[Which antibiotics should one choose for prophylaxis in vascular surgery?]

Although the principle and duration of prophylactic antibiotic therapy in prosthetic vascular surgery are fairly widely accepted, the choice of antibiotic is still open to discussion. During two successive periods, identical groups of patients received peri-operative prophylaxis with, during period I (455 cases) oxacillin alone and during period II (537 cases) combined treatment with oxacillin and amikacin. The aim of the study was to evaluate efficacy of the association and to draw general conclusions on choice of antibiotic. The addition of amikacin reduced frequency of infection in elective operations, particularly aorto-ilio-femoral prostheses (0.5% as against 1.24%), but not in operations conducted as emergencies. In addition, frequency of infection due to BGN fell only slightly. Finally, combined therapy with oxacillin-amikacin had 2 disadvantages: impossibility of using these antibiotics for prophylaxis alone as provided for in the protocol, and its high cost. Factors of choice of antibiotic should be: efficacy against germs encountered, which can vary from year to year, rarity of toxic or side effects, good tissue diffusion, the rare need for therapeutic use and a low cost.

Antibiotic prophylaxis for major maxillocraniofacial surgery

A shortened prophylactic regimen of antibiotics for maxillofacial and craniofacial surgery is evaluated. Eighty-five patients were divided into two groups on the basis of the type of incision used. Forty-nine patients undergoing intraoral procedures received penicillin perioperatively and were given one postoperative dose (regimen A). Thirty-six patients undergoing extraoral or combined intraoral and extraoral procedures received penicillin and oxacillin perioperatively, with nine receiving one postoperative dose and 27 receiving an average of seven postoperative doses (regimen B). One infection was observed in the regimen A group, and three were observed in the regimen B group. This infection rate compares favorably to that encountered in the authors' previously reported study on longer prophylactic courses of antibiotics.

Double-blind, placebo-controlled study of oxacillin combined with rifampin in the treatment of staphylococcal infections

A total of 101 patients with proven Staphylococcus aureus infection were included in a double-blind, placebo-controlled study; this study compared oxacillin (12 g/day, intravenously) or vancomycin (2 g/day, intravenously) plus rifampin (1,200 mg/day, orally) with oxacillin or vancomycin plus placebo. We evaluated 65 patients. Of the patients tested, 33 received oxacillin plus rifampin (13 bacteremias), and 32 received oxacillin plus placebo (16 bacteremias). Clinical cure was achieved in 61% of the patients treated with oxacillin plus rifampin and in 56% of the patients treated with oxacillin plus placebo. Improvement was noted in 27 and 25%, respectively, and failure occurred in 9 and 18%, respectively. These differences were not statistically significant. Bacteriological failure occurred in 3 and 28%, respectively (P less than 0.05). None of the failures within the rifampin-treated group was associated with the emergence of a rifampin-resistant mutant. The rates of superinfection were similar in both groups. The geometric means of the serum bactericidal activity after 1, 6, and 11 h were, respectively, 22, 17, and 9 after treatment with oxacillin plus rifampin and 25, 3.4, and 2.3 after treatment with oxacillin plus placebo. It was suggested that the addition of rifampin to oxacillin or vancomycin might only be beneficial to severely ill patients.

[Peritonitis in renal failure patients treated by continuous ambulatory peritoneal dialysis. Treatment by intraperitoneal administration of a group M penicillin]

From February 1980 to February 1983, 55 patients with chronic renal failure were put on continuous ambulatory peritoneal dialysis. Eighty-four episodes of peritonitis occurred., i.e one episode every 9.9 months of treatment. Since staphylococci accounted for 58% of the germs identified, intraperitoneal therapy with a penicillin M was instituted while dialysis was continued through chambers. Cure was obtained in 85.7% of all episodes, either with the penicillin M alone (57% of the cases) or after adjustment of the antibiotic therapy to bacteriological results (28.6% of the cases). Dialysis was discontinued in 10 patients (18%) on account of the peritonitis. The duration of hospital stay for peritonitis was 3.6 days per patient per year. These results were compared with those obtained by other groups. The advantages of penicillin M are its ease of administration, its narrow spectrum and high activity against the pathogens most commonly encountered, and its very low toxicity.

Meningitis due to Staphylococcus aureus

A retrospective analysis of 10 adult patients with community-acquired Staphylococcus aureus meningitis was performed in order to elucidate the characteristics and treatment of this lethal disease. In all patients, a focus of infection outside the central nervous system was apparent at presentation. A poor prognosis was associated with severe underlying disease, greater degree of hyponatremia at presentation, development of seizures, failure of nuchal rigidity to develop, persistent or recurrent bacteremia, and the presence of concurrent S. aureus bronchopneumonia. Degree of deterioration in mental status and cerebrospinal fluid pleocytosis, protein levels, and glucose levels did not appear to have any prognostic significance. Therapy with rifampin and a semisynthetic penicillin effected a cure in all six patients treated with this regimen. In contrast, three of four patients treated with other antibiotic combinations died. On the basis of this experience, it is concluded that further trials with rifampin in combination with another anti-staphylococcal antibiotic for the treatment of S. aureus meningitis are warranted.

[Advantages and hazards of preventing infection following cesarean section--clinical and bacteriologic results of a high-dosage treatment with mezlocillin and oxacillin short-term preventive following clamping of the umbilical cord]

Between August 1980 and August 1981 a prospective randomised study was conducted at the Krankenhaus Nordwest , Dept. of OBGYN , Frankfurt, to investigate the efficacy of a short term prophylaxis using mezlocillin and oxacillin ( Optocillin ) in reducing infections after Caesarean section (6 gs Optocillin after clamping the umbilical cord and after 8 and 16 hours, respectively). Both the study group (sg) and the control group (cg) consisted of 50 patients each. Both groups were statistically homogeneous . Infections were significantly reduced by the prophylaxis: sg 26%/cg 64% - p less than 0,001, febrile morbidity: sg 10%/cg 38% - p less than 0,001, endometritis: sg 6%/cg 20% - p less than 0,08, UTI: sg 18%/cg 36% - p less than 0,05, wound infections: sg 2%/cg 18% - p less than 0,02. Severe infections, however, were seen in neither group. The duration of infections was shorter in the sg. The various postoperative infections were associated with different risk factors (rf) - endometritis: green amniotic fluid, operating time greater than 75 min; cervical dilatation less than 2 cm, UTI: PROM (greater than 6 hs), operating time less than 75 min, internal monitoring, cervical dilatation greater than 2 cm, wound infections: green amniotic fluid, internal monitoring, frequent vaginal examinations (greater than 6), cervical dilatation greater than 2 cm and operating time greater than 75 min. The prophylaxis was especially effective in the presence of the following rfs: green amniotic fluid, internal monitoring, frequent vaginal examinations (6), operating time greater than 75 min and when associated with combined rfs. The reduction of wound infections following the prophylaxis can be ascribed to the elimination of organisms (Staph. spec., enterococci,) at the site of operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Apparent oral contraceptive failure associated with antibiotic administration

The concomitant use of antibiotics and oral contraceptives should be included in the assessment of contraceptive failure. A case of unwanted adolescent pregnancy during the use of a semisynthetic penicillin and an oral contraceptive is presented and discussed. Advising a different contraceptive method or an additional contraceptive modality may be indicated in adolescents taking long-term antibiotic medication.

Antibiotic and clavulanic acid treatment of subcutaneous abscesses caused by Bacteroides fragilis alone or in combination with aerobic bacteria

A subcutaneous abscess model was utilized in investigating the usefulness of various antimicrobial combinations in the treatment of mixed aerobic-anaerobic infections in mice. The infected animals were treated for seven days with single or combined antimicrobial therapy. The single agents used were penicillin, clavulanic acid, oxacillin, metronidazole, and gentamicin. The antimicrobial combinations used were penicillin plus clavulanic acid and metronidazole plus penicillin, oxacillin, or gentamicin. Administration of a single agent was effective in treating abscesses caused by a single susceptible organism. The only effective therapies for mixed infections were the combinations of penicillin plus clavulanic acid or metronidazole plus gentamicin. This study demonstrated the efficacy of penicillin and clavulanic acid in the treatment of infections caused by Bacteroides fragilis alone or in combination with beta-lactamase-producing aerobic bacteria.

[Penetration of mezlocillin and oxacillin into the glandular and adipose tissue of the breast after simultaneous intravenous infusion. A pharmacokinetic study]

The concentrations of mezlocillin and oxacillin were measured after simultaneous intravenous infusion of 4 and 2 g respectively in serum, fat and mammary gland tissue of 35 patients. The maximum mean concentrations of mezlocillin were measured in serum with 281 micrograms/ml and in fat with 38 micrograms/g after the end of the infusion and in the mammary gland with 52.3 micrograms/g after 90 minutes. Mezlocillin concentrations of less than or equal to 2.0 micrograms/ml and g respectively were found after 6-8 hours after the end of the infusion. The maximum mean concentrations of oxacillin were measured in the serum with 107.8 micrograms/ml also after the end of the infusion, declining to levels less than or equal to 2.0 micrograms/ml within 6 hours. Measurable oxacillin-concentrations could not be found in the fat and in the tissue of mammary gland with the chosen dose. The clinical relevance of the results is discussed.

Ocular penetration of subconjunctival oxacillin, methicillin, and cefazolin in rabbits with staphylococcal endophthalmitis

The concentrations of oxacillin, methicillin, and cefazolin were examined in the infected eyes of pigmented rabbits with Staphylococcus aureus endophthalmitis after a subconjunctival dose of 100 mg. The three drugs had fairly similar ocular pharmacokinetics. The tissue concentration usually peaked within 30 min. Levels in the aqueous humor rose more slowly; the respective maximal concentrations of methicillin, oxacillin, and cefazolin were 72, 1,180, and 111 micrograms/ml. Oxacillin also produced the highest levels in the cornea. Penetration of the vitreous humor was poor with all three drugs, apparently owing to a diffusional barrier in the choroid-retina tissue complex. The respective median vitreous levels of methicillin, oxacillin, and cefazolin were 0.7, 0.6, and less than 0.8 micrograms/ml. These values are close to the concentrations usually required to inhibit S. aureus in vitro. Our results suggest that subconjunctival oxacillin achieves higher concentrations in anterior ocular tissues than do the other two drugs, but more aggressive approaches are necessary in treating endophthalmitis.

[Antibiotic concentrations in wound secretions and bone during the simultaneous administration of mezlocillin and oxacillin]

Mezlocillin and oxacillin have been used in combination for short-term antibiotic prophylaxis in orthopedic surgery. Antibiotic concentrations were measured in serum, wound secretions from subcutaneous tubings and bone. Half an hour after the i. v. application of 4 g mezlocillin + 2 g oxacillin, the concentrations in wound secretions were 20% of the serum levels. After four hours the levels of both antibiotics in wound secretions increased to 2.66 times the serum levels of mezlocillin, and 5.37 times those of oxacillin. After eight hours the concentrations in wound secretions dropped to about one half, but remained well within therapeutic levels. The parallel course of the concentrations of both antibiotics in wound secretions indicates that mezlocillin and oxacillin have very similar half-lives in wound secretions, although the serum half-lives (t 50% beta) of the two antibiotics are different. The concentrations obtained from cancellous bone were approximately. 10% of the serum levels one to two hours after the antibiotic infusion.

Desensitization of patients allergic to penicillin using orally administered beta-lactam antibiotics

When patients allergic to penicillin develop life-endangering infections that require treatment with beta-lactam antibiotics, they face a fatal infection or the possibility of a fatal allergic reaction. We have approached this situation by using an oral desensitization procedure before full-dose antibiotic therapy. Thirty consecutive patients with histories of allergic reactions to penicillin, positive immediate wheal and flare skin-test reactions to penicillin determinants, and life-threatening infections were studied. Bacterial endocarditis requiring penicillin G therapy led to desensitization of 19 patients, Pseudomonas sepsis of pneumonia requiring treatment led to desensitization of nine subjects, and staphylococcal infections requiring therapy with a penicillinase-resistant penicillin led to desensitization of two patients. Penicillin G or carbenicillin were administered orally, beginning with 100 U or 60 microgram, respectively. At 15-min intervals, progressively doubled doses were given during continuous monitoring for the appearance of allergic reactions. Within 5 hr, full therapeutic doses were administered intravenously. Skin-test reactions disappeared or diminished in all 23 subjects who were retested after desensitization. Full courses of antibiotic therapy and cure of the infections were accomplished in 30 of 30 patients. No deaths, anaphylaxis, or severe acute allergic reactions occurred. Pruritic cutaneous eruptions appeared in nine patients (30%) 6 to 48 hr after the onset of therapy. One patient developed reversible nephritis 3 wk into therapy with penicillin G. The results of this study suggest that oral desensitization is an effective, relatively safe approach to administering beta-lactam antibiotics to penicillin-allergic patients with life-threatening infections.

Sodium oxacillin in the horse: serum, synovial fluid, peritoneal fluid, and urine concentrations after single-dose intramuscular administration

Six healthy adult mares were given a single dose (25 mg/kg of body weight) of sodium oxacillin IM. Oxacillin concentrations in serum, synovial fluid, peritoneal fluid, and urine were measured serially over a 48-hour period. The mean peak serum oxacillin concentration was 9.75 microgram/ml at 0.5 hour after injection. Mean peak oxacillin concentrations in synovial and peritoneal fluids were 1.45 microgram/ml and 2.60 microgram/ml at 1 hour and 2 hours, respectively. These concentrations decreased in parallel with serum values and were not measurable at 48 hours. Urine concentrations of oxacillin were high, with a mean peak concentration of 2,790.2 microgram/ml at 0.5 hour.

[Studies reagarding the bioavailability of oxacillin from preconditioned powders]

Previous studies have pointed out a good antimicrobial activity of two oxacillin salts--DBED--oxacillin and calcic oxacillin--which were conditioned as "preconditioned powders" for oral suspensions. The above mentioned preparations were followed up by administration to animals, and similar seric concentrations in DBED oxacillin and sodic oxacillin (with the difference that insoluble salts present a long-time activity) were pointed out.

[External ventricular drainage: a possible method of treating cerebrospinal shunt infections and ventriculitis (author's transl)]

Infectious complications of hydrocephalus shunts are serious problems. A possible method of treating such infections is by external ventricular drainage (EVD). 20 patients - 17 with infected shunts, 3 with neonatal meningitis, ventriculitis and subsequent hydrocephalus - were treated by EVD and the results are presented in this report. The advantages of the procedure are control of the intraventricular pressure to bring it within normal limits and the possibility of intraventricular antibiotic instillation to supplement systemic therapy. Furthermore, the optimal operation time for the definitive shunt can be assessed by EVD once the infection has been overcome.

[Effect of administration of ampiox and guanosine triphosphate on the concentration of cyclic nucleotides in the muscle tissue of a zone of inflammation]

Experiments on rabbits with infiltrates induced by intracutaneous injection of staphylococcal culture were made to examine the content of cyclic nucleotides in the adjacent muscle tissue under the effect of administering ampiox alone or combined with guanosine triphosphate (GTP). Combined injection of ampiox and GTP to the infected animals produced a considerable elevation in the content of cAMP (more than 2 1/2-fold) and in the cAMP/cGMP ratio along with a beneficial therapeutic effect. The possible mechanisms of action of the agents administered are discussed.