Contact allergy following administration of eyedrops and eye ointments

Thirty-five ophthalmological patients with symptoms of contact allergy due to external eye medication were examined with patch tests in the dermatological outpatient department. Attention is paid to sensitization due to antibiotics, in particular Neomycin.

[Nebacetin and taurolin as intraoperative disinfectant solutions in surgery of the locomotor system (author's transl)]

The anti-infective preventive action of intraoperative disinfection with physiological solution containing antibiotics, appears to be firmly established, judging from numerous publications. Since germs are showing a world-wide increasing resistance, the search for antibiotics which continue to be effective must be kept up, but alternative suggestions are equally necessary. Some publications have already been presented indicating that success similar to that previously obtained with antibiotics is possible by using disinfectants in the prophylaxis and treatment of infections. Hence, a comparative study was conducted using the non-absorbable broad-spectrum antibiotic Nebacetin and the disinfectant Taurolin in a 1% solution with a group of patients subjected to a total of 7699 major and minor surgical operations. Prospectively, early infections during the stay of the patient in the hospital, als well as disturbed wound healing, were included. No significant difference was found in the number of infections and the rate of disturbed wound healing. Indirectly, it is possible to conclude with the help of results from literature that the disinfectant Taurolin is suitable as an addition to intra-operative rinsing in the prophylaxis of infections.

Single-dose parenteral antibiotics as prophylaxis against wound infections in colonic operations

A study of 77 patients undergoing elective operations on the colon and rectum, where wounds were subject to contamination by fecal flora, did not demonstrate that the addition of a preoperative oral regime to parenteral antibiotics alone further decreased the incidence of wound infection. The authors feel that the use of single-dose clindamycin and cephazolin intravenously preoperatively has been shown to be a very effective method of preventing wound infection in elective colonic resections.

Management of hot tar burns

Burns due to hot tar present a difficult management problem because the tar is difficult to remove without inflicting further injury to the underlying burn. We have found the surface active agent polyoxyethylene sorbitan (Tween 80, Sigma, St. Louis, MO) or Polysorbate (Sigma), by itself or in combination with an antibiotic ointment (neomycin sulfate) to be a safe and effective means of tar removal.

[Orthograde intestinal irrigation as a preoperative intestinal preparation. Reduction of the intestinal flora using antibiotics]

Whole gut irrigation is a now a well-established method of preoperative bowel preparation. Additional reduction of bacterial content is desirable. The influence of neomycin/bacitracin and clindamycin as well as the combination, as admixture to the whole gut irrigation, on the flora of the large intestine, was therefore investigated in a prospective controlled study. While neomycin/bacitracin caused only a reduction of aerobic, and clindamycin of the anaerobic bacteriae, the combination resulted in a nearly total eradication of detectable bacterial content at the time of operation.

Wound healing. The effects of topical antimicrobial agents

The effect of four commonly used topical antimicrobial agents on the rate of reepithelialization of clean wounds was evaluated in white domestic pigs. Neosporin Ointment was found to significantly increase the rate of reepithelialization by 25%, while Furacin significantly retarded the healing rate by 24%. Pharmadine, a preparation containing povidone-iodine, did not affect the rate of healing. Both Silvadene and its vehicle significantly increased the rate of reepithelialization by 28% and 21%, respectively. The effects of these agents cannot be explained on the basis of their antimicrobial activity.

Influence of oral antibiotics on resistance and enterotoxigenicity of Escherichia coli

Three groups of five piglets were formed and 1390 Escherichia coli isolates were obtained during the 45-day period of observation. One of the groups received feed without antibiotic whereas the second received feed containing 100 ppm neomycin and the third feed with 100 ppm neomycin plus 100 ppm tetracycline. Rectal swabbings for bacterial isolation were repeated ten times, twice during an adaptation period and eight times during the treatment period. Resistance among the isolates to tetracycline, streptomycin and triple sulfas remained high throughout this experiment whereas resistance to neomycin, chloramphenicol and ampicillin were found to increase significantly under the influence of antibiotic supplemented feed. This increase of antibiotic resistance was associated with an increase of the percentage of isolates harboring an R. factor. When comparing the ability of strains harboring an R factor to receive the plasmid Ent from the E. coli K12 (P155) with isolates not harboring such a plasmid, no significant difference was observed in their ability to receive the Ent plasmid.

Controlled clinical trial comparing intra-incisional cephaloridine and Polybactrin Spray

300 patients undergoing various operations were randomly allocated to receive, intra-incisionally, just before skin suture, either a solution of 1 g cephaloridine or Polybactrin aerosol. An equal number of patients were allocated to each group, and various factors likely to influence the incidence of wound infections were evenly distributed. 13 wound infections (9.8%) developed in the cephaloridine group and 28 (20.1%) in the Polybactrin group (p less than 0.02). In the former group, the infections were milder and there were 44 fewer patient-days of hospitalisation. The difference in infection rates for 'potentially contaminated and contaminated' operations was greater (p less than 0.01), in favour of cephaloridine. Other differences are discussed and some reasons for the superiority of cephaloridine over other agents (e.g., povidone-iodine, ampicillin) are advanced.

Neomycin absorption following Clagett procedure for postpneumonectomy empyema

Following a Clagett stage II procedure, significant amounts of neomycin are absorbed when concentrations of 0.25% neomycin (8.9 micrograms milliliter) are used. If higher concentrations are employed, the neomycin can achieve toxic levels (40 micrograms per milliliter), with associated renal toxicity and respiratory suppression. The peel of the empyema cavity does not prevent absorption of drugs. Therefore, when drugs are inserted into an empyema cavity, due care must be exerted to prevent drug toxicity.

Neomycin and the combination of neomycin and bacitracin in the prevention of bacterial infection in surgery of the colon and/or rectum

In two groups of patients submitted to surgery of the colon and/or rectum, treatment to prevent bacterial infections using a combination of 100 mg neomycin and 10,000 U bacitracin every 6 h for 48 h gave the same results as neomycin employed alone at a dosage of 500 mg every 6 h for 48 h. Results confirm the synergism of action between neomycin and bacitracin.

Wound healing. The effects of topical antimicrobial agents

The effect of four commonly used topical antimicrobial agents on the rate of reepithelialization of clean wounds was evaluated in white domestic pigs. Neosporin Ointment was found to significantly increase the rate of reepithelialization by 25%, while Furacin significantly retarded the healing rate by 24%. Pharmadine, a preparation containing povidone-iodine, did not affect the rate of healing. Both Silvadene and its vehicle significantly increased the rate of reepithelialization by 28% and 21%, respectively. The effects of these agents cannot be explained on the basis of their antimicrobial activity.

The penetration of gentamicin and neomycin into perilymph across the round window membrane

Many commonly employed otic drops contain aminoglycoside antibiotics that may be toxic to the inner ear. A variety of chemicals such as ionic solutions, certain anesthetics, and epinephrine have been shown to diffuse across the round window membrane into the perilymph. Twelve adult cats were studied in this experiment. The auditory bulla was exposed and solutions containing gentamicin or neomycin concentrations similar to that commonly used in otic drops were applied to the round window niche for 15 minutes and washed with saline solution. The gentamicin and neomycin concentrations in the round window niche wash and the perilymph were then assayed by a radioenzymatic method. Concentrations of both antibiotics were observed in the perilymph. Thus, the round window membrane is a route through which these ototoxins may gain access to the inner ear.

Effects of neomycin alone and in combination with cholestyramine on serum cholesterol and fecal steroids in hypercholesterolemic subjects

Effects of neomycin were studied on serum cholesterol and fecal steroids in hypercholesterolemic patients during a short treatment period (4 wk) and a long treatment period (16 mo), using small (1.5 g/d) and large (up to 6 g/d) doses alone and in combination with cholestyramine. In the short-term low-dose study the decrease in serum cholesterol by 21% was associated with a proportionate increase in fecal cholesterol elimination as neutral sterols through impaired cholesterol absorption. Serum cholesterol remained low and fecal steroid excretion remained elevated in the long-term neomycin study. Increasing the dosage from 1.5 to 6 g/d at the end of the 16-mo period brought about a further slight decrease in serum cholesterol and a small further increase in fecal neutral and acidic steroids. The increases in fecal bile acids and fat but not in neutral sterols were positively correlated with the increases in the neomycin dosage. Thus, large neomycin doses can also cause bile acid malabsorption. In another series of patients, a decrease (25%) in serum cholesterol by cholestyramine was associated with a proportional increase in the fecal elimination of cholesterol (2.5-fold) as bile acids. The inclusion of neomycin in cholestyramine therapy further increased fecal steroid output (solely as neutral sterols) by only about one-fifth of that due to cholestyramine, but further decreased serum cholesterol almost to the same extent (-17%) as cholestyramine alone. The overall decrease was 38%, no side effects occurred, and the patients found combination therapy convenient. Neomycin decreased serum cholesterol in different studies by 10+/-2, 17+/-4, and 12+/-4% per 100 mg/d of the increment in fecal steroids, the respective decrease for cholestyramine being only 2.2+/-0.5%. Thus, neomycin effectively reduced serum cholesterol by a relatively small increase in cholesterol elimination (via cholesterol malabsorption) compared with cholestyramine-induced bile acid malabsorption.

Oral neomycin dosage schedules for suppression of ammonia production by bowel flora

To better define a minimal but optimal dose of oral neomycin to suppress ammonia production by bowel flora, several dosage regimens were examined in normal healthy volunteers. Fecal urease activity was quantitatively determined and was used as an indirect measure of intrinsic ammonia production by bowel flora. Large doses of neomycin were found to exert inhibition of fecal urease for many days. There was considerable variation in enzymatic activity among subjects even after adjustments were made for protein content of the stool. Depending on the dose, there was a 1- to 3-day lag in neomycin effect on stool urease activity and several days of continued effect. The most effective regimen of those studied was a loading dose of 6 g of neomycin given in three divided doses on day 1, followed by 1 g twice daily.

Treatment of fulminant viral hepatitis with anti-lymphocyte gamma globulins

Ten patients affected by fulminant viral hepatitis (F.V.H.) were treated with anti-lymphocyte globulins (A.L.G.) besides peritoneal dialysis (P.D.) and exchange blood transfusion (E.T.). Two patients awoke transiently; six recovered from F.V.H., but two of them died afterwards due to later complications. The total of complete recovery was 40%; this result is compared with those previously obtained by the Authors in 38 patients treated only with P.D. and E.T. (28.9% complete recovery), and in seven patients treated with P.D., E.T. and human anti-HBsAg gamma globulins (28.5% complete recovery). The treatment with A.L.G. was performed because of the discouraging results until now obtained with the various liver support systems and is based on the accepted view that lymphocytes might be the true effectors of cell necrosis in F.V.H.

The effect of topical application of antibiotics on the cerebral cortex: an experimental update

✓ A common complication of intrathecal sepsis is the development of clinical seizure activity. However, some of the newer, commonly used antibiotics may have epileptogenic and electrocortical depressant effects when applied topically to the cerebral cortex. Epileptogenic characteristics of these antibiotics may be masked by the known tendency for intracranial sepsis to produce both early and late clinical seizure problems. In this experimental study, electrocortical spike activity was produced by penicillin, methicillin, cephalothin, carbenicillin, colistimethate, and neomycin, and electrocortical depression was caused by tobramycin and gentamicin. A mixed picture was found with neomycin and carbenicillin.

Endophthalmitis associated with Haemophilus influenzae type b bacteremia and meningitis

The unusual occurrence of endophthalmitis associated with Haemophilus influenzae type b bacteremia and meningitis was confirmed in three young children during a five-year period. In contrast to bacterial endophthalmitis attributed to other microorganisms, these three infections resolved completely within a few days with conventional antimicrobial therapy. Endophthalmitis is but one of the apparently increasing number of unsuual complications that may be observed as a result of H influenzae type b bacteremia.

Nephrotoxicity and ototoxicity following irrigation of wounds with neomycin

Renal failure and ototoxicity developed in two patients following wound irrigation with neomycin. In both patients the renal failure was reversible, but the deafness was progressive despite withdrawal of the neomycin. In one patient the serum neomycin concentration was still markedly elevated (42 microgram/ml) 2 days after use of the drug was discontinued. The authors suggest that irrigation of large open wounds with neomycin is dangerous since toxic blood concentrations may ensue. The benefits conferred by neomycin irrigation should be weighed against the possible danger of permanently impaired hearing.

The therapy of otitis externa

The clinical findings following the instillation of an aqueous solution containing natamycin, neomycin and hydrocortisone into the ears of dogs exhibiting the signs of otitis externa are described. Out of a total of 143 cases, 50 were also examined microbiologically both before and after treatment in order to evaluate the antibacterial and antifungal properties of the solution. The severity of the complaint appeared to be of little significance as far as the respons is concerned. A favourable response was noted clinically in 95% and microbiologically in 86% of the cases treated.