<prompt> Which of the following drugs is active against Pseudomonas?CeftriaxonePiperacillin-tazobactumAmpicillinCefalexin  <response>: SEMISYNTHETIC PENICILLINS: CLASS I FI CATION 1 . Acid-resistant alternative to penicillin G Phenoxymethyl penicillin Penicillin V. 2. Penicillinase-resistant penicillins Methicillin, Cloxacillin. 3. Extended spectrum penicillins a Aminopenicillins: Ampicillin, Bacampicillin, Amoxicillin. b Carboxypenicillins: Carbenicillin, Ticarcillin. c Ureidopenicillins: Piperacillin, Mezlocillin. Beta lactamase inhibitors: Clavulanic acid Sulbactam, Tazobactam Piperacillin: This antipseudomonal penicillin is about 8 times more active than carbenicillin. It has good activity against Klebsiella and is used mainly in neutropenic immunocompromised patients having serious gram-negative infections, and in burns. Elimination tlh is 1 hr. Concurrent use of gentamicin or tobramycin is advised. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:699,702 