Current use of antibiotics in opthalmology

The use of antibiotics in opthmalmology is based on the information from sensitivity studies derived from the ocular microbiology laboratory and results of clinical studies. Because of systemic use of antibiotics, bacteria develop mechanisms of resistance over time. The organisms considered pathogens evolve to become less frequent, and unusual organisms become the primary culprit. We have found an increasing trend of gram positive organisms such as Staphylococci and a decreasing incidence of gram negatives. As the same time, the antibiotic sensitivity profile has changed. The fluoroquinolones have been the antibiotic of choice for the last decade. Current laboratory data show a decreasing sensitivity profile. Clinical data are beginning to emerge that mirror this information. Data show that aminoglycosides, penicillins and other antibiotics such as vancomycin and chloramphenicol may be more appropriate. New antibiotics such as the oxazliodones and new generation quinolones may soon become the antibiotics of choice. (AU)

Considerations for implementing an antibiotic policy in hospital practice

An antibiotic policy should aim for the safe, effective and economical use of antimicrobial drugs, and to prevent their indiscriminate use and development of resistant bacterial strains. The term 'antibiotic' is used as a general term for all antimicrobial drugs. Antibiotics prescriptions should be based on clinical evidence of bacterial infection, preferably substantiated by appropriate laboratory culture and sensitivity tests. Viral infections are not an indication for antibiotic prescriptions. Patient factors to be considered for choice and dose of an antibiotic are age, pregnancy, lactation, renal and hepatic impairment. Immunodeficient patients should receive only bactericidal drugs. Severity of infection determines the route of administration. Duration of therapy should not exceed five days, unless specifically prescribed by the physician. An antibiotic should, if started as an empirical therapy not be changed before a minimum of three days trial. Prescriptions of drugs such as aztreonam, imipenem, vancomycin, piperacillin and amphotericin are to be restricted due to cost and toxicity and should be reviewed by the microbiologist (AU)

Metronidazole: a review

Metronidazole (Flagyl) is a 5-nitroimidazole extensively used in many countries in the treatment of several protozoan infections (trichomoniasis, giardiasis, amoebiasis) and obligate anaerobic infections. It is well tolerated orally and parentally with minimal untoward effects. Metronidazole is rapidly replacing clindamycin in many countries, as resistance to clindamycin has been reported. Metronidazole crosses the blood-brain barrier readily, diffuses well into pus and is therefore very effective in the treatment of brain abscess due to anaerobes. In combination with an aminoglycoside, metronidazole provides grood prophlaxis perioperatively in intra-abdominal surgery. Metronidazole is also useful in the management of other diseases such as pseudomembranous colitis and rosacea. Metronidazole is inexpensive when compared with other antibiotics used to treat anaerobic infections, (for example clindamycin). (Summary)

Aminoglycoside resistance in clinical isolates of gram-negative bacilli at the University Hospital of the West Indies

The pattern of aminoglycoside resistance in clinical isolates of gram-negative bacilli at the University Hospital of the West Indies, Jamaica, was studied. The levels of resistance were (1) kanamycin 50.4 percent, (2) gentamicin 6.7 percent, (3) tobramycin 5.9 percent and (4) amikacin 0.6 percent. There was considerable cross-resistance between gentamicin and tobramycin among strains of enterobacteriaceae. Tobramycin, however, was superior to gentamicin against isolates of Pseudomonas. Amikacin was the most active aminoglycoside and was effective against 99.4 percent of all isolates tested. Furthermore, it was effective against isolates resistant to one or more of the other amino-glycosides. Measures to prevent further increase in aminoglycoside resistance, especially in the judicious usage of these valuable agents and strict adherence to the principles of cross-infection control while dealing with patients infected or colonized with resistant strains, are discussed and emphasized (AU)