other beta lactam Flashcards
What is Thienamycin?
A potent antibiotic with a carbapenam nucleus, effective against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa.
What is the role of the acylamino side chain in Thienamycin?
The acylamino side chain is absent in Thienamycin.
What is a significant structural feature of Thienamycin?
It has a double bond leading to high ring strain and increased beta-lactam ring reactivity.
Which bacteria is Thienamycin effective against?
- Gram-positive bacteria
- Gram-negative bacteria
- Pseudomonas aeruginosa
What is a disadvantage of Thienamycin?
It has poor stability in solution, being ten times less stable than Penicillin G.
What is Imipenem?
A derivative of Thienamycin, chemically stable and active against a variety of infections.
What is the role of cilastatin when administering Imipenem?
Cilastatin is a dehydropeptidase inhibitor co-administered to prevent the metabolism of Imipenem to toxic metabolites.
What is Meropenem’s activity compared to Imipenem?
Less active against Gram-positive bacteria but more active against Gram-negative bacteria.
What is a characteristic of Monobactams?
They have a monocyclic beta-lactam ring and are moderately active against a narrow group of Gram-negative bacteria.
What is Aztreonam and its clinical use?
A clinically useful monobactam administered intravenously, effective against Gram-negative aerobic bacteria and safe for patients allergic to penicillins.
What is Clavulanic acid’s primary function?
A powerful irreversible inhibitor of beta-lactamases, used to enhance the effectiveness of beta-lactam antibiotics.
What is Augmentin composed of?
Ampicillin and clavulanic acid.
What are Sulbactam and Tazobactam?
Suicide substrates for beta-lactamase enzymes with broader activity spectra than clavulanic acid.
Fill in the blank: Thienamycin is resistant to inactivation by most _______.
beta-lactamases.
True or False: Thienamycin is effective against Gram-positive bacteria but not against Gram-negative bacteria.
False.
What is the structural difference between clavulanic acid and Thienamycin?
Clavulanic acid has a sulphur replaced by oxygen in its structure.
What is the mechanism of action of clavulanic acid?
It acts as a suicide substrate for beta-lactamases.
What is the significance of the -1-hydroxyethyl side chain in Thienamycin?
It contributes to resistance against beta-lactamases.
