Combination Of Nafcillin Research Articles

Myelosuppression Rates with Administration of Nafcillin with and without Rifampin in Pediatric Patients.

Myelosuppression, a potential adverse reaction of nafcillin and rifampin, is rarely documented in pediatric populations. The objective of this study is to describe the incidence of myelosuppression in pediatric patients receiving nafcillin or a combination of nafcillin and rifampin therapy. This retrospective chart review identified patients who received nafcillin alone or in combination with rifampin. The primary endpoint was the incidence of myelosuppression as a composite outcome. The secondary endpoints were the incidence of thrombocytopenia, anemia, and neutropenia individually. Of 199 patients in this study, 98 received nafcillin alone. There was no difference in the rates of myelosuppression between patients receiving nafcillin alone or in combination with rifampin (p = 0.0763), and the use of combination therapy did not affect the development of neutropenia (p = 0.2764) or thrombocytopenia (p = 0.1672). Patients receiving combination therapy were more likely to be anemic at the end of therapy (odds ratio [OR] = 2.333, 95% confidence interval [CI] 0.999, 5.446). Similarly, patients receiving longer durations of nafcillin were more likely to experience anemia (OR 1.774, 95% CI 1.382, 2.370) and neutropenia (OR 1.256, 95% CI 1.024, 1.540). The use of nafcillin does not significantly affect myelosuppression in pediatric patients, although longer durations of therapy may result in increased rates of neutropenia and anemia. Combination therapy with rifampin may result in increased rates of neutropenia.

Relationship between in vitro antimicrobial sensitivity of bovine subclinical mastitis isolates and treatment outcome in lactating dairy cows

Summary The objective of the present study was to determine whether there was an association between the in vitro antimicrobial sensitivity test results of subclinical mastitis pathogens and bacteriological cure following intramammary treatment using a combination of nafcillin, penicillin, and streptomycin (NPS). Eighty-six intramammary pathogens from 43 cows were examined in this study. Most intramammary infections were due to coagulase-negative staphylococci, coliforms, and environmental streptococci. The antibiotic sensitivity to NPS was determined using the Kirby-Bauer disc diffusion method. Bacteriological cure rates for sensitive, intermediate, and resistant isolates in the standard treatment group (3 intramammary infusions of NPS once daily) were 84.4, 88.9, and 100%, respectively. These figures in the extended treatment group (6 intramammary infusions of NPS once daily) were 100% for the 3 categories. Bacteriological cure was not associated with the sensitivity test result. Based on this study, Kirby-Bauer sensitivity test results were not useful as predictors of the bacteriological outcome of subclinical mastitis treated with intramammary NPS.

Successful Therapy of Experimental Endocarditis Caused by Vancomycin-Resistant Staphylococcus aureus with a Combination of Vancomycin and β-Lactam Antibiotics

VRS1 is the first isolated strain of vancomycin-resistant Staphylococcus aureus (VRSA) found to carry the vanA gene complex previously described in Enterococcus. Under vancomycin pressure, VRS1 makes aberrant cell walls consisting of stem tetrapeptide and depsipeptide that lack the terminal D-Ala-D-Ala residues targeted by vancomycin. Previous data have suggested that this aberrant cell wall is not cross-linked by PBP2a, the enzyme responsible for cell wall transpeptidation in the presence of beta-lactam antibiotics. We examined the efficacy of treating VRS1 with a combination of vancomycin and beta-lactam antibiotics in vitro and in vivo. We found that the MIC of oxacillin for VRS1 decreased from >256 microg/ml to <1 microg/ml in the presence of vancomycin. Using the rabbit model of endocarditis, we treated VRS1-infected rabbits with nafcillin alone, vancomycin alone, or a combination of nafcillin and vancomycin. Treatment with nafcillin in combination with vancomycin cleared bloodstream infections within 24 h and sterilized 12/13 spleens (92%), as well as 8/13 kidneys (62%), following 3 days of treatment. Mean aortic valve vegetation counts were reduced 3.48 log(10) CFU/g with the combination therapy (compared to untreated controls) and were significantly lower than with either vancomycin or nafcillin given alone. VRS1 was extremely virulent in this model, as no untreated rabbits survived the 3-day trial. Treatment of clinical infections due to VRSA with the combination of vancomycin and beta-lactams may be an option, based on these results.

Staphylococcal Infections

Staphylococcal Infections

Staphylococcal Infections

Staphylococcal Infections

Antibiotic treatment of osteomyelitis: what have we learned from 30 years of clinical trials?

To determine the most appropriate approach to antibiotic therapy for osteomyelitis, the medical literature for articles published from 1968 to 2000 was reviewed. Ninety-three clinical trials in children and adults were identified using almost every antibiotic class. Most studies were non-comparative and the comparative trials involved relatively few patients. Publications generally did not provide clinically important information regarding infection staging or classification, surgical treatment provided, or the presence of orthopedic hardware. The median duration of follow-up after treatment was only 12 months. The clinical outcome was better for acute than chronic osteomyelitis in eight of the 12 studies allowing comparison. In the comparative trials, few statistically significant differences were observed between the tested treatments. In one small trial, the combination of nafcillin plus rifampin was more effective than nafcillin alone. In pediatric osteomyelitis, oral therapy with cloxacillin was more effective than tetracycline in one study, and oral clindamycin was as effective as parenteral anti-staphylococcal penicillins in another. In several investigations oral fluoroquinolones were as effective as standard parenteral treatments. Although the optimal duration of antibiotic therapy remains undefined, most investigators treated patients for about six weeks. Despite three decades of research, the available literature on the treatment of osteomyelitis is inadequate to determine the best agent(s), route, or duration of antibiotic therapy.

Enhancement of the effects of anti-staphylococcal antibiotics by aminoglycosides.

The in vitro activity of seven anti-staphylococcal antibiotics alone and in combination with four aminoglycoside antibiotics against 35 clinical isolates of Staphylococcus aureus from blood cultures of patients with endocarditis or septicemia was studied. The combination of nafcillin-gentamicin or nafcillin-tobramycin when compared with nafcillin alone killed significantly more S. aureus at 6 h for 33 of 35 isolates. A significant decrease in viable colony-forming units at 24 and 48 h was demonstrated for a smaller number of isolates. Using the agar dilution antibiotic susceptibility test, significant enhancement of activity was demonstrated against almost all isolates when cephalothin, cefazolin, or clindamycin was combined with gentamicin, tobramycin, or kanamycin. The combination of nafcillin or vancomycin with gentamicin, tobramycin, or kanamycin also showed enhanced activity against the majority of isolates. Oxacillin or methicillin when combined with the aminoglycosides showed enhancement of activity against the least number of isolates. Streptomycin was the least effective of the four aminoglycoside antibiotics studied.