Cell Wall Inhibitors in Antimicrobials

<p>Rashes and anaphylaxis</p> Signup and view all the answers

<p>At the 7-position</p> Signup and view all the answers

<p>Certain β-lactamases</p> Signup and view all the answers

<p>Seizures</p> Signup and view all the answers

<p>It increases blood levels of penicillins.</p> Signup and view all the answers

<p>Ampicillin</p> Signup and view all the answers

<p>β-Lactamase production</p> Signup and view all the answers

<p>Extended spectrum of gram-negative bacteria activity</p> Signup and view all the answers

<p>Nafcillin</p> Signup and view all the answers

<p>Piperacillin and tazobactam</p> Signup and view all the answers

<p>Its associated toxicity</p> Signup and view all the answers

<p>Absorption of β-lactam antibiotics</p> Signup and view all the answers

<p>Infections caused by penicillinase-producing staphylococci</p> Signup and view all the answers

<p>Glomerular filtration</p> Signup and view all the answers

<p>Seizures</p> Signup and view all the answers

<p>Gram-negative microorganisms, including Enterobacteriaceae</p> Signup and view all the answers

<p>Compounding with cilastatin</p> Signup and view all the answers

<p>They protect antibiotics from being hydrolyzed by beta-lactamase enzymes.</p> Signup and view all the answers

<p>They have a low immunogenic potential.</p> Signup and view all the answers

<p>Ertapenem</p> Signup and view all the answers

<p>Neutropenia</p> Signup and view all the answers

<p>Penicillin levels in the prostate are insufficient to be effective against infections due to inadequate penetration.</p> Signup and view all the answers

<p>Probenecid inhibits the secretion of penicillins by competing for the active tubular secretion via the organic acid transporter.</p> Signup and view all the answers

<p>Reactions can range from rashes to anaphylaxis, with approximately 10% of patients reporting allergies.</p> Signup and view all the answers

<p>In patients with impaired renal function, some metabolism of penicillin G may occur, requiring dosage adjustments.</p> Signup and view all the answers

<p>Cytopenias may develop in patients receiving penicillins for more than 2 weeks, necessitating regular blood count monitoring.</p> Signup and view all the answers

<p>The core four-membered β-lactam ring is fundamental to penicillins.</p> Signup and view all the answers

<p>Structural changes on the acyl side chain at the 7-position alter antibacterial activity.</p> Signup and view all the answers

<p>Penicillins interfere with bacterial growth by binding to penicillin-binding proteins (PBPs) and disrupting cell wall synthesis.</p> Signup and view all the answers

<p>Gram-negative bacteria have an outer lipopolysaccharide membrane that acts as a barrier to penicillins.</p> Signup and view all the answers

<p>Neurotoxicity, including seizures, can occur if penicillins are injected intrathecally or if very high blood levels are reached.</p> Signup and view all the answers

<p>Natural penicillins are clinically significant for treating infections caused by various gram-positive organisms and certain gram-negative organisms.</p> Signup and view all the answers

<p>Cephalosporins are generally more resistant than penicillins to certain β-lactamases.</p> Signup and view all the answers

<p>Penicillin G is preferred for treating syphilis and gas gangrene.</p> Signup and view all the answers

<p>The R side chain affects the antimicrobial spectrum, stability to stomach acid, and susceptibility to β-lactamases.</p> Signup and view all the answers

<p>Penicillin V is more acid stable than penicillin G, allowing it to be used in oral formulations.</p> Signup and view all the answers

<p>The size, charge, and hydrophobicity of the specific β-lactam antibiotic determine the susceptibility of PBPs.</p> Signup and view all the answers

<p>They are resistant to staphylococcal penicillinase.</p> Signup and view all the answers

<p>Second-generation cephalosporins have greater activity against gram-negative organisms.</p> Signup and view all the answers

<p>They play a crucial role in the treatment of infectious diseases.</p> Signup and view all the answers

<p>Cefepime has a wide antibacterial spectrum, effective against aerobic gram-negative organisms.</p> Signup and view all the answers

<p>Ceftaroline is the only β-lactam with activity against MRSA.</p> Signup and view all the answers

<p>Resistance to ceftazidime is increasing; its use should be evaluated on a case-by-case basis.</p> Signup and view all the answers

<p>Third-generation cephalosporins are associated with the development of C. difficile infection.</p> Signup and view all the answers

<p>Ceftaroline's twice-daily dosing regimen limits its use outside of institutional settings.</p> Signup and view all the answers

<p>Resistance is mainly due to the hydrolysis of the β-lactam ring by β-lactamases or reduced affinity for penicillin-binding proteins (PBPs).</p> Signup and view all the answers

<p>Many cephalosporins have poor oral absorption, necessitating parenteral administration for effective treatment.</p> Signup and view all the answers

<p>Ceftriaxone and cefotaxime are effective in treating neonatal and childhood meningitis caused by H. influenzae.</p> Signup and view all the answers

<p>Ceftriaxone is excreted primarily through the bile into the feces, allowing its use in patients with renal insufficiency.</p> Signup and view all the answers

<p>Cross-reactivity between penicillins and cephalosporins is approximately 3% to 5%.</p> Signup and view all the answers

<p>Carbapenems differ from penicillins by having a carbon atom replacing the sulfur atom in the thiazolidine ring.</p> Signup and view all the answers

<p>Imipenem is known to resist hydrolysis by most β-lactamases.</p> Signup and view all the answers

<p>Ertapenem lacks coverage against P. aeruginosa, Enterococcus species, and Acinetobacter species.</p> Signup and view all the answers

<p>It protects imipenem from renal dehydropeptidase, prolonging its activity in the body.</p> Signup and view all the answers

<p>Meropenem can reach therapeutic levels in bacterial meningitis even without inflammation.</p> Signup and view all the answers

<p>Aztreonam lacks activity against gram-positive bacteria and anaerobes.</p> Signup and view all the answers

<p>High levels of imipenem may provoke seizures.</p> Signup and view all the answers

<p>They inactivate beta-lactamases, protecting the antibiotics from hydrolysis and preserving their antimicrobial activity.</p> Signup and view all the answers

<p>Nausea, vomiting, and diarrhea are common side effects.</p> Signup and view all the answers

<p>Aztreonam can be administered IV or IM, and it may accumulate in patients with renal failure.</p> Signup and view all the answers

<p>Monobactams have a β-lactam ring that is not fused to another ring.</p> Signup and view all the answers

<p>Resistance is driven by alterations in binding affinity to peptidoglycan precursors.</p> Signup and view all the answers

<p>Oral vancomycin has poor absorption, making it mainly effective for managing C. difficile infections in the colon.</p> Signup and view all the answers

<p>Lipoglycopeptides are more potent than vancomycin and may have activity against vancomycin-resistant isolates.</p> Signup and view all the answers

<p>They inhibit bacterial cell wall synthesis and disrupt membrane potential, which minimizes resistance selection.</p> Signup and view all the answers

<p>Telavancin has a risk of nephrotoxicity and interactions with certain medications known to prolong the QT interval.</p> Signup and view all the answers

<p>Daptomycin is indicated for complicated skin infections and bacteremia but should never be used to treat pneumonia.</p> Signup and view all the answers

<p>Daptomycin is administered IV once daily.</p> Signup and view all the answers

<p>Lipoglycopeptides inhibit bacterial cell wall synthesis, similar to vancomycin.</p> Signup and view all the answers

<p>The β-lactam ring structure is crucial as it allows penicillins to bind to penicillin-binding proteins (PBPs), disrupting bacterial cell wall synthesis and leading to cell death.</p> Signup and view all the answers

<p>The R side chains of penicillins affect their antimicrobial spectrum, stability to stomach acid, and susceptibility to β-lactamases, thus influencing their clinical use.</p> Signup and view all the answers

<p>Gram-negative organisms have an outer lipopolysaccharide membrane that acts as a barrier to penicillins, preventing their effective entry into the bacterial cell.</p> Signup and view all the answers

<p>Penicillins disrupt bacterial cell wall synthesis by binding to PBPs and inhibiting transpeptidation, leading to a weakened cell wall and eventual cell lysis.</p> Signup and view all the answers

<p>Penicillin G is commonly used to treat infections such as gas gangrene (caused by Clostridium perfringens) and syphilis (caused by Treponema pallidum).</p> Signup and view all the answers

<p>Penicillin V is more acid-stable than penicillin G, making it suitable for oral administration, while penicillin G requires injection due to its instability in stomach acid.</p> Signup and view all the answers

<p>Porins are water-filled channels that allow certain substances to pass through the outer membrane of gram-negative bacteria, influencing the entry of penicillins and contributing to resistance.</p> Signup and view all the answers

<p>Some viridans streptococci have developed resistance to penicillin, which poses a challenge for treatment as these bacteria are typically sensitive to natural penicillins.</p> Signup and view all the answers

<p>Gram-positive bacteria secrete β-lactamases extracellularly, while gram-negative bacteria inactivate β-lactam drugs in the periplasmic space.</p> Signup and view all the answers

<p>Fosfomycin inhibits the enzyme enolpyruvyl transferase, blocking cell wall synthesis.</p> Signup and view all the answers

<p>Modified PBPs have a lower affinity for β-lactam antibiotics, necessitating higher drug concentrations to inhibit bacterial growth.</p> Signup and view all the answers

<p>The most common adverse effects include diarrhea, vaginitis, nausea, and headache.</p> Signup and view all the answers

<p>Fosfomycin's unique structure and mechanism of action make cross-resistance with other antimicrobials unlikely.</p> Signup and view all the answers

<p>The complex cell wall of gram-negative bacteria, including porins and efflux pumps, limits the penetration and effectiveness of β-lactam antibiotics.</p> Signup and view all the answers

<p>The route of administration is determined by the drug's stability to gastric acid and the severity of the infection.</p> Signup and view all the answers

<p>The use of polymyxins is limited due to the increased risk of nephrotoxicity and neurotoxicity.</p> Signup and view all the answers

<p>Food decreases the absorption of dicloxacillin as it increases gastric emptying time, which allows the drug to be destroyed by stomach acid.</p> Signup and view all the answers

<p>Polymyxins are effective against most clinically important gram-negative bacteria, including P.aeruginosa and E.coli.</p> Signup and view all the answers

<p>Depot forms, like procaine penicillin G and benzathine penicillin G, are administered IM and release the drug slowly into circulation.</p> Signup and view all the answers

<p>Amoxicillin is stable in acid and is readily absorbed, whereas only one-third of penicillin V's oral dose is absorbed due to the acidic environment.</p> Signup and view all the answers

<p>β-lactam antibiotics, including penicillins, cross the placental barrier without teratogenic effects, ensuring treatment without harm to the fetus.</p> Signup and view all the answers

<p>First-generation cephalosporins are resistant to staphylococcal penicillinase and provide modest activity against Proteus mirabilis, E. coli, and K. pneumoniae.</p> Signup and view all the answers

<p>Second-generation cephalosporins have greater activity against gram-negative organisms while having weaker activity against gram-positive organisms.</p> Signup and view all the answers

<p>Third-generation cephalosporins provide enhanced activity against gram-negative bacilli, including strains producing beta-lactamase.</p> Signup and view all the answers

<p>Cefepime exhibits a wide antibacterial spectrum, effective against both gram-positive and gram-negative organisms and must be administered parenterally.</p> Signup and view all the answers

<p>Ceftaroline is the only beta-lactam in the U.S. that is effective against MRSA.</p> Signup and view all the answers

<p>Ceftazidime should be used with caution due to its association with increasing resistance and the development of C. difficile infections.</p> Signup and view all the answers

<p>Ceftaroline's twice-daily dosing limits its use outside of institutional settings.</p> Signup and view all the answers

<p>Advanced-generation cephalosporins, particularly ceftaroline, provide broad-spectrum coverage against both gram-positive and gram-negative bacteria, including resistant strains.</p> Signup and view all the answers

<p>It is primarily used for treating infections caused by resistant Enterobacteriaceae and multidrug-resistant P.aeruginosa.</p> Signup and view all the answers

<p>It combines a carbapenem with a β-lactamase inhibitor to treat complicated UTIs, including pyelonephritis.</p> Signup and view all the answers

<p>Common adverse events include nephrotoxicity, infusion-related reactions like red man syndrome, and ototoxicity.</p> Signup and view all the answers

<p>Tazobactam acts as a β-lactamase inhibitor, enhancing the effectiveness of ceftolozane against resistant bacteria.</p> Signup and view all the answers

<p>Ceftazidime-avibactam is indicated for intra-abdominal infections and complicated UTIs.</p> Signup and view all the answers

<p>Vancomycin is active against aerobic and anaerobic gram-positive bacteria, including MRSA and Enterococcus spp.</p> Signup and view all the answers

<p>They are reserved for treating infections caused by multidrug-resistant pathogens due to their extensive antimicrobial activity.</p> Signup and view all the answers

<p>Meropenem-vaborbactam is effective against a broad spectrum of β-lactamases except metallo-β-lactamases.</p> Signup and view all the answers

<p>Semisynthetic penicillins, such as ampicillin and amoxicillin, have extended antimicrobial activity against gram-negative bacteria due to their modified R groups, which allow them to target organisms like E.coli and H.influenzae.</p> Signup and view all the answers

<p>β-lactamase inhibitors, such as clavulanic acid, increase the effectiveness of aminopenicillins like ampicillin by preventing the hydrolysis of the β-lactam ring, which some bacteria produce to resist these antibiotics.</p> Signup and view all the answers

<p>Antistaphylococcal penicillins, such as methicillin and nafcillin, are primarily used to treat infections caused by penicillinase-producing staphylococci, including MSSA, but have minimal activity against gram-negative infections.</p> Signup and view all the answers

<p>Piperacillin is an antipseudomonal penicillin effective against P.aeruginosa, and its combination with tazobactam extends its antimicrobial spectrum to include penicillinase-producing organisms.</p> Signup and view all the answers

<p>Bacteria can develop resistance to β-lactam antibiotics through β-lactamase production, decreased drug permeability, and altered penicillin-binding proteins (PBPs).</p> Signup and view all the answers

<p>The gene responsible for β-lactamase production can be acquired through plasmid transfer between bacteria, leading to a rapid spread of resistance against β-lactam antibiotics.</p> Signup and view all the answers

<p>Amoxicillin is employed prophylactically by dentists in high-risk patients to prevent bacterial endocarditis before dental procedures.</p> Signup and view all the answers

<p>Methicillin is mainly utilized in laboratory settings to identify MRSA (methicillin-resistant Staphylococcus aureus) due to its toxicity and limited efficacy in clinical settings.</p> Signup and view all the answers