Antibiotic resistance combined drug therapy

TMP-SMX is also used in the treatment of infection caused by ampicillin-resistant Shigella spp. and for antibiotic-resistant Salmonella spp.. The combination is also effective for covering the carrier state of Salmonella typhi, the agent of typhoid fever, and other Salmonella spp.. Successful treatment of traveler s diarrhea due to susceptible E. coli is another advantage of the use of this combination. The combination is not indicated in the therapy of enterohemorrhagic E. coli strains such as 0157 H7 because of the risk of developing hemolytic-uremic syndrome associated with the release of the cytotoxic enterotoxin by the drugs. 

Imipenem-cilastatin is effective for a wide variety of infections, including urinary tract and lower respiratory infections intra-abdominal and gynecological infections and skin, soft tissue, bone, and joint infections. The drug combination appears to be especially useful for the treatment of infections caused by cephalosporin-resistant nosocomial bacteria, such as Citrobacter freundii and Enterobacter spp. It would be prudent to use imipenem for empirical treatment of serious infections in hospitalized patients who have recently received other P-lactam antibiotics because of the increased risk of infection with cephalosporin- and/or penicillin-resistant bacteria. Imipenem should not be used as monotherapy for infections owing to P. aeruginosa because of the risk of resistance developing during therapy. 

Tetracyclines, like doxycycline, are broad-spectrum antibiotics with extended use as cheap and effective antibacterials. They act at the level of protein synthesis, and impair, in case of Plasmodium fakiparum, the formation of mero-zoites. Due to a slow onset of activity, doxycycline is used in combination with faster acting drugs for malaria therapy as a single compound it is today applied in prophylaxis, frequently in regions with known chloroquine resistance. 

Erythromycin and clindamycin are the most common used topical antibiotics for the treatment of acne [14]. Topical antibiotics have a bacteriostatic and bactericidal effect, reducing P. acnes colonization of the sebaceous follicle. However, topical antibiotics have not to be used in monotherapy due to the high risk of increasing P. acnes resistance. The development of resistance is less frequent in patients who are treated with combination therapy (benzoyl peroxide/erythromycin benzoyl peroxide/clindamycin). These associations enhance the bactericidal effect, reducing the risk of drug-resistance. 

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