Antimicrobials therapy

Leopold and Scheie (16,17) first introduced intravitreal antimicrobial therapy for treatment of endophthalmitis shortly after the development of antibiotics, but intraocular antibiotics did not gain favor for treatment of endophthalmitis for several decades. Up until the 1970s intravenous antimicrobials, frequent topical drops, and subconjunctival injections were the favored routes of antimicrobial delivery. Intravenous antimicrobial treatment was demonstrated to be effective in some cases of Staphylococcus epidermidis endophthalmitis, but effectiveness of intravenous therapy has not been demonstrated in randomized clinical trials (18). 

In the late 1970s and early 1980s, Peyman and Baum et al. (19,20) popularized the use of intraocular antibiotics and this route of administration became the mainstay of therapy for intraocular infection. Intraocular antimicrobials are now given in essentially all cases of endophthalmitis some patients are also treated with vitrectomy. In the EYS, all patients received intraocular antibiotics but only half the patients received systemic therapy. Systemic antimicrobials did not improve prognosis in the EYS, but amikacin, which has poor intraocular penetration, was used for gram-positive coverage in the study (1). 

In the EVS, a second culture was positive in eyes infected initially with gram-positive, coagulase-negative micrococci (20%), Staphylococcus aureus and Streptococcus (47%), and gram-negative organisms (62%) (1,43). Shaarawy et al. (44) also demonstrated persistent infection from a variety of organisms after appropriate intravitreal antimicrobials were injected. 

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The preparation of isothiazolidin-3-one 5-oxide and 5,5-dioxide derivatives of azetidin-3-ones was described (99EUP100069), starting from penicillanic acid sulfoxide amides in the presence of halogenating agents in anhydrous inert solvents or even without them. Through rearrangement and oxidation with conventional methods, compounds 73 could be obtained. For some derivatives the usefulness, as intermediates for the preparation of novel p-lactam analogs or active substances in formulations for antimicrobial therapy, is claimed. 

Lopez-Berestein, G. (1988). Liposomal amphotericin B in antimicrobial therapy, in Liposomes as Drug Carriers Recent Trends and Progress (G. Gregoriadis, ed.), John Wiley and Sons, Chichester, pp, 345-352. 

Stream-line antimicrobial therapy based on clinical judgment, patient response, and microbiological data... 

Antimicrobials therapy if increased sputum volume or change in color... 

Culture if keratitis is severe or sight-threatening. Otherwise, cultures or smears are used only if the corneal infiltrate is chronic or unresponsive to broad-spectrum antimicrobial therapy.19... 

Recognize that antimicrobial resistance is an inevitable consequence of antimicrobial therapy. 

Evaluate and apply at least six major drug-specific considerations when selecting antimicrobial therapy. 

Select empirical antimicrobial therapy based on spectrum-of-activity considerations that provide a measured response proportional to the severity of illness. Provide a rationale for why a measured response in antimicrobial selection is appropriate. 

Identify and apply five major principles of patient education and monitoring response to antimicrobial therapy. 

Only bacteria that cause disease should be targeted with antimicrobial therapy, and colonizing flora should be left intact whenever possible. 

Bacterial cultures should be obtained prior to antimicrobial therapy in patients with a systemic inflammatory response, risk factors for antimicrobial resistance, or infections where diagnosis or antimicrobial susceptibility is uncertain. 

Patient education, deescalation of antimicrobial therapy based on culture results, monitoring for clinical response and... 

Many areas of the human body are colonized with bacteria— this is known as normal flora. Infections often arise from one s own normal flora (also called an endogenous infection). Endogenous infection may occur when there are alterations in the normal flora (e.g., recent antimicrobial use may allow for overgrowth of other normal flora) or disruption of host defenses (e.g., a break or entry in the skin). Knowing what organisms reside where can help to guide empirical antimicrobial therapy (Fig. 66-1). In addition, it is beneficial to know what anatomic sites are normally sterile. These include the cerebrospinal fluid, blood, and urine. 

While selection of antimicrobial therapy may be a major consideration in treating infectious diseases, it may not be the only therapeutic intervention. Other important therapies may include adequate hydration, ventilatory support, and other supportive medications. In addition, antimicrobials are unlikely to be effective if the process or source that leads to the infection is not controlled. Source control refers to this process and may involve removal of prosthetic materials such as catheters and infected tissue or drainage of an abscess. Source-control considerations should be a fundamental component of any infectious diseases treatment. It is also important to recognize that there may be many different antimicrobial regimens that may cure the patient. While the following therapy sections... 

Most initial antimicrobial therapy is empirical because cultures usually have not had sufficient time to identify a pathogen. Empirical therapy should be based on patient- and antimicrobial-specific factors such as the anatomic location of the infection, the likely pathogens associated with the presentation, the potential for adverse effects in a given patient, and the antimicrobial spectrum of activity. Prompt initiation of appropriate therapy is paramount in hospitalized patients who are critically ill. Patients who receive initial antimicrobial therapy that provides coverage against the causative pathogen survive at twice the rate of patients who do not receive adequate therapy initially.8... 

Patients with a history of recent antimicrobial use may have altered normal flora or harbor resistant organisms. If a patient develops a new infection while on therapy, fails therapy, or has received antimicrobials recently, it is prudent to prescribe a different class of antimicrobial because resistance is likely. Previous hospitalization or health care utilization (e.g., residing in a nursing home, hemodialysis, and outpatient antimicrobial therapy) are risk factors for the acquisition of nosocomial pathogens, which are often resistant organisms. 

Renal and/or hepatic function should be considered in every patient prior to initiation of antimicrobial therapy. In general, most antimicrobials undergo renal elimination and... 

The patient was admitted to the hospital with a presumptive diagnosis of health care-associated pneumonia (based on the recent hospitalization). He received intravenous hydration with normal saline, 5 L oxygen via face mask, an insulin infusion to control his glucose, and empirical antimicrobial therapy with piperacillin-tazobactam 2.25 g intravenously every 6 hours and vancomycin 1 g intravenously every 24 hours. All other medications are continued with the exception of the diabetes medications. 

Should antimicrobial therapy be modified based on the culture results ... 

Can the antimicrobial therapy be converted from intravenous to oral therapy ... 

After selection and initiation of antimicrobial regimen, there are a number of additional patient care and monitoring considerations that should be addressed to improve the likelihood of a successful outcome. Patient education, deescalation of antimicrobial therapy based on culture results, monitoring for clinical response and adverse effects, and appropriate duration of therapy are important. 

Antimicrobial spectra. In Gilbert DN, Moellering RC, Eliopoulos GM, Sande MA, eds. The Sanford Guide to Antimicrobial Therapy 2005.35th ed. Hyde Park, VT Antimicrobial, Inc. 2005. 

Baddour LM, Wilson WR, Bayer AS, et al. Infective endocarditis Diagnosis, antimicrobial therapy, and management of complications a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association endorsed by the Infectious Diseases Society of America. Circulation 2005 111(23) 394M34. 

Ideally, lumbar puncture to obtain cerebrospinal fluid (CSF) for direct examination and laboratory analysis, as well as blood cultures and other relevant cultures, should be obtained before initiation of antimicrobial therapy. However, initiation of antimicrobial therapy should not be delayed if a pretreatment lumbar puncture cannot be performed. 

Prompt initiation of intravenous high-dose cidal antimicrobial therapy directed at the most likely pathogen (s) is essential due to the high morbidity and mortality associated with CNS infections parenteral (intravenous) therapy is administered for the full course of therapy for CNS infections to ensure adequate CSF penetration throughout the course of treatment. 

Empirical antimicrobial therapy should be modified on the basis of laboratory data and clinical response. 

Components of a monitoring plan to assess the efficacy and safety of antimicrobial therapy of CNS infections include clinical signs and symptoms and laboratory data (such as CSF findings, culture, and sensitivity data). 

A high index of suspicion should be maintained for patients at risk for CNS infections. Prompt recognition and diagnosis are essential so that antimicrobial therapy can be initiated as quickly as possible. A medical history (including risk factors for infection and history of possible recent exposures) and... 

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