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The in vitro synergistic activities of moxalactam, cefoperazone, or cefotaxime in combination with amikacin or piperacillin were compared against aminoglycoside-susceptible and aminoglycoside-resistant isolates of Pseudomonas aeruginosa and Serratia marcescens by the checkerboard agar dilution method. All antimicrobial combinations demonstrated some synergy, and no antagonism was observed. Moxalactam plus amikacin and piperacillin plus amikacin were most frequently synergistic (two-thirds of the isolates inhibited synergistically by each combination), whereas combinations of moxalactam, cefotaxime, or cefoperazone with piperacillin were synergistic against only 18 to 25% of the isolates. Moxalactam plus amikacin was the combination most often synergistic for amikacinsusceptible P. aeruginosa, and piperacillin plus amikacin was the combination most frequently synergistic for amikacin-resistant P. aeruginosa and amikacinsusceptible S. marcescens. These results demonstrate frequent in vitro synergistic activity between the new beta-lactam agents and amikacin (especially moxalactam or piperacillin with amikacin), but comparative clinical trials are needed to establish the relative efficacy and toxicity of these combinations.Although well-controlled, definitive clinical studies are lacking, several animal and human studies suggest that Pseudomonas aeruginosa and Serratia marcescens infections may be favorably influenced by treatment with synergistic antimicrobial combinations consisting of an aminoglycoside plus carbenicillin or ticarcillin (1,9,16,17,22). However, the usefulness of these specific combinations has been recently curtailed by the increasing resistance of P. aeruginosa and S. marcescens to carbenicillin and ticarcillin and even to some of the aminoglycosides (18,20,21). Furthermore, a history of a severe allergic reaction to penicillin usually prohibits the use of carbenicillin or ticarcillin.Moxalactam, cefoperazone, and cefotaxime are three new beta-lactam antimicrobial agents with remarkably wide spectra of in vitro antibacterial activity that include most P. aeruginosa and S. marcescens isolates as well as Escherichia coli, Klebsiella spp., Enterobacter spp., Proteus mirabilis, indole-positive Proteus spp., and Bacteroides fragilis (10). These drugs also have inhbitory activity for many strains resistant to carbenicillin, ticarcillin, and the aminoglycosides (6,11,12). Whereas numerous previous studies have focused on the in vitro effectiveness of moxalactam, cefoperazone, and cefotaxime as single agents and their enhanced antibacterial activity over presently available beta-lactam agents, there is a relative paucity of infornation on the relative synergistic activity of these drugs with aminoglycosides or other beta-lactam agents against recent clinically significant bacterial isolates. Thus, we compared the in vitro synergistic activity of moxalactam, cefoperazone, or cefotaxime in combination with amikacin or piperacillin against aminoglycoside-susceptible and aminoglycoside-resistant P. aerugino...

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The in vitro activities of four new beta-lactam antimicrobial agents (moxalactam, cefotaxime, cefoperazone, and piperacillin) and the aminoglycosides against 744 recent clinical isolates of facultative gram-negative bacilli were compared simultaneously by the agar dilution method. The major in vitro difference of these newer beta-lactam compounds appeared to be their antipseudomonal activity; cefoperazone was the most active, whereas cefotaxime had the least potency. The aminoglycosides, however, had the most effective in vitro activity on a weight basis against Pseudomonas aeruginosa.Moxalactam, cefotaxime, cefoperazone, and piperacillin are four new beta-lactam antibiotics developed in the past few years with a wide spectrum of activity against gram-negative bacilli. Preliminary testing has suggested that these new beta-lactam antibiotics possess a broad spectrum of in vitro activity against most clinically important gram-negative bacteria, including Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens, Enterobacter species, and Bacteroides fragilis. Indeed, the potential clinical usefulness of these new betalactam antibiotics appears to be related to a wider spectrum of activity than other beta-lactam antibiotics and lower toxicity than the aminoglycoside drugs. Several previous in vitro studies (1,5,8,10,11,14)

This study presents data relative to the efficacy and safety following the continuous use of oral acyclovir in the treatment of genital herpes over a 5-year period. In this study, 1,146 patients (53% males; 47% females) were originally enrolled. These included patients with a history of frequently recurring genital herpes (mean > 12 episodes per year). During the first year, patients were randomized between those receiving 400 mg of acyclovir twice daily and an equal number receiving placebo. Additionally, acyclovir was utilized for episodic treatment (ES) in both groups. Thereafter, patients received open-label acyclovir suppressive therapy for the remainder of the study period. Complete data are available on 389 patients who completed the fifth year of therapy. All the participants who completed the fifty year of the study had completed either 4 or 5 years of daily suppressive acyclovir therapy. During the first year, a significant decrease in the frequency of recurrences in patients receiving continuous acyclovir (SS) was noted as compared to the placebo group (1.7 vs. 12.5 recurrences; P < 0.0001). From year one to the end of year three, a progressive decrease in the frequency of recurrences was noted in both groups. Yet, those patients who had received SS for the full 3 years had significantly fewer recurrences than those who had received ES in the first year (P = 0.05). During years four and five, the decrease in frequency of recurrences between the ES and SS groups was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)