<prompt> Which of the following drug is not used against pseudomonas? UP 2005PiperacillinCarbenicillinTicarcillinOxacillin  <response>: Because community-associated methicillin-resistant Staphylococcus aureus CA-MRSA causes more than one half of all staphylococcal infections in most communities, empiric therapy with penicillins or cephalosporins may be inadequate. Some expes recommend combination therapy with a penicillinase-resistant penicillin or cephalosporin in case the organism is methicillin-sensitive S aureusand clindamycin or a quinolone. Others suggest use of clindamycin, trimethoprim-sulfamethoxazole TMP-SMX, rifampin, doxycycline, or a quinolone. Finally, because of concerns about induction of resistance, some recommend using TMP-SMX and rifampin in combination, rather than singly. As data accumulate, clindamycin may become the preferred outpatient antibiotic therapy compared with TMP-SMX in regions with a relatively low incidence of clindamycin resistance.Recently, treatment guidelines have been published. USES: Staphylococcal Infections Mild to moderate infections: 250-500 mg IVIM q4-6hr Severe infections: 1 g IVIM q4-6hr Acutechronic osteomyelitisstaphylococci infections: 1.5-2 g IV q4-6hr Renal Infection CrCl 10 mLmin: May consider adjusting to the lower range of the usually recommended dose depending on severity of infection REFERENCE: 