Antibiotics Flashcards
How do penicillins work?
Inhibiting cell wall synthesis by preventing the cross linking of peptidoglycan subunits.
Are penicillins bacteriostatic or bacteriocidal?
Bacteriocicdal
How are penicillins excreted?
Via the kidneys
Atre penicillins safe in pregnancy?
Yes
Name three groups of antibiotics that act on the bacterial cell wall
Penicillins
Cephlasporins
Glycopeptides
Give an example of a glycopeptide antibiotic
Vancomycin
Give an example of a cephlasporin antibiotic
Ceftriaxone
What penicillin gives gram positive cover only?
Flucloxacillin
What peniciliin given gram negative and gram positive cover?
Amoxicillin
Co amoxiclav
Pipercillin/Tazobactam
What organisms are sensitive to flucloxacillin?
Gram positive staphylococci and streptococci
What does the clavulanic acid do in co amoxiclav?
Inhibits the action of the beta lactamase enzyme produced by bacteria
What is temociilin active against?
Coliforms
How do glycopeptide antibiotics work?
Bind to the end of the growing peptide chain and prevent cross linking. This then weakens the bacterial cell wall.
Are glycopeptides bacteriocidal or bacteriostatic?
bacteriocidal
Do glycopeptides work on gram negative organisms, gram positive organisms or both?
ONLY gram positive
Name the main groups of antibiotics that inhibit protein synthesis
Macrolides Tetracyclines Aminoglycosides Clindamycin Chloramphenicol
Name three macrolide antibiotics
Erythromycin
Clarithromycin
Azithromycin
Name an aminoglycoside antibiotic
Gentamicine
Are antibiotics that inhibit protein synthesis bacteriostatic or bacteriocidal?
Bacteriostatic. They attach to bacterial ribosomes and stop further protein synthesis. However, protein synthesis can usually resume once the antibiotic is removed.
How are macrolide antibiotics excreted?
Liver
Are macrolides lipophillic or lipophobic?
Lipophillic; they pass through cell membranes easily. Useful for infections where bacteria hide from the host’s immune system.
How is gentamicin administered and why?
Must be given IV or IM as it is not absorbed from the gut.
What infections are treated with gentamicin?
It is active against gram negative aerobic organisms such as coliforms and pseudomonas aeruginosa. It is used in hospital for treating serious gram negativ infection.
What are some of the risks of gentamicin.
Toxic to the kidneys
VIIIth cranial nerve damage (causes deafness and dizziness)
What groups of antibiotics act on bacterial DNA?
Metronidazole
Trimethoprim
Fluroquinolones
What kind of organisms is metronidazole active against?
True anaerobic
What four antibiotics are associated with an increased risk of C diff?
Cephlasporins
Co - amoxiclav
Ciprofloxacin
Clindamycin
