Antimircobials

Question 1

How would you classify antimircobials?

Answer 1

Antibacterial, anitfungal, antiviral and antiprotozaol agents

Question 2

How can you classify antibacterial agent?

Answer 2

Bctericidial (able to kill bacteria) or bacteriostatic (inhibits bacteria) spectrum, either broad or narrow, target site and the mechanism of action and the chemical structure

Question 3

What are the ideal features of antimircobial agents?

Answer 3

Selectively toxic, few adverse effects, read site of infection, and oral or IV formulation and a long half life, and no interferance with other drugs

Question 4

What are the different classess of antibacterials and their mechansim of action?

Answer 4

Cell wall synthesis (beta lactams and glycopeptides) protein synthesis, terocyitnes, aminoglycosides, and cell membrane function polymixins and nucleic acid synthesis quiones

Question 5

How does penecillin function?

Answer 5

Penecillin binding protein has a function wihtin a cell, cross links two parts of the cell wall, and pencillin stops the protein doing its job

Question 6

How does vancomyicin function?

Answer 6

Active against gram positive organisms, sits on the cross linking chains and prevents penecillin binding protein doing its job to form the cross links

Question 7

How do fluroquinolones and syprofloxin function?

Answer 7

Nucleic acid synthesis disruption inbitis two enzymes, topoisomerase and DNA gyrase that deal with the replication of the nucleic acid, and stops the organisms multiplying

Question 8

What are the overall mecahansims of resistance that bacteria may develop?

Answer 8

Drug inactivating enzymes, genetic basis of antibiotic resistance, and horzinontal gene transfer, altered target and altered uptake

Question 9

How does the genetic transfer of resistance mechanisms work?

Answer 9

Horziontal gene transfer transfers the resistance mecahnism, and has a genetic basis that is embedded in chromosomes, and can be embedded in other bacteria by conjugation, transduction, and transformation

Question 10

What is the process that is used to measure antibiotic activity?

Answer 10

There is filter paper with a antibiotic in it, and when it diffuses out from disks this inhibits the growth of the bacteria and the size of the zone correlates with the resistance

Question 11

Name some of the beta lactam antimircobials?

Answer 11

Pencillins= benzympencillins, amaxocllin, fluxocillin, and co amaxoillin
Ceplalsporins- celfleaxin 1st celfatrioxine 3rd,
Coresporins-meromen

Question 12

What are the pencillins mainly active againsnt?

Answer 12

Gram positive organisms including the streptococci.
Penicllin is mainly activite against streptococci, whereas the fluoxacillin is active against the staphylococci and the streptococci,

Question 13

What are some of the feautres of amoxcillin?

Answer 13

Mainly active agaisnt gram positives but also has some activity agaisnt gram negatives.

Question 14

What are some of the features of the celphasporins?

Answer 14

Are part of the beta lactam groups, and have a broader spectrum than most that includes some gram negtaives, but have no activity against anaerobes- important example is cetratrioxone

Question 15

What are some of the features of cefratrixone?

Answer 15

Has good activity in the CSF therefore is used in the treatment of meningitis, however there are worries about the association of the organism with candidia

Question 16

What are some of the features of the carbonpennins?

Answer 16

B lactamases, include meropenin, generally safe in penicillin allergy and have a very broad spectrum including anaerobes, active against most but not all gram negatives.

Question 17

What are some of the features of tetracylcines?

Answer 17

Include tetracycline and doxycline, block protein synthesis. Usually used in gram positives but broad spectrum, active agaisnta typical pathogens in pneumonia and are useful in a penicillin allergy

Question 18

What are the actions of the aminoglycosides?

Answer 18

Block protein synthesis

Question 19

Name an aminoglycoside

Answer 19

Gentomycin

Question 20

What are some of the features of the activity of aminoglycosides?

Answer 20

Profound activity against gram negatives, and is potentially nephrotoxic (has a low thearputic window) and therefore is generally resevered for severe gram negative sepsis

Question 21

Name a macrolide

Answer 21

Erthomycin

Question 22

What are some of the features of treatment with macrolides?

Answer 22

Alternative to penicillin in a mild gram positive infection, and is also active against atypical respiratory pathogens

Question 23

Name a quinolone

Answer 23

Ciprofloxin

Question 24

How do quinolones have their function?

Answer 24

Inhibit DNA gyrase

Question 25

What are some of the features of treatment using quinolones?

Answer 25

Very active against gram negatives, and active against atypical pathogens, increasing resistance and a risk of c difficile

Question 26

Name the commonly used glycopeptides?

Answer 26

Vancomycin, adn tecippantin

Question 27

What are some of the features of treatment with vancomycin?

Answer 27

Narrow spectrum , active against most gram positive, some resistance from enterococci but less from staph, and there is also a narrow thearpeutic window

Question 28

How does trimethoprim work?

Answer 28

Inhibits folic aicd synthesis

Question 29

What might trimethoprim be combinded with?

Answer 29

Suplohonamides

Question 30

Name an antifungal and describe its course of action

Answer 30

Azoles, that are active agaisnt yeasts and moulds, and inhibit all mebrane synthesis, flucozide is used to treat condittal
OR
Pyogenes (nystatin)
Inhibit all membrane fuinction and nystatin is used for the topical treatment of candida

Question 31

How does the antiviral acicalvir work?

Answer 31

When phopshoyrlated inhibits viral DNA polymerase- used agasint hepres simplex and varicella zoster

Question 32

How does tamiflu work?

Answer 32

Inhibits viral neromidase, and is used agaisnt influenza A and B

Question 33

What is merhonidascole?

Answer 33

Is an antibacterial and an antiporozoal agent, and is active against anaerobic bacteria as erll as protozoa