Antibiotic concentrations in relation to structural changes in maxillary sinus mucosa following intramuscular or peroral treatment

Demonstration of pathogenic bacteria in "sterile" inflammatory exudates

One hundred and twenty-seven exudates from inflammatory processes, judged sterile after incubation on standard isolation media, were further investigated. This involved the exclusion of slow-growing strains by a further 48 hours incubation of the primary plates and subcultures from hypertonic broth that had been inoculated concurrently with the initial cultures. Over 80% of otherwise sterile exudates grew presumptive pathogens only after passage through the hypertonic broth and no further isolations resulted from extended incubation of the primary cultures. A history of current, or recent, antibiotic therapy commonly accompanied the demonstration of these aberrant strains and clinical remission of symptoms usually followed fresh antibiotic therapy directed solely against the revertant isolates.

Distribution of lymecycline in interstitial fluid and paranasal sinus mucosa. An experimental and clinical study

A comparison between different methods of determining the levels of lymecycline in tissue is presented. The drug levels have been compared with those registered, during the steady state condition, in interstitial fluid obtained from subcutaneously implated tissue cages in rabbits. The 'tissue piece diffusion method' developed is reproducible; it allows antibiotic levels to be determined in minute pieces of tissues, and it seems to measure the total diffusable drug in the interstitial fluid phase. This method was employed in the analyses of lymecycline concentrations in the maxillary sinus mucosa in 12 patients, and it demonstrated a good penetration into the tissue. The level reached was well above the Minimal Inhibitory Concentration of most bacteria causing maxillary sinusitis.

The antibacterial effect of antibiotics in treatment of maxillary sinusitis

The antibacterial effect of antibiotic treatment in maxillary sinusitis has been assessed by studying the elimination of bacteria from the maxillary sinus during treatment with penicillin and tetracycline. As adequate antibiotic concentrations are the prerequisite for maximal antibacterial effect, the antibiotic concentrations were controlled. The antibiotic concentrations were determined in maxillary sinus secretions and/or mucosas of 113 patients with maxillary sinusitis, treated with single or repeated doses of penicillin or tetracycline, or the two antibiotics in combination. In 30 patients treated with either penicillin or tetracycline, the bacterial growth in sinus secretion was controlled before and after treatment. It was established that ordinary clinical doses of penicillin and tetracycline may, although not invariably, result in antibiotic concentrations in sinus secretion and sinus mucosa than can be regarded as adequate for treatment, i.e. for penicillin greater than or equal to 0.25 mug/ml and for tetracycline greater than or equal to 1.0 mug/ml. The necessity of achieving adequate antibiotic concentrations in sinus secretion and sinus mucosa to ensure therapeutic success was demonstrated. Thus, bacterial growth remained in the secretions of most maxillary sinuses when the concentrations of penicillin or tetracycline in the secretions were not regarded as adequate for treatment. In contrast, the bacteria were exterminated in most cases where concentrations were regarded as adequate.

Evaluation of the antibiotic effect of treatment of maxillary sinusitis

As the effect of antibiotic treatment of maxillary sinusitis has been questioned, the elimination of bacteria from sinus secretions was studied during antibiotic treatment. Penicillin V, azidocillin, tetracycline or doxycycline was administered to 54 patients with maxillary sinusitis. Samples of sinus secretion were aspirated both before treatment and 2-3 days after the onset of treatment. When the antibiotic concentration was below the upper limit of MIC for sensitivity group 1, bacterial growth was present in practically all samples. When the antibiotic concentration equalled or was above this limit, there was no bacterial growth in about half of the samples. A prerequisite for antibiotic effect--elimination of bacteria--is that the antibiotic concentration is well above the MIC of the bacteria at the site of infection. The choice between bactericidal or bacteriostatic antibiotics appeared unimportant. Bacterial survival in the maxillary sinus despite a high antibiotic concentration in the sinus illustrates that MIC values determined in the laboratory do not always mirror the sensitivity of bacteria to antibiotics in vivo.

Erythromycin stearate in acute maxillary sinusitis

76 patients with acute maxillary sinusitis were treated with oral erythromycin stearate (500 mg twice or 3 times a day for 10 days). The mean concentration of erythromycin in the sinus secretion after 3-5 days' treatment was 0.6 mug/ml with the lower dosage and 1.3 mug/ml with the higher. The concentration of erythromycin in the sinus secretion was, on the average, 10-20 times higher than the minimum inhibitory concentration (MIC) for group A streptococci and pneumococci, and reached MIC values for 15-30% of 100 examined strains of Haemophilus influenzae. 81% of the patients given the smaller and 94% of those given the larger dose improved or recovered. Radiological improvement was demonstrated in both groups. The infections with H. influenzae tended to respond somewhat less to the treatment than those with pneumococci. Comparisons of the roentgen findings and the findings at aspiration showed good agreement. An extra projection taken with the patient recumbent and the affected side downwards gave no information above that obtained from the routine projections. The large dose caused side effects more often (in 17/41 patients) than the smaller one (4/35 patients). In 10 patients treatment was discontinued because of side effects; 8 of them had received the larger dose.