Gastrointestinal side effects of clindamycin and ampicillin therapy

Hospitalized patients who received clindamycin or ampicillin were evaluated for gastrointestinal side effects for a period of up to six weeks after therapy was discontinued. Of 104 patients receiving clindamycin therapy, 31 (29.8%) developed diarrhea, and two (1.9%) developed pseudomembranous colitis (PMC). Of 138 patients receiving ampicillin, 24 (17.3%) developed diarrhea, and one (0.7%) developed PMC. Diarrhea persisting for three days or more was noted in 13 (12.5%) of the patients receiving clindamycin and in seven (5.1%) of those receiving ampicillin. The tendency to develop diarrhea was positively correlated with serious illness, abdominal or pelvic sepsis, and total dosage of clindamycin. Examination of stools from a patient with PMC that was associated with clindamycin therapy showed a decrease in the number of anaerobic bacteria from the numbers found in stool cultures of normal controls. Those patients who did not develop diarrhea also had fewer anaerobic bacteria and coliform organisms. Lymphocytes from the patient with PMC were hyporeactive to phytohemagglutinin and hyperreactive to clindamycin.

Aanerobic isolates in hemovac lines

Seventeen of 68 patients (25 percent) who required the use of hemovac drainage system after major head and neck procedures had positive anaerobic islates. Co-isolation of aerobic (94 percent) and other anaerobic (29 percent) microorganisms are common. There was an increased rate of psoitive anaerobic islates with procedures requiring exposure of mucosa. Radiotherapy, except in doses greater than 6,800 rads, did not affect the culture rate. Eight of 17 patients (47 percent) with positive anaerobic isolates had infectious-related complications while five of 51 patients (10 percent) with negative cultures had similar complications. Positive anaerobic isolates in hemovac lines can be correlated with pathogens isolated from subsequent complications.

Anaerobic infections

The treatment of anaerobic infection will be improved by: (1) having a high index of suspicion of anaerobic bacteria in all infections, (2) recognition of clinical signs characteristic of some of these infections, and (3) institution of antibiotics that are likely to be appropriate before the culture results become available 4 to 7 days later.

Quantitative nitro blue tetrazolium test in febrile patients. Correlation with diagnosis and bacterial activity of leukocytes

The quantitative nitro blue tetrazolium (NBT) test did not show increased NBT reduction in bacterial infections as frequently as has been reported with the qualitative NBT test in untreated infections. Lower than normal values were seen in septic shock and bacterial endocarditis, and normal results were seen in most other bacterial infections. Increased NBT reduction was seen with reticulum cell sarcoma, Hodgkin disease, postoperative wound infections, and upper respiratory tract infections. Thus, the quantitative NBT was of little use in diagnosis of acute infections. The correlation between quantitative tests and tests of bactericidal capacity of leukocytes was poor. These data suggest that NBT reduction and bactericidal activity are dissociative events within phagocytes. Patients with low NBT results usually had bactericidal activity within normal limits.

Therapy of Pseudomonas aeruginosa infections with tobramycin

The efficacy of tobramycin in doses of 2.7 to 5.6 mg/kg per day in 29 courses of therapy in 25 hospitalized patients with serious Pseudomonas aeruginosa infections was studied. Eighty-three percent of the P. aeruginosa strains showed zones of inhibition of 16 mm or more around a 10-mug tobramycin disk in the Bauer-Kirby disk method. Tobramycin minimal inhibitory concentration ranged from <0.05 to 1.5 mug/ml (microtiter twofold dilution method); for gentamicin they ranged from 0.05 to 6.2 mug/ml; corresponding geometric means were 0.19 and 0.49 mug/ml. Therapy was given for a median of 10 days (mean 19, range 1 to 83). The clinically satisfactory response rate for the 29 courses of therapy was 52%: critically ill, 44%; seriously ill, 50%; moderately ill, 80%. The response rates for various sites of infection were bone and cartilage, 100%; urinary tract infection, 56%; wound, 50%; respiratory tract, 67%; septicemia, 40%; abscess, 0%; burns, 44%. No adverse reactions were seen. Serum concentration (mug/ml +/- standard deviation) of tobramycin determined by an agar-well plate method, were 4.81 +/- 2.17 (1 h); 3.24 +/- 1.43 (2 h); 2.35 +/- 1.30 (4 h); and 1.40 +/- 1.09 (8 h). Tobramycin appears to be as effacacious as gentamicin in the treatment of serious P. aeruginosa infections and has a theoretical advantage of lower minimal inhibitory concentration for P. aeruginosa. The data suggest that, for life-threatening infections, dosages of tobramycin may need to be increased over those used in this study.

Neisseria meningitidis: a cause of nosocomial pneumonia

A 24-year-old man developed coma and many neurologic abnormalities for 2 weeks after ingesting phencyclidine. On admission, pulmonary aspiration occurred, for which he was given large doses of methylprednisolone, clindamycin, and gentamicin. These antimicrobial drugs were continued for 2 weeks until new pulmonary infiltrates were recognized. Neisseria meningitidis was subsequently isolated from cultures of conjunctival discharge, sputum, and blood and found to be resistant to clindamycin and gentamicin. N. meningitidis as a cause of nosocomial pneumonia in the setting of broad spectrum antimicrobial drugs is discussed.