Penicilloic Acid and Antibiotic Deactivation Quiz
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Questions and Answers

Penicilloic acid has a negligible tendency to reclose to the corresponding penicillin, so this reaction is essentially irreversible under physiologic conditions. Because the β-lactam ring is an essential portion of the pharmacophore, its hydrolysis deactivates the ______.

antibiotic

A fairly significant degree of hydrolysis also takes place in the ______.

liver

The bacterial enzyme, βlactamase, catalyzes this reaction also and is a principal cause of bacterial resistance in the ______.

clinic

Alcohols and amines bring about the same cleavage reaction, but the products are the corresponding esters and ______.

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

A reaction with a specific primary amino group of aminoglycoside antibiotics is of clinical relevance as it inactivates penicillins and ______.

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

Small molecules that are not inherently antigenic but react with proteins to produce antigens in this manner are called ______.

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

These changes have been incorporated into a number of marketed and experimental ______ (e.g., cefuroxime, ceftizoxime, ceftazidime, cefixime)

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

The cephalosporins are believed to act in a manner analogous to that of the ______ by binding to the penicillin-binding proteins followed by cell lysis

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

Cephalosporins are bactericidal in clinical ______

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

Susceptible cephalosporins can be hydrolyzed by ______ before they reach the penicillin-binding proteins

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

Allergenicity is less commonly experienced and is less severe with ______ than with penicillins

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

Most cephalosporins have generic names beginning with ______- or ______-

<p>cef, ceph</p> Signup and view all the answers

The facility with which the β-lactam bond of the cephalosporins is broken is modulated by the nature of the C-7 substituent (analogous to the ______)

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

The isomerization of the olefinic linkage to C-3,4 leads to great losses in antibiotic ______

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

Most cephalosporins are comparatively unstable in ______ solutions

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

Cephalosporins with an acetyl group in the side chain are subject to enzymatic hydrolysis in the ______

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

A hydroxy moiety is a poor leaving group, so this change is considerably deactivating with respect to breakage of the β-lactam ______

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

The penicillin binding proteins have an absolute requirement for a free carboxyl group to mimic that of the terminal carboxyl of the ______ moiety

<p>d-alanyl-d-alanine</p> Signup and view all the answers

Cefpodoxime Proxetil is mainly used for respiratory tract infections, otitis media, and pharyngitis, as well as urinary tract infections by susceptible microorganisms. It is a ______.

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

Cefpodoxime Proxetil is cleaved enzymically to isopropanol, CO2, acetaldehyde, and cefpodoxime in the ______.

<p>gut wall</p> Signup and view all the answers

Cefpodoxime Proxetil has better anti–Staphylococcus aureus activity than cefixime and is used to treat pharyngitis, urinary tract infections, upper and lower respiratory tract infections, otitis media, skin and soft tissue infections, and ______.

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

Cefdinir has an enhanced anti–gram-positive activity. It has reasonable resistance to ______.

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

Cefditoren Pivoxil is an orally active ______.

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

Cefditoren Pivoxil is indicated for mild to moderate infections in adults and adolescents with chronic bronchitis, pharyngitis/tonsillitis, and uncomplicated skin infections associated with ______ bacteria.

<p>gram-negative</p> Signup and view all the answers

Its molecular mode of action is closely similar to that of the penicillins, cephalosporins, and ______, the action being characterized by strong affinity for PBP-3, producing filamentous cells as a consequence.

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

The monobactams demonstrate that a fused ring is not essential for antibiotic activity.The α-oriented methyl group at C-2 is associated with the stability of ______ toward β-lactamases.

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

The protein binding is moderate (∼50%), and the drug is nearly unchanged by metabolism. Aztreonam is primarily excreted in the ______.

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

Aztreonam is used against severe infections caused by gramnegative microorganisms (mainly urinary tract, upper respiratory tract, bone, cartilage, abdominal, obstetric, and gynecologic infections and ______).

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

The α-oriented methyl group at C-2 is associated with the stability of aztreonam toward ______.

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

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