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PubMed2000

Clarithromycin for Helicobacter pylori infection.

Helicobacter pylori, a Gram-negative organism that survives in the deep mucus layer and attaches to the gastric surface cells, is estimated to be present in up to one-half of the US population. Chronic H. pylori infection causes chronic gastritis, peptic ulcer diseases and even gastric cancer. Cure of the infection leads to healing of gastric inflammation, prevention of development of peptic ulcer, as well as accelerated healing of peptic ulcers, and prevention of ulcer recurrence. Treatment of H. pylori has undergone substantial evolution over the past decade. Despite the in vitro susceptibility, results from single or even dual drug therapy is typically unsatisfactory and the best therapy is yet to be defined. The best current therapies for H. pylori infection consist of a proton pump inhibitor (PPI) or ranitidine bismuth citrate and two antibiotics (triple therapies), or bismuth, tetracycline, metronidazole and a PPI (quadruple therapy). Clarithromycin is one of the most useful antimicrobials against H. pylori. It is an acid-stable macrolide with a broad spectrum of antibacterial activity, well absorbed with a wide tissue distribution and with mild side effects. Clarithromycin has a low minimum inhibitory concentration (MIC50) for H. pylori and its effect is potentiated by acid inhibition. When combined with a PPI or ranitidine bismuth citrate and amoxicillin or metronidazole, eradication rates of more than 95% can be achieved with susceptible organisms. However, the prevalence of primary and acquired clarithromycin resistance, which is due to mutations within a conserved loop of 23S rRNA of H. pylori, is increasing. In practice, the presence of clarithromycin resistance usually implies reduced success when clarithromycin-containing regimes are used. There is a need for improved therapies for H. pylori where antibiotic resistance is less of a problem.

Anti-Bacterial Agents↗
PubMed2005

Clarithromycin extended-release in community-acquired respiratory tract infections.

Clarithromycin extended-release (ER) is a second-generation macrolide with bactericidal activity against a broad group of pathogens. It allows for convenient once-daily dosing (2 x 500 mg/day), and has less severe adverse effects than the immediate-release (IR) formulation of the drug, which may result in improved patient compliance. Clarithromycin ER has been approved for the treatment of community-acquired pneumonia, acute maxillary sinusitis and acute bacterial exacerbation of chronic bronchitis. In comparison to the IR formulation, clarithromycin ER demonstrates prolonged absorption from the gastrointestinal tract, allowing for once-daily dosing with improved gastrointestinal tolerability. Various double-blind, randomised clinical trials and group studies have found clarithromycin ER to be an efficacious treatment option, comparable with clarithromycin IR, or its other competitors.

Clarithromycin↗
PubMed2003

Clarithromycin (Biaxin) extended-release tablet: a therapeutic review.

Clarithromycin (Biaxin) extended-release tablets, an advanced generation macrolide, were recently introduced into the USA for the treatment of acute exacerbations of chronic bronchitis, community-acquired pneumonia and acute maxillary sinusitis. The reformulation is intended to improve both patient compliance and tolerability. The extended-release tablets allow convenient once-daily dosing (1000 mg). The extended-release formulation has been shown to be equivalent to the immediate-release formulation concerning area under the plasma concentration time curve. In comparative clinical trials for acute exacerbations of chronic bronchitis, community-acquired pneumonia and acute maxillary sinusitis, clarithromycin extended-release tablets were equivalent to the immediate-release formulation concerning clinical efficacy and bacterial eradication, with improved gastrointestinal tolerability. Similar efficacy and gastrointestinal tolerability results were demonstrated in a recent comparative study of clarithromycin extended-release formulation and amoxicillin-clavulanate in patients with acute exacerbations of chronic bronchitis. Clarithromycin extended-release 1000 mg daily has also been shown to be equivalent to levofloxacin 500 mg daily for the treatment of community-acquired pneumonia in a recent study. The macrolide class of antimicrobials, including clarithromycin extended-release, continues to be a safe and efficacious choice for the out-patient management of community-acquired bacterial respiratory tract infections.

Anti-Bacterial Agents↗
PubMed1999

Potential interaction between itraconazole and clarithromycin.

Three patients negative for human immunodeficiency virus infection were admitted for pulmonary Mycobacterium avium complex (MAC) and aspergillosis infections. They were treated with different drug combinations, but all regimens included clarithromycin for MAC and itraconazole for aspergillosis. All patients experienced an increase in clarithromycin concentrations and clarithromycin: 14-OH-clarithromycin ratio compared with expected range values. They had no clinical side effects. The time course suggested a possible interaction between clarithromycin and itraconazole, presumably through itraconazole's effects on cytochrome P450 3A4 activity. A bidirectional interaction cannot be ruled out. The data suggest that, when necessary, these two drugs can be administered together safely. Further investigation is necessary to determine the extent and clinical consequences of coadministration in humans.

Adult↗
PubMed2002

Serum bactericidal activity of extended-release clarithromycin against macrolide-resistant strains of Streptococcus pneumoniae.

STUDY OBJECTIVE: To investigate the serum bactericidal activity (SBA) over time of extended-release clarithromycin against moderately resistant strains of Streptococcus pneumoniae. DESIGN: Prospective, single-dose pharmacodynamic study. SETTING: University-affiliated research center. SUBJECTS: Eleven healthy male volunteers. INTERVENTION: All volunteers received a single dose of extended-release clarithromycin as two 500-mg tablets, and blood samples were obtained at 0, 2, 6, 12, and 24 hours after administration of the dose. MEASUREMENTS AND MAIN RESULTS: For each blood sample, a serum bactericidal titer (SBT) was determined against S. pneumoniae strains with minimum inhibitory concentrations (MICs) of 0.5, 1.0, 2.0, 4.0, and 8.0 microg/ml to clarithromycin. The median SBT was determined for each time period. The extended-release formulation of clarithromycin exhibited SBA for 24 hours against pneumococcal strains with MICs of 0.5, 1.0, and 2.0 microg/ml. No SBA was observed against isolates with MICs of 4.0 or 8.0 microg/ml. CONCLUSION: The extended-release formulation of clarithromycin, taken once/day, will provide SBA for 24 hours against strains of S. pneumoniae with MICs of 2.0 microg/ml or less.

Adult↗
PubMedDate not supplied

Retrospective comparison of azithromycin, clarithromycin, and erythromycin for the treatment of foals with Rhodococcus equi pneumonia.

The objective of this retrospective study was to compare the efficacy of azithromycin-rifampin, clarithromycin-rifampin, and erythromycin-rifampin for the treatment of pneumonia caused by Rhodococcus equi in foals. Eighty-one foals with naturally acquired pneumonia caused by R. equi were included in the study. Information on age, sex, breed, physical examination findings, laboratory testing, and thoracic radiography was abstracted from each medical record. Foals were divided in 3 groups based on the antimicrobial agent selected for therapy. Short-term (discharge from the hospital) and long-term (apparently healthy as a yearling) success rates, days of hospitalization, days with fever, days with tachypnea, and percentage of radiographic improvement were compared among groups. Foals treated with clarithromycin-rifampin had significantly (P = .02) higher odds of overall short-term (odds ratio [OR] = 12.2) and long-term (OR = 20.6) treatment success and significantly fewer days with fever than foals treated with erythromycin-rifampin. Foals treated with clarithromycin-rifampin had a significantly (P = .03) higher percentage of radiographic improvement and a tendency (P = .06) toward higher odds of overall short-term (OR = 8.1) and long-term (OR = 11.8) treatment success compared to foals treated with azithromycin-rifampin. Among foals with severe radiographic lesions, the success rates of foals treated with clarithromycin-rifampin both short-term (88%) and long-term (83%) were significantly (P = .02) higher than that of foals treated with azithromycin-rifampin (0%). For each treatment group, the only reported adverse effect was diarrhea that was mild and self-limiting in most cases. The combination clarithromycin-rifampin is superior to azithromycin-rifampin or erythromycin-rifampin for the treatment of pneumonia caused by R. equi in foals in a referral population.

Actinomycetales Infections↗
PubMed1993

Clarithromycin. A review of its pharmacological properties and therapeutic use in Mycobacterium avium-intracellulare complex infection in patients with acquired immune deficiency syndrome.

Results from noncomparative and placebo-controlled studies demonstrate the efficacy of clarithromycin in the treatment of disseminated Mycobacterium avium-intracellulare complex (MAC) infection in patients with acquired immune deficiency syndrome (AIDS). Whether given alone or in combination with other antimycobacterial treatments, doses of 500 to 2000mg (typically 1000mg) administered twice daily are effective in controlling bacteraemia in these patients. Clarithromycin has also been shown to improve clinical symptoms of infection and may improve quality of life in AIDS patients with MAC infection. Clarithromycin is generally well tolerated when used in the doses typically required for the treatment of MAC infection (1000 or 2000 mg/day). Gastrointestinal disturbances are the most commonly occurring adverse events and occur most frequently at dosages of 4000 mg/day. Thus, clarithromycin, as monotherapy or in combination with other antimycobacterial agents, is well tolerated and effectively eradicates MAC from the blood in the short term in patients with AIDS: however, short term monotherapy may lead to bacterial resistance, underscoring the importance of long term treatment with a combination of antimycobacterial agents. While the optimal combination regimen to prevent the development of resistance to antimycobacterial agents. While the optimal combination regimen to prevent the development of resistance to antimycobacterial agents by MAC remains to be determined, clarithromycin will almost certainly be a valuable agent in any such combination.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Mutations in the 23S rRNA gene of Helicobacter pylori associated with clarithromycin resistance.

Among 12 clarithromycin-resistant Helicobacter pylori strains isolated in Guri, Korea, 8 showed an adenine to guanine mutation at position 2143 (formerly A2144G or E. coli 2059) in the 23S rRNA gene by the PCR-restriction fragment length polymorphism (RFLP) method. The remaining 4 strains, digested by neither BsaI nor BbsI, showed a thymine to cytosine mutation at position 2182 (T2182C) by direct sequencing of the PCR products. The T2182C mutants showed a tendency of higher levels of minimum inhibitory concentration to clarithromycin than the A2143G mutants. In conclusion, either the A2143G or the T2182C mutation was present in 100% of clarithromycin-resistant H. pylori isolates examined. The PCR-RFLP technique with restriction enzymes BbsI and BsaI was a rapid and relatively simple method to detect the clarithromycin resistance. But undigested isolates were quite frequent among our isolates (33.3%), the PCR-RFLP method with restriction enzymes BbsI and BsaI should not be used alone, and development of other rapid detection method for clarithromycin resistance is mandatory.

Amino Acid Sequence↗
PubMed1999

The macrolides: erythromycin, clarithromycin, and azithromycin.

In addition to erythromycin, macrolides now available in the United States include azithromycin and clarithromycin. These two new macrolides are more chemically stable and better tolerated than erythromycin, and they have a broader antimicrobial spectrum than erythromycin against Mycobacterium avium complex (MAC), Haemophilus influenzae, nontuberculous mycobacteria, and Chlamydia trachomatis. All three macrolides have excellent activity against the atypical respiratory pathogens (C. pneumoniae and Mycoplasma species) and the Legionella species. Azithromycin and clarithromycin have pharmacokinetics that allow shorter dosing schedules because of prolonged tissue levels. Both azithromycin and clarithromycin are active agents for MAC prophylaxis in patients with late-stage acquired immunodeficiency syndrome (AIDS), although azithromycin may be the preferable agent because of fewer drug-drug interactions. Clarithromycin is the most active MAC antimicrobial agent and should be part of any drug regimen for treating active MAC disease in patients with or without AIDS. Although both azithromycin and clarithromycin are well tolerated by children, azithromycin has the advantage of shorter treatment regimens and improved tolerance, potentially improving compliance in the treatment of respiratory tract and skin or soft tissue infections. Intravenously administered azithromycin has been approved for treatment of adults with mild to moderate community-acquired pneumonia or pelvic inflammatory diseases. An area of concern is the increasing macrolide resistance that is being reported with some of the common pathogens, particularly Streptococcus pneumoniae, group A streptococci, and H. influenzae. The emergence of macrolide resistance with these common pathogens may limit the clinical usefulness of this class of antimicrobial agents in the future.

Adult↗
PubMed2003

Henoch-Schönlein purpura associated with clarithromycin. Case report and review of literature.

OBJECTIVE: To report a case of Henoch-Schönlein purpura that appears to be related to the intake of clarithromycin for pharyngitis/tonsillitis. CASE SUMMARY: We describe a case of Henoch-Schönlein associated with clarithromycin therapy in a 48-year-old white man with no history of allergic drug reactions. Four days after starting therapy, he came to our hospital emergency room because of a non-pruritic palpable purpuric rash on the trunk and extremities and arthralgias involving elbows and knees. Administration of clarithromycin was suspended, in a few days, arthralgias and skin lesions quickly resolved. Three weeks later, the patient presented again with abdominal pain, dark-red urine and swelling of the legs. Urinalysis revealed proteinuria of 11 g/24 h and hematuria. A percutaneous renal biopsy showed a diffuse endocapillary proliferative glomerulonephritis with segmental areas of fibrinoid necrosis within glomeruli, on immunofluorescence study granular deposits of IgA and C3 were present in the mesangium and capillary walls. A diagnosis of HSP was made. We suspected that the causative agent might be clarithromycin since this was the only drug added before the cutaneous and renal condition appeared. CONCLUSIONS: Our case and the previous case suggest that HSP may represent a potential adverse effect of clarithromycin, clinicians should be alerted to this potentially severe side effect of such a widely used drug. In accordance with the data obtained and based on the Naranjo algorithm, the adverse reaction could be considered possible.

Anti-Bacterial Agents↗
PubMed2005

Effect of ketoconazole on the pharmacokinetics and safety of telithromycin and clarithromycin in older subjects with renal impairment.

OBJECTIVE: The objective of this study was to determine the effect of multiple impairments in drug elimination on the pharmacokinetics and pharmacodynamics (effect on QTc interval), using clarithromycin as a comparator. METHODS: Thirty-two subjects aged > or = 60 years with renal impairment who were otherwise medically stable were recruited into this parallel-group study. Following stratification according to creatinine clearance (CL(CR)), subjects were randomized to a five-day treatment with ketoconazole (400 mg once daily) alone, or a five-day treatment with ketoconazole (400 mg once daily) and telithromycin (800 mg once daily) given concomitantly or a five-day treatment with ketoconazole (400 mg once daily) and clarithromycin (500 mg twice daily) given concomitantly. Steady-state pharmacokinetics and safety, including serial electrocardiograms, were assessed. RESULTS: In subjects with CL(CR) 30 - 80 ml/min, the mean maximal telithromycin concentration at steady state (C(max),ss) was 3.6 mg/l and the steady state area under the plasma concentration-time curve from time zero to 24 hours (AUC(0-24 h) ss) was 33.4 mg x h/l. The mean C(max), ss and AUC(0-12 h)ss for clarithromycin were 6.2 mg/l and 56.1 mg x h/l, respectively. The increases in telithromycin C(max) ss and AUC(0-24 h) ss compared to corresponding data for healthy young subjects were 1.6- and 2.7-fold, respectively, whereas corresponding increases for clarithromycin were 2.2- and 3.3-fold, respectively. In the telithromycin plus ketoconazole group deltaQTc values were equal or < 60 ms. All QTc values were equal or < 450 ms in males and equal or < 470 ms in females. CONCLUSIONS: The increase in telithromycin plasma concentrations during ketoconazole-mediated inhibition of CYP3A4 in subjects aged 60 years or older with renal impairment was similar to that for clarithromycin under the same conditions. Telithromycin was well tolerated and produced no clinically significant prolongations in the QTc interval.

Aged↗
PubMed1995

In vivo evaluation of three acid-stable azalide compounds, L-701,677, L-708,299 and L-708,365 compared to erythromycin, azithromycin and clarithromycin.

L-701,677, L-708,299 and L-708,365 are novel azalide derivatives of erythromycin that exhibit improved acid stability over erythromycin, azithromycin and clarithromycin. The half-life in aqueous solution at pH = 2.1 of these compounds ranged from 0.3 hour for erythromycin to 16.2 hours for L-708,299. The rank order of half-life in acid solution from most to least stable was L-708,299 > L-701,677 > L-708,365 > azithromycin = clarithromycin > erythromycin. In a disseminated Streptococcus pyogenes mouse infection model, azithromycin and L-708,365 were slightly more efficacious than clarithromycin, L-701,677 and L-708,299; all 5 compounds being more active than erythromycin. In a Klebsiella pneumoniae pulmonary challenge mouse model, azithromycin, L-701,677, L-708,299 and L-708,365 were all equal in efficacy and at least four-fold more active than clarithromycin and erythromycin. Clarithromycin, L-708,365 and interestingly erythromycin, showed greater bacterial clearance than azithromycin, L-701,677 and L-708,299 in a localized infection model that measured clearance of Staphylococcus aureus from mouse thigh tissues. Our results indicate that L-701,677, L-708,299 and L-708,365 exhibit improved acid stability and were at least equally efficacious as presently marketed macrolide/azalide antibiotics.

Animals↗
PubMed1993

Clinical trial of clarithromycin for cutaneous (disseminated) infection due to Mycobacterium chelonae.

OBJECTIVE: To determine if clarithromycin monotherapy is safe and effective in treating cutaneous disease (especially disseminated disease) due to Mycobacterium chelonae (formerly M. chelonae subspecies chelonae). DESIGN: An open, noncomparative trial of clarithromycin as single-drug therapy. SETTING: Nationwide referrals. PATIENTS: Culture-positive patients whose M. chelonae came from a cutaneous source and whose isolate was submitted to a single referral laboratory for susceptibility testing. INTERVENTION: Clarithromycin, 500 mg twice a day by mouth for 6 months. No attempt was made to alter use of immunosuppressive drugs. MAIN OUTCOME MEASURES: Acid-fast bacilli smears and cultures of skin lesions during and after treatment, with monitoring of clinical response, side effects, and development of new lesions. RESULTS: Fourteen patients (10 with disseminated disease) were enrolled in the study and completed at least 3 months of therapy. Underlying diseases included rheumatoid arthritis, other autoimmune disorders, and organ transplantation. All were taking corticosteroids (93%) or cyclophosphamide (7%). All patients had an excellent response to therapy, with only mild side effects from the drug. Two patients died of other diseases after improving clinically but while still taking medication. One noncompliant patient who prematurely discontinued therapy after 3.5 months relapsed 1 month later with an isolate resistant to clarithromycin. The remaining 11 patients have all completed therapy given for a mean of 6.8 months (range, 4.5 to 9 months). Therapy has been discontinued for 9 of the 11 patients for at least 6 months (mean, 7.1 months; range, 6 to 12 months), with no evidence of relapse. No remaining patient had positive acid-fast bacilli smears or cultures of skin lesions after 1 month of therapy. CONCLUSIONS: Clarithromycin may be the drug of choice for cutaneous (disseminated) disease due to M. chelonae, although more patients with long-term clinical follow-up need to be studied.

Adolescent↗
PubMed2001

[Acute delirium, probably precipitated by clarithromycin].

Clarithromycin is a relatively new antibiotic with many applications. Its frequent use explains why side-effects previously reported seldom now become clear. Two patients, a man aged 74 and a woman aged 56 years, developed delirium after treatment with clarithromycin as part of eradication treatment of Helicobacter pylori, presumably as a result of an ideosyncratic reaction to the clarithromycin. Preclinical and clinical investigations did not reveal side effects on the central nervous system. By now the appearance of a delirium presumably related to the use of clarithromycin has been described in several patients. Furthermore some patients had a positive rechallenge. Finally, 17 reports on psychiatric side effects, of which 7 were delirium, after the use of clarithromycin reached the Netherlands Pharmacovigilance Foundation (Lareb). This combination of facts makes a causal relationship probable.

Acute Disease↗
PubMedDate not supplied

Efficacy and tolerability of ranitidine bismuth citrate plus amoxycillin and clarithromycin as first- or second-line therapy to cure Helicobacter pylori infection.

BACKGROUND/AIMS: Ranitidine bismuth citrate has recently been introduced for the treatment of H. pylori infection and obtains good eradication rates; however, eradication failures still appear in a considerable proportion of cases. The aim of this study was to compare the efficacy and tolerability of ranitidine bismuth citrate plus amoxycillin and clarithromycin as first- or second-line therapy to cure H. pylori infection. METHODOLOGY: We studied 423 consecutive H. pylori-positive patients. In 210 consecutive patients H. pylori infection was diagnosed for the first time (group A), while 213 consecutive patients were enrolled after failure of a first attempt to eradicate H. pylori (group B). All patients received ranitidine bismuth citrate 400 mg b.d. plus clarithromycin 500 mg b.d. and amoxycillin 1 g b.d. for seven days. H. pylori-status was evaluated by means of histology and rapid urease test at entry and by 13C-urea breath test in all patients one month after treatment. RESULTS: 410/423 patients completed the study (202/210 in group A and 208/213 in group B). Two patients of group A and 1 patient of group B were withdrawn from the study due to poor compliance, 6 group A patients and 4 group B patients were lost to follow-up. In group A, after the end of treatment, 181/202 patients were H. pylori-negative (per-protocol analysis: 89.60% [C.I. 95%: 82-95%]; on intention-to-treat analysis: 86.19% [C.I. 95%; 76-92%]), side-effects occurred in 29 patients (13.80%); they were severe in 2 patients and the patients were withdrawn from the study. In group B, after the end of treatment, 200/208 patients were H. pylori-negative (per-protocol analysis: 95.15% [C.I. 95%; 92-100%], on intention-to-treat analysis: 93.89% [C.I. 95%; 89-98%), side-effects occurred in 11 patients (5.13%); they were slight or mild and did not require discontinuation of the treatment. The results of group B were statistically better than group A, both in eradication rate (P < 0.01) as well as both side-effects provoked (P < 0.01). CONCLUSIONS: Ranitidine bismuth citrate-clarithromycin-amoxycillin is more effective when used as second-line therapy rather than when used as first-line therapy; second, ranitidine bismuth citrate-clarithromycin-amoxycillin shows lower and slighter side-effects when used as second-line therapy rather than when used as first-line therapy; finally, the excellent tolerability of ranitidine bismuth citrate + clarithromycin + amoxycillin influences positively the patients' compliance, both as first- and second-line therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2002

Clarithromycin inhibits myometrial contractions in isolated human myometrium independent of stimulus.

Erythromycin has a well-known dual effect on the contractility of the gastrointestinal system and recently has also been shown to inhibit contractions of the rat myometrium. The aim of the present study was to investigate the effects of clarithromycin on oxytocin, prostaglandin F2alpha (PGF2alpha) and KCl-induced contractions of human myometrium in vitro. Myometrial strips were obtained from pregnant women undergoing elective Cesarean section and the strips were suspended in a jacketed organ bath filled with Krebs solution at 37 degrees C (pH 7.4) and continuously aired with 95% oxygen and 5% carbon dioxide. Isometric contractions were measured using a force displacement transducer. Oxytocin, PGF2alpha, KCl and clarithromycin were applied to the tissue bath and the amplitude and frequency of contractions were evaluated at 20-min intervals. Freidmann analysis of variance, Kruskal Wallis and Wilcoxon Rank tests were used for statistical analysis of the data. Clarithromycin dose dependently inhibited the amplitude of contractions independent of the stimulus. Pre-treatment with apamin prevented clarithromycin-induced effects on amplitude and frequency of contractions. We conclude that the macrolide antibiotic clarithromycin may have a direct inhibitory effect on contractions of human myometrium.

Adult↗
PubMed2001

Disposition and functions of clarithromycin in human THP-1 monocytes during stimulated and unstimulated conditions.

The macrolide antibiotics are bacteriostatic agents interfering with protein synthesis but they are taken up by phagocytic cells, e.g. macrophages, neutrophils and fibroblasts which take up infectious organisms into phagosome-lysosomal vaculoes. Recent studies have suggested that these macrolide antibiotics block the spread of infections by mechanisms associated with the inflammation process. Herein is a study with clarithromycin using human THP-1 monocytes, a phagocytic cell which has not been studied to date. Clarithromycin was rapidly taken up by the monocytes (approximately 1%) utilizing both saturable carrier and passive processes at pH 7.4 but was exclusively passive at pH 6.8 and 5.0. The carrier process was energy and temperature dependent and appeared to be linked to certain ion channels. Efflux of the drug was rapid and complete in 1 hr. Intracellular disposition showed 74% in the cell sap and 11% in the nucleus. Upon stimulation with zymogen A or bacteria significant increases of uptake occurred in the isolated lysosome-phagosomes. Examination showed that initially clarithromycin treatment triggered the release of NO, H2O2, IL-1 and TNFalpha from the monocytes, known mediators of inflammation, but also mediators which cause bacterial cell death or apoptosis. The activity of the monocyte marker hydrolytic enzyme NAG was elevated at this time as well as protein kinase C activity. Treatment from 2-4 hr with clarithromycin appeared to reverse this process in that the chemical mediator release was reduced along with the activities of hydrolytic enzymes, e.g. NAG and cathepsin D with no evidence of lipid peroxidation and protective SOD enzyme activity elevation. The latter effects of the antibiotic would be useful in blocking the spread of infection or inflammation from the original site. The normal bacterial static killing effects of clarithromycin was evident at 24 but not 2 hr in both extracellular free bacteria and those bacteria phagocytosed by the THP-1 monocytes.

Clarithromycin↗
PubMed1992

Clarithromycin vs penicillin in the treatment of streptococcal pharyngitis.

BACKGROUND: Streptococcal pharyngitis, caused by group A beta-hemolytic streptococci (GABHS), is among the most common infections seen by primary care physicians. Because the illness can result in rheumatic fever, early eradication of infection is important. Penicillin has been the standard treatment for GABHS pharyngitis for over four decades, but reports of bacteriologic failure with this drug in recent years have led to trials of alternative antimicrobials. METHODS: In this investigator-blind, randomized multicenter trial (30 centers), oral clarithromycin, 250 mg twice daily, or oral penicillin VK, 250 mg three times daily, was given to outpatients > or = 12 years old with GABHS pharyngitis as documented by positive cultures for Streptococcus pyogenes and positive rapid immunoassay tests. The clinical and bacteriologic efficacy of clarithromycin was compared with that of penicillin in the 356 evaluable patients. Safety analysis was performed in all patients who had received at least one dose of the study drug (N = 453). RESULTS: Overall, clinical outcomes were comparable in the two groups. However, more clarithromycin-treated patients than penicillin-treated patients had resolution of sore throat (94% vs 86%, P = .014) and disappearance of pharyngeal erythema and exudate (89% vs 82%, P = .05). Bacteriologic cure rates were higher in clarithromycin-treated patients (95% vs 87%, P = .009). No serious adverse events were observed in either group. CONCLUSIONS: This study suggests that clarithromycin twice daily is as effective and as well tolerated as penicillin in the treatment of streptococcal pharyngitis.

Adolescent↗