroxyclarithromycin concentration was estimated semiquantitatively as equivalent of clarithromycin/ml. The precision of the method was evaluated using calibration curves and plasma quality control samples. The pharmacokinetic parameters calculated for both compounds included: AUC(0 - 48h), AUC(0 - infinity), Cmax, Cmax/AUC(0 - 48h), Tmax, T1/2 and Ke. RESULTS: Standard curves of clarithromycin in plasma were linear in the range of 0.05 microg x ml(-1) to 10 microg x ml(-1) (r > 0.999). The limit of quantification was 5 ng/ml. Within- and between-run plasma quality control CV were 5.8% and 15.7%, respectively. Inaccuracy within- and between-runs were 14% and 17%, respectively. 90% CI for clarithromycin geometric mean AUC(0 - 48h), AUC(0 - infinity) and Cmax ratios (test/reference) were: 8.7% - 103.1%, 89.4% - 103.7% and 85.4% - 99.6%, respectively, and for hydroxyclarithomycin were 80.3% - 108.6%, 80.1% - 110.1% and 85.4% - 112.6%, respectively. CONCLUSION: The method described for the quantification of charithomycin and its main metabolite is accurate and sensitive. Clamicin was considered bio-equivalent to Biaxin based on the rate and extent of absorption. Since these were no significant differences in the bioequivalence determined using the pharmacokinetic parameters of either clarithromycin or 14-hydroxyclarithromycin, we suggest that future bioequivalence trials of this drug may be performed by quantifying clarithromycin only.

Adult↗
PubMed2006

Studies on drug interactions between esomeprazole, amoxicillin and clarithromycin in healthy subjects.

OBJECTIVE: A combination of esomeprazole, amoxicillin and clarithromycin may be used for Helicobacter pylori eradication. We explored the potential for interactions between these drugs. METHODS: In 2 randomized, 4-way crossover studies, healthy CYP2C19 extensive metabolizers (EMs) received esomeprazole 40 mg once daily (n = 20) or 20 mg twice daily (b.i.d.) (n = 20), clarithromycin 500 mg b.i.d., amoxicillin 1 g b.i.d. or the combination of the 3 drugs for 7 days. In a third randomized, 2-way, crossover study, 6 healthy CYP2C 19 poor metabolizers (PMs) received esomeprazole 40 mg once daily with and without clarithromycin 500 mg b.i.d. for 1 week. RESULTS: Triple therapy with esomeprazole 40 mg increased the area under the plasma concentration-time curve during the dosing interval (AUCtau) from 13.31 micromol x h/l (11.12-15.93) for esomeprazole alone to 22.69 micromol x h/l (18.94-27.17) for triple treatment. Respective AUCtau values with esomeprazole 20 mg b.i.d. were 4.97 micromol.h/l (3.97-6.21) and 11.29 micromol x h/l (9.03-14.12). Clarithromycin and amoxicillin plasma levels were largely unchanged by combination therapy. In PMs, the esomeprazole AUC also approximately doubled when administered in combination with clarithromycin. All treatments were well tolerated. CONCLUSION: Clarithromycin decreases the metabolism rate of esomeprazole, leading to approximately doubled AUC values, both in EMs and PMs.

Adult↗
PubMed2000

Effect of clarithromycin on the pharmacokinetics of carbamazepine in rhesus monkeys.

Clarithromycin, an advanced-generation macrolide antimicrobial, is less prone to drug interactions as compared to erythromycin. Based on two case reports in which increased carbamazepine (CBZ) plasma concentrations were observed in patients receiving clarithromycin, a crossover multiple dose study was designed to find out the pharmacokinetic interaction between CBZ and clarithromycin in rhesus monkeys. CBZ (46 mg/kg/d) was administered to the monkeys alone and along with clarithromycin (20 mg/kg/d). Blood samples were collected from 0-24 h. Plasma concentrations of CBZ were measured by HPLC technique. Pharmacokinetic data revealed an increase in plasma concentrations, AUC(0-24) and t1/2e of CBZ when coadministered with clarithromycin, but the increase was not statistically significant. These findings suggest careful administration and plasma monitoring of CBZ concentrations when coadministered with clarithromycin.

Animals↗
PubMed2001

In vivo effect of clarithromycin on multiple cytochrome P450s.

The in vivo effects of oral clarithromycin administration on the in vivo activity of cytochrome P450 1A2, 2C9, and 2D6 were determined. The cytochrome P450 probes caffeine (CYP1A2), tolbutamide (CYP2C9), and dextromethorphan (CYP2D6) were administered as an oral cocktail prior to and 7 days after oral clarithromycin (500 mg twice daily) administration to 12 healthy male subjects. Blood and urine samples were collected and assayed for each of the compounds and their metabolites using high-performance liquid chromatography. The CYP1A2 indices, oral caffeine clearance (6.2 +/- 3.3 l/h before and 5.7 +/- 4.2 l/h after, p > 0.05) and the 6-h paraxanthine to caffeine serum concentration ratio (0.49 +/- 0.3 before and 0.44 +/- 0.3 after, p > 0.05), were unchanged following clarithromycin dosing. Neither the tolbutamide oral clearance (0.77 +/- 0.28 l/h before and 0.72 +/-0.24 l/h after, p > 0.05) nor the tolbutamide urinary metabolic ratio (779 +/- 294 before and 681 +/- 416 after, p > 0.05) indices of CYP2C9 were altered by clarithromycin administration. In the case of CYP2D6, the dextromethorphan to dextrorphan urinary ratio was not significantly different before (0.021 +/- 0.04) and after (0.024 +/- 0.06) clarithromycin dosing. In conclusion, clarithromycin does not appear to alter the in vivo catalytic activity of CYP1A2, CYP2C9, and CYP2D6 in healthy individuals as assessed by caffeine, tolbutamide, and dextromethorphan, respectively.

Adult↗
PubMed2004

[Prevalence of Helicobacter pylori resistant to clarithromycin, amoxicillin and metronidazole in children].

OBJECTIVE: To investigate the prevalence of Helicobacter pylori (Hp) resistant to clarithromycin, amoxicillin and metronidazole in children. METHODS: A total of 44 Hp clinical isolates were cultured from children patients with Hp gastritis and peptic ulcer who underwent gastroscopy during the period from October 2002 to November 2003 in Children's Hospital affiliated to Medical College of Zhejiang University. Nineteen of the patients were girls and 25 boys. The mean age was 8.66 +/- 2.66 years (3 approximately 14 years). The susceptibilities of the 44 Hp strains to clarithromycin, amoxicillin and metronidazole were tested by agar dilution test to determine minimum inhibitory concentration (MIC)(50), MIC(90) and resistance rates were also calculated. RESULTS: Among the 44 Hp strains isolated from children, 8, 4, and 14 strains were resistant to clarithromycin, amoxicillin and metronidazole and the resistant rate was 18.2% (8/44), 9.1% (4/44) and 31.8% (14/44), with MICs for all strains ranging from < 0.125 microg/ml to 64 microg/ml, < 0.125 microg/ml to 64 microg/ml and < 0.125 microg/ml to 128 microg/ml, respectively. MIC(50) and MIC(90) of clarithromycin, amoxicillin and metronidazole were < 0.125 microg/ml, 8 microg/ml; < 0.125 microg/ml, 0.5 microg/ml; 0.5 microg/ml, 128 microg/ml, respectively. The prevalence of Hp resistant to clarithromycin was higher in children than that in adults, while to metronidazole was lower than that in adults with high MICs (32 - 128 microg/ml) and MIC(90) (128 microg/ml) of metronidazole for resistant isolates. Three multidrug resistant strains (6.8%) were simultaneously resistant to these three antibiotics. CONCLUSIONS: The prevalence of Helicobacter pylori resistant to metronidazole was high in children, and the rate of resistance to clarithromycin was higher than that isolated from adults. Amoxicillin-resistant strains were now found, and multidrug resistant strains which resistant to the three antibiotics also emerged.

Adolescent↗
PubMed1995

Clarithromycin versus cefaclor in lower respiratory tract infections. The Canadian Bronchitis Study Group.

A randomized study was done to compare the efficacy of clarithromycin 250 mg or 500 mg b.i.d., vs. cefaclor 250 mg or 500 mg t.i.d. for 7-14 d in 197 evaluable patients with lower respiratory tract infection. Ninety-five patients received clarithromycin, 88 with acute bronchitis or exacerbation of chronic bronchitis, and 7 with pneumonia. One hundred and two patients received cefaclor, 86 with bronchitis and 16 with pneumonia. Ten patients (10.5%) in the clarithromycin group did not complete the trial, 5 (5.3%) because of adverse event, and 3 (3.2%) because of clinical failure. Similarly, 11 patients (10.8%) did not complete cefaclor, 2 (2%) because of adverse event, and 7 (6.9%) because of clinical failure. Clinical cure or improvement was observed in 90 (94.7%) of patients on clarithromycin vs. 92 (90.2%) on cefaclor, p = 0.66. Bacteriologic cure was seen in 26/36 patients (72.2%) on clarithromycin vs. 28/40 patients (70%) on cefaclor, p = 0.28. Clarithromycin is just as effective as cefaclor for lower respiratory tract infections and is well tolerated.

Bronchitis↗
PubMedDate not supplied

Clarithromycin-carbamazepine interaction in a clinical setting.

BACKGROUND: Clarithromycin was used to treat lower respiratory tract infection in several developmentally disabled men who were also taking carbamazepine for seizure disorder. METHODS: We studied retrospectively the use of clarithromycin in 5 patients taking carbamazepine. Because a drug interaction was suspected, the carbamazepine dosage was decreased during treatment, and serum levels were measured 3 to 5 days after change in therapy. In this study, we compared these findings with the base-line pretreatment and posttreatment dosage and serum levels of carbamazepine. RESULTS: Despite decreasing the dosage of carbamazepine by 30 to 40 percent, the serum levels of this drug increased in all of our patients while taking clarithromycin, including 3 patients who developed toxic serum levels of carbamazepine. CONCLUSION: There is a serious drug interaction between carbamazepine and clarithromycin. If possible, we believe that using clarithromycin should be avoided in patients taking carbamazepine. If clinical judgment suggests clarithromycin should be used, however, we suggest decreasing the dosage of carbamazepine by 30 to 50 percent, monitoring the serum drug levels closely, and warning the patient about the signs and symptoms of carbamazepine toxicity.

Adult↗
PubMedDate not supplied

In vitro activity of clarithromycin, cefprozil, and other common oral antimicrobial agents against gram-positive and gram-negative pathogens.

Macrolide and beta-lactam antimicrobial agents are frequently used for the treatment of upper and lower respiratory tract infections and skin or skin structure infections. To evaluate the relative in vitro activity of these antimicrobial drugs against organisms commonly involved in these infections, we tested clarithromycin, erythromycin, cefprozil, cefuroxime, cefaclor, cephalexin, amoxicillin, amoxicillin/clavulanate, and doxycycline against 174 gram-positive and gram-negative clinical isolates, including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, group A beta-hemolytic streptococci, alpha-hemolytic streptococci, Escherichia coli, and Klebsiella pneumoniae. Manual broth microdilution susceptibility testing was used with a standard inoculum of 5 x 10(4) colony-forming units/well at pH of 7.2. Clarithromycin was the most active agent against streptococci. Methicillin-susceptible S aureus exhibited resistance to both clarithromycin and erythromycin, but was susceptible to cefprozil, cefuroxime, amoxicillin/clavulanate, and doxycycline. Cefprozil was at least as active as cefuroxime, cefaclor, and cephalexin against all organisms tested, but was fourfold less active than doxycycline against E coli and 16-fold less active than clarithromycin versus S pneumoniae. The gram-negative isolates tested showed resistance to clarithromycin and erythromycin; however, cefprozil was as active as amoxicillin/clavulanate against K pneumoniae and E coli. These results demonstrate that clarithromycin provides superior in vitro activity against common streptococci, while cefprozil, cefuroxime, amoxicillin/clavulanate, and doxycycline provide greater activity against methicillin-susceptible S aureus, K pneumoniae, and E coli. Prospective clinical trials are needed to determine the clinical significance of these findings.

Anti-Bacterial Agents↗
PubMed1996

Efficacy of clarithromycin in eradicating Helicobacter pylori.

We reviewed reports on the efficacy of clarithromycin in eradicating Helicobacter pylori. Reports on dual and 1-week triple therapy that included clarithromycin were analyzed to assess the eradication rates of H. pylori infection. Dual therapy with clarithromycin and a proton pump inhibitor achieved eradication rates of 38%-83%, and 1-week triple therapy with omeprazole, clarithromycin, and other antibiotics achieved eradication rates, of 80%-96%. The incidence of side effects with all regimens was low. Clarithromycin is useful for treatment of H. pylori infection. One-week triple therapy that includes clarithromycin and a proton pump inhibitor effectively eradicates H. pylori.

Anti-Bacterial Agents↗
PubMedDate not supplied

Delayed elevation of international normalized ratio with concurrent clarithromycin and warfarin therapy.

Clarithromycin is rarely reported to cause disturbances in anticoagulation. Theoretically, clarithromycin administered concurrently with warfarin could result in enhanced anticoagulation, since many properties of clarithromycin are similar to those of erythromycin, which interacts with warfarin. A search of the National Library of Medicine produced no published reports of an interaction between the drugs. Erythromycin competitively inhibits hepatic metabolism of warfarin, specifically the R-warfarin enantiomer, by the cytochrome P450 3A3 and 3A4 pathways, resulting in increased prothrombin time and international normalized ratio (INR). Two men, age 61 and 70 years, who received stable warfarin regimens, experienced supratherapeutic elevations in prothrombin time (98.4 and 26.8 sec) and INR (90.3 and 5.6), respectively. While taking warfarin, both patients experienced dramatically increased anticoagulation effects 5 days after starting clarithromycin for atypical pneumonia. They were similarly managed for overanticoagulation by discontinuing clarithromycin, holding warfarin, and receiving intravenous phytonadione. Neither man suffered from medical complications related to anticoagulation. Until clear documentation of the exact mechanism and temporal relationship of this interaction is known, patients receiving warfarin who require the concurrent clarithromycin should have prothrombin time and INR closely monitored.

Aged↗
PubMed1998

Comparison of azithromycin and clarithromycin in their interactions with rifabutin in healthy volunteers.

A 14-day, randomized, open, phase I clinical trial was designed to examine possible pharmacokinetic interactions between rifabutin and two other antibiotics, azithromycin and clarithromycin, used in the treatment of Mycobacterium avium complex infections. Thirty healthy male and female volunteers were divided into five groups of six participants each: 18 received 300 mg/day of rifabutin, 12 in combination with therapeutic doses of either azithromycin or clarithromycin; the remaining 12 received azithromycin or clarithromycin alone. On day 10 the study was terminated because of adverse events, including severe neutropenia. Fourteen participants who received rifabutin developed neutropenia, including all 12 participants who received azithromycin or clarithromycin concomitantly. Analyses of serum revealed no apparent pharmacokinetic interaction between azithromycin and rifabutin. However, the mean concentrations of rifabutin and 25-O-desacetyl-rifabutin (an active metabolite) in participants who received clarithromycin and rifabutin concomitantly were more than 400% and 3,700%, respectively, of concentrations in those who received rifabutin alone. Physicians should be aware that recommended prophylactic doses of rifabutin may be associated with severe neutropenia within 2 weeks after initiation of therapy, and all patients receiving rifabutin, especially with clarithromycin, should be monitored carefully for neutropenia.

Adolescent↗
PubMed1998

[Effectiveness of the eradication of Helicobacter pylori by treatment with omeprazol, amoxicillin, and clarithromycin according to dosage and administration schedule].

BACKGROUND: There are many reports that evaluate the efficacy of the combination of omeprazole, amoxicillin and clarithromycin in the eradication of Helicobacter pylori, but data about effectivity in clinical practice are sparse. The goal of our study is to evaluate the effectivity in the clinical setting of this combination with diverse durations and doses. METHODS: This is a retrospective analysis of 187 patients (128 male and 59 female), with an endoscopic diagnosis of duodenal ulcer (156), gastric ulcer (25) and both (6) with Helicobacter pylori infection as defined by both: a positive ureasa test and histology. After diagnosis the patient were treated with one of three combinations: a) omeprazole: 20 mg/12 h + amoxicillin: 1 g/12 h + clarithromycin: 500 mg/12 h, during 6 days (n = 60); b) omeprazole: 20 mg/12 h + amoxicillin: 1 g/12 h + clarithromycin: 500 mg/12 h, during 7 days (n = 74), and c) omeprazole: 20 mg/12 h + amoxicillin: 1 g/8 h + clarithromycin: 500 mg/8 h, during 7 days (n = 53). After the 6 or 7 day treatment period the patients did not receive any further treatment until a follow-up control unit. Eradication was evaluated with one of two tests: endoscopy (with ureasa test and at least 4 histologic samples) (n = 90) or urea breath test according to european protocol (n = 97). RESULTS: No patient dropped out because of side effects and compliance was above 80% in all cases. The global eradication rate was 87.2% (CI 95%: 82.4-92%). According to treatment the rate were respectively 80% (CI 95%: 67.7-89.2%) with scheme A; 89.2% (CI 95%: 79.8-95.2%) with scheme B, and 92.5% (CI 95%: 81.8-97.9%) with scheme C, with no statistically significant differences among groups. Difference between schemes and C, however, was almost reached (p = 0.053). CONCLUSIONS: The combination of omeprazole, amoxicillin and clarithromycin at standard doses (scheme B) is effective in clinical practice. Higher dose of amoxicillin and clarithromycin does not improve the results, and shorter duration of therapy associated with lower, although not significant rate of eradication.

Adult↗
PubMed2001

Comparison of 5-day, short-course gatifloxacin therapy with 7-day gatifloxacin therapy and 10-day clarithromycin therapy for acute exacerbation of chronic bronchitis.

BACKGROUND: The ideal duration of antibiotic therapy for acute exacerbation of chronic bronchitis (AECB) remains controversial. OBJECTIVE: This study compared short-course, 5-day gatifloxacin treatment with standard 10-day clarithromycin treatment in patients with AECB; 7-day gatifloxacin therapy was a secondary comparator. METHODS: This was a multicenter, prospective, randomized, double-blind study in which adult outpatients with AECB were randomized to 1 of 3 treatment groups: 5 days of gatifloxacin, 7 days of gatifloxacin, or 10 days of clarithromycin. Clinical cure and microbiologic eradication rates were determined 7 to 14 days after the completion of antibiotic treatment. RESULTS: A total of 527 patients with AECB were enrolled and treated with study drug (174, gatifloxacin 5-day; 175, gatifloxacin 7-day; 178, clarithromycin 10-day). Most patients (82%) had type 1 (severe) exacerbations, and a bacterial pathogen was isolated from pretreatmer, sputum samples in 59% of patients. The overall clinical cure rates among clinically evaluable patients were comparable between groups: 89% (135/151 patients) in the gatifloxacin 5-day group; 88% (136/154) in the gatifloxacin 7-day group; and 89% (145/163) in the clarithromycin 10-day group. The 95% CIs for the differences in response rates were -6.1 to 7.0 for gatifloxacin 5-day versus clarithromycin, -8.9 to 5.0 for gatifloxacin 7-day versus clarithromycin, and -5.5 to 8.0 for gatifloxacin 5-day versus 7-day. These observations did not appear to be affected by use of corticosteroids or smoking status, type of exacerbation, or duration of current episode. The microbiologic eradication rate among microbiologically evaluable pathogens was >90% in all treatment groups. No clinically meaningful differences were noted in the incidence of drug-related adverse events. CONCLUSION: Short-course, 5-day gatifloxacin therapy in patients with AECB resulted in clinical cure and microbiologic eradication rates comparable to those of standard 7- and 10-day therapies.

Acute Disease↗
PubMed2003

Mutations in the 23S rRNA gene are associated with clarithromycin resistance in Helicobacter pylori isolates in Brazil.

BACKGROUND: Resistance of Helicobacter pylori to clarithromycin has been associated with A2142G and A2143G point mutations in the 23S rRNA gene. Thus, the purpose of the present study was to determine the prevalence of each mutation in 52 clarithromycin-resistant H. pylori strains and to characterize the influence each type of mutation on the MIC. METHODS: The MIC for clarithromycin was determined by the agar dilution method, and the point mutations of H. pylori were detected by PCR followed by restriction fragment length polymorphism. RESULTS: Clarithromycin MICs ranged from 2 to >256 microgram ml-1 among the 52 strains included in this study. Both the A2142G and the A2143G mutations were present in 94.2% of clarithromycin-resistant H. pylori strains examined. A relationship was observed between the presence of the A2142G mutation and the highest MIC values (p = 0.01). CONCLUSION: In an H. pylori-infected population, the A2142G mutation may incur to a greater probability of treatment failure if clarithromycin is used.

Journal Article↗
PubMed2002

Clarithromycin synergism with essential and trace elements.

In order to ascertain the role of various essential and trace element complexation on the antibacterial activity of various macrolide antibiotics, the synergistic or antagonistic behavior of clarithromycin metal complexes has been studied and compared with the parent drug. Metal complexes of clarithromycin with magnesium, calcium, chromium, manganese, iron, cobalt, nickel, copper, zinc and cadmium has been investigated for their antibacterial activity and compared with clarithromycin by observing the changes in minimum inhibitory concentration (MIC) and by measuring the zone of inhibition. of complexes against both gram negative and gram positive microorganisms. Various microorganisms used were Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Salmonella typhii, Proteus vulgaris, Shigella dysentary, Kelebcilla pneumoni and Staphylococcus epidermidis. For MIC observation, serial dilution method was employed and zone sizes were determined by diffusion disk method. Our investigations divulge that formation of clarithromycin complexes results in synergistic effect i.e., antimicrobial activity of complexes of clarithromycin increases with respect to parent clarithromycin drug and MIC of drug metal complexes decreased.

Journal Article↗