Penicillins piperacillin

It is formed by acylases that cleave off the side chain of the penicillins, and can also be obtained by the selective chemical cleavage of the amide, leaving the lactam intact. After this, 6-APA can be easily acylated by any carboxylic acid, and this has yielded literally thousands of semisynthetic penicillins in the past 30 years, many showing improved stability and activity. Some of them are lactamase resistant (methicillin (9.41), oxacillin (9.42) and its halogenated derivatives), whereas others are broad-spectrum antibiotics, like the orally active ampicillin (9.43), which also inhibits Gramnegative bacteria but is sensitive to lactamase. Carbenicillin (9.44) is particularly active against Pseudomonas and Proteus infections, which are unaffected by natural penicillins. Piperacillin (9.45), a broad-spectrum compound, is spectacularly active against Pseudomonas. 

Antipseudomonal penicillin piperacillin, piperacillin/tazobactam, ticarcillin/clavulanic acid. 

Clinically important, potentially hazardous interactions with amoxicillin, ampicillin, antacids, bacampicillin, calcium carbonate, carbenicillin, cloxacillin, digoxin, methotrexate, methoxyflurane, mezlocillin, nafcillin, oxacillin, penicillins, piperacillin, ticarcillin, zinc... 

Clinically important, potentially hazardous interactions with acitretin, aluminum hydroxide, amoxicillin, ampicillin, antacids, bacampicillin, betamethasone, bismuth, bromelain, calcium, carbenicillin, cholestyramine, doxacillin, corticosteroids, dairy products, dicloxacillin, didanosine, digoxin, food, glidazide, iron, isotretinoin, methicillin, methotrexate, methoxyflurane, mezlocillin, nafcillin, oxacillin, penicillins, piperacillin, retinoids, rocuronium, strontium ranelate, sucralfate, ticarcillin, vitamin A, zinc... 

At least four different types of empirical parenteral antibiotic regimens are in use (1) monotherapy with an antipseudomonal cephalosporin (cefepime or ceftazidime) or antipseudomonal car-bapenem (imipenem-cilastatin or meropenem), (2) combination therapy with an aminoglycoside plus an antipseudomonal penicillin (piperacillin-tazobactam or ticarciUin-clavulate), an antipseudomonal cephalosporin, or an antipseudomonal carbapenem, (3) vancomycin plus an antipseudomonal cephalosporin or antipseudomonal carbapenem, with or without an aminoglycoside, and (4) a fluoroquinolone (ciprofloxacin or levofloxacin) in combination with an... 

Noninterfering amikacin, apalcillin, carbenicillin, cefoperazone, clindamycin, eiythromy-cin, gentamicin, penicillin, piperacillin, ticarcillin, tobramycin, vancomycin... 

Piperacillin/tazobactam 3.375 g every 6 hours Avoid if allergic to penicillin... 

When used for intraabdominal infection, aminoglycosides should be combined with agents that are effective against the majority of B. fragilis. Clindamycin or metronidazole is the agent of first choice, but others, such as antianaerobic cephalosporins (e.g., cefoxitin, cefotetan, or ceftizoxime), piperacillin, mezlocillin, and combinations of extended-spectrum penicillins... 

The answer is b. (Hardman, pp 1077—1086.) Piperacillin is a broad-spectrum, semisynthetic penicillin for parenteral use. Its spectrum of activity includes various Gram-positive and Gram-negative organisms including Pseudomonas. The indications for piperacillin are similar to those for car-benicillin, ticarcillin, and mezlocillin, with the primary use being sus-... 

Monotherapy with imipenem 0.5 g IV every 6-8 hours, meropenem 1 g IV every 8 hours, ertapenem 1 g IV every 24 hours, extended-spectrum penicillins with a /3-lactamase inhibitor (piperacillin/tazobactam 4.5 g IV every 6 hours), or tigecycline 100 mg IV as loading dose, then 50 mg IV every 12 hours... 

Aninoglycosides Gentamicin Tobramycin Amikacin Penicillins Ampicillin Ampicillin-sulbactam Ticarcillin-davulanate Piperacillin-tazobactam Cephalosporins, first-, second-, and third-generation... 

Fourth generation Examples are piperacillin, azlocillin, and mezlocillin that kill all the bacterial strains covered by the third generation with higher potency. This generation of penicillins is also susceptible to fylactamases. 

Cystic fibrosis Cystic fibrosis patients have a higher incidence of side effects (eg, fever, rash) when treated with extended-spectrum penicillins (eg, piperacillin, carbenicillin). 

Children Safety and efficacy of carbenicillin, piperacillin, and the -lactamase inhibitor/penicillin combinations have not been established in infants and children younger than 12 years of age. Use caution in administering to newborns and evaluate organ system function frequently. 

Mezlocillin, piperacillin, and ticarcillin are parenteral antibiotics formulated as sodium salts, so prescribers must consider the sodium content of these antibiotics when administering them to patients with congestive heart failure. During their distribution phase, antipseudomonal penicillins achieve orfly low concentrations in the cerebrospinal fluid. Consequently, antipseudomonal penicillins are not among the drugs of first choice for meningitis therapy. 

The antipseudomonal penicillins undergo renal elimination (Table 45.1). Piperacillin and ticarcillin have minimal hepatic metabolism. In contrast, mezlocillin has significant hepatic metabolism and requires dose adjustment in patients with hepatic insufficiency. 

The antipseudomonal penicillins have comparable spectra of activity against many gram-positive and gram-negative pathogens, including most anaerobes. Mezlocillin, piperacillin, and ticarcillin have similar clinical outcomes in patients with known or suspected P. aeruginosa infections. Antipseudomonal penicillins are used to treat pneumonias associated with cystic fibrosis or mechanical ventilation. 

Rx amoxicillin, ampicillin, bacampicillin, carbenicillin, cloxacillin, dicloxacillin, flucloxacillin, methicillin, mezlocillin, nafcillin, oxacillin, penicillin G benzathine, penicillin G potassium, penicillin Vpotassium, piperacillin, pivampicillin, pivme-cillinam, ticarcillin Penicillin and beta-lactamase inhibitors amoxicillin/ clavulanate potassium, ampicillin/sulbactam sodium, piperacillin sodium/ tazobactam sodium, ticarcillin disodium/clavulanate potassium Chemical Class Penicillin, natural... 

In the treatment of infections caused by E aeruginosa, the antimicrobial agent that has proved to be effective is Penicillin G Piperacillin Nafcillin Erythromycin Tetracycline... 

Penicillins (bactericidal inhibit cell wall crosslinking) e.g., benzylpenicillin, phenoyxmethylpenicillin, ampicillin, amoxicillin, flu-cloxacillin, methicillin, piperacillin Cephalosporins (bactericidal inhibit cell wall crosslinking) e.g., cefaclor, cefalexin, cefradine, cefuroxime, cefazolin, cefotaxime, ceftriaxone, cefoxitin, cefsulodin, ceftazidime, ceftizoxime Monobactams (bactericidal, P-lactam-like activity) e.g., aztreonam... 

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