High blood pressure. Causes, symptoms, treatments

[Is there a role for calcium antagonists when beta-adrenergic blockade therapy is contraindicated in post-myocardial infarction?].

2017-05-06

Analysis of the extent of and reasons for HCW exposure to pertussis during contact with children with the disease, whether exposures were avoidable (because of the failure to recognize a case or to order or adhere to isolation precautions) or unavoidable (because the case was not recognizable or because another diagnosis was confirmed), and the cost of implementing exposure management.

Both clarithromycin and azithromycin have been shown to have an antibacterial spectrum and pharmacokinetic profile superior to that of erythromycin. The differences between the new compounds, however, may not be that significant. Each is likely to become a first-line therapeutic option in specific instances, which will become better delineated as clinical research on these new macrolides continues.

Netherlands Ministry of Health, Welfare, and Sport, and EU.

Azithromycin is the first of a class of antibiotics classified as azalides. In an initial experiment four cats were given a single dose of azithromycin 5 mg/kg orally (p.o.), followed 2 weeks later by a single intravenous bolus (i.v.) dose of 5 mg/kg. Subsequently, six cats were given [14C]azithromycin p.o. in a single dose of 5.4 mg/kg for the study of tissue distribution and metabolism. In both experiments, serial blood samples were collected and the plasma assayed for unchanged azithromycin to determine various pharmacokinetic parameters. After p.o. administration, bioavailability was 58% and absorption rapid with a tmax of 0.85 +/- 0.72 h and a Cmax of 0.97 +/- 0.65 microgram/mL. The harmonic mean terminal t1/2 after i.v. administration was 35 h. Tissue half-lives varied from 13 h in fat to 72 h in cardiac muscle. Three metabolites were identified in bile. Unchanged azithromycin accounted for 100% of the total radioactivity in lung and skin tissues when assayed. In comparison with other species, the bioavailability in cats is higher than in humans but lower than in dogs. As in the dog, > 50% of the azithromycin-related material in feline bile was unchanged azithromycin.

The experiments were conducted using Calu-3 cells seeded in the apical compartment of 24-well Transwell® inserts. The antibiotics transport was measured in both apical to basolateral (A-B) and basolateral to apical (B-A) directions and the apparent permeability of each antibiotic was calculated.

Frequent scaling in women aged between 40-50 years had positive correlation with chronic periodontitis. The application of antibiotics in conjuction with mechanical debridation, may reflect in the level of resistance of P. gingivalis in patients with chronic periodontal infections. This could suggest periodical antibiotic susceptibility testing is necessary to determine the efficacy of antimicrobial agents if the perfect curing of chronic periodontal diseases after mechanical debridation is meant. Further clinical studies are required to confirm the in vitro results. The only limitation in this study was identification of bacteria to species rather than subspecies level.

Few RCTs on the efficacy of systemic antibiotic therapy in case of GO were found in the literature review. A systemic antibiotic therapy without plaque and calculus removal is not able to reduce gingival overgrowth. The great heterogeneity of diagnostic data and outcomes is due to the lack of precise diagnostic methods and protocols about GO. Future studies need to improve both diagnostic methods and tools and adequate classification aimed to determine a correct prognosis and an appropriate therapy for gingival overgrowth.

A pharmacokinetic/pharmacodynamic (PK/PD) analysis is important in antibiotic chemotherapy. Basically, the in vivo efficacy of antibiotics that exert concentration-dependent effects can be predicted using conventional PK/PD indices such as the ratio of the area under the curve to the minimum inhibitory concentration (AUC/MIC) and/or the ratio of the maximum plasma concentration to MIC (Cmax/MIC), whereas that of antibiotics with time-dependent effects can be determined using the period of time for which the drug concentration exceeds the MIC (time above MIC [TAM]). However, an optimal PK/PD index remains to be established for some antibiotics. Thus, a PK/PD model which describes the PK profile and effect of an antibiotic was developed, and the results obtained from this model were interpreted to form a PK/PD index map to assess the optimal PK/PD index for the antibiotic. The findings from the map were generally consistent with clinical outcomes even for the antibiotics which proved to be exceptions to the conventional classification. For example, AUC/MIC was an optimal index for azithromycin despite its time-dependent bactericidal activity, and Cmax/MIC was a poor index for arbekacin despite its concentration-dependent profile. Thus, the map would be useful for selecting the appropriate PK/PD index for an antibiotic.

Of the 1022 children 240 (23.4%) harboured S. pneumoniae, 162 (15.8%) H. influenzae, 30 (2.9%) S. pyogenes and 82 (8%) M. catarrhalis in their oropharynx. For S. pneumoniae overall 17.9 per cent of the isolates were intermediately and 7 per cent were resistant to penicillin and resistance to erythromycin trimethoprim-sulphamethoxasole (TMP/SMX), and chloramphenicol was 13.7, 9.1 and 1.6 per cent, respectively. Ampicillin resistance observed in 20.9 per cent of H. influenzae isolates was associated with the presence of beta-lactamase, except two isolates interpreted as beta-lactamase-negative ampicillin resistant strains. Resistance of H. influenzae to TMP/SMX, chloramphenicol, azithromycin, cefaclor and amoxicillin/clavulanic acid was 14.2, 2.4, 1.8, 1.2 and 1.2 per cent, respectively. M.catarrhalis isolates produced beta-lactamase in 80.5 per cent of the cases and all were susceptible to macrolides and clavulanic acid/amoxicillin combination; the highest rate of resistance of 17 per cent was for TMP/SMX. One (3.3%) isolate of S. pyogenes was resistant to macrolides tested.