Aani Micro: Drugs- Antivirals and Antimicrobials

Question 1

How does acyclovir work?

Answer 1

Guanosine analogue - blocks viral thymidine kinase

Question 2

How to treat CMV?

Answer 2

1. ganciclovir (nucleoside analogue)
2. foscarnet
3. cidofovir

Question 3

Why does acyclovir not work for CMV?

Answer 3

It doesnt have thymidine kinase enzyme

Question 4

How to treat HSV?

Answer 4

Act Very Fast
Acyclovir
Valacyclovir
Famcyclovir

Question 5

Sideeffect of Ganciclovir?

Answer 5

Bone marrow toxicity

Question 6

How high should HBV levels be before you treat the patient?

Answer 6

> 2000 HBV DNA serum levels

Question 7

What is Palivizumab used for?

Answer 7

RSV

Question 8

What can treat RSV?

Answer 8

Palivizumab
OR
Ribavirin (guanosine analogue)

Question 9

How to treat Hep C?

Answer 9

Peg IFN Alpha
Or
Ribavarin

Question 10

Which types of Hep C are most successfully treated?

Answer 10

Genotypes 2 and 3

Question 11

Which types of Hep C are least successfully treated?

Answer 11

Genotypes 1 ,4,5 and 6

Question 12

Sideeffect of Ribavarin?

Answer 12

Haemolytic Anaemia

Question 13

Name some influenza neuraminidase inhibitors

Answer 13

Oseltamivir, Zanamivir and Sialic Acid

Question 14

Name an influenza drug that isnt a neuraminidase inhibitor- what does it do?

Answer 14

Amantidine - blocks M2 ion channel

MAN
M2

Question 15

Why is the risk of getting CMV higher in BM transplant if the pt already has CMV (seropositive)?

Answer 15

So basically the recipient is seropositive so already has CMV.
The recipient can control it but is getting BM transplant so losing their protective Abs. Because the donor is seronegative they don’t have protective Abs against CMV so the recipient doesnt get new ones and so they contract CMV.
If the donor was seropositive they’d likely be also donating protective Abs!

Question 16

Name the types of antimicrobials

Answer 16

• Cell wall synthesis inhibitors
• Protein synthesis inhibitors
• DNA synthesis inhibitors
• RNA synthesis inhibitors
• Cell membrane toxins
• Folate inhibitors

Question 17

What are the cell wall synthesis inhibitor groups and how do they work?

Answer 17

B lactams and Glycopeptides
B lactams inactivate transpeptidase enzymes that are needed for peptide cross links in the cell wall.
Glycopeptides inhibit transglycosidase enzymes

Question 18

Name the B lactams

Answer 18

PEN CAR SEF MON
Penicillins
Carbapenems
Cephalosporins
Monobactams

Question 19

What are the penicillins and talk about each key feature

Answer 19

In general the penicillins have good aerobic and anaerobic cover.

Penicillin - gram +. broken down by B lactamases

Amoxicillin - broad spec gram + and -. Also broken down by B lactamases.

Clavulanic acid - add to amoxicilin to protect against B lactamased = augmentin.

Flucloxacilin - Less active but resistant to B lactamases.

Piperacilin - Same as amoxicilin but with pseudomonas cover too

Question 20

What are the Carbapenems?

Answer 20

Meropenem and ertapenem

Stable to extended spectrum B lactamases but worried about carbapenemase enzymes building resistance.

Question 21

What are the Cephalosporins?

Answer 21

In general they are good for Gram -
 and cover pseudomomas.
Cephtriaxone - for meningitis
Cefuroxime
Ceftazidime 
BUT B lactamases are resistant to these AND you need to add metronidazole for anaerobic cover

Question 22

What are the positives and negatives about B lactam antibiotics?

Answer 22

+ Not v toxic
+ Can cross inflamed meninges

• Renally excreted
• Cross allergenic - anaphylaxis
• Short half life

Question 23

What are the glycopeptides?

Answer 23

Vancomycin and Teicoplanin

what the glycoPLANIN on TV

Question 24

Benefits of glycopeptides?

Answer 24

Gram + cover

Good for MRSA as resistant to B lactamases

Question 25

Negatives of glycopeptides?

Answer 25

- Only work against gram + cos too big to get through outer cell wall of gram - - Nephrotoxic - Slow

Question 26

What are the Protein Synthesis inhibitor antimicrobial drugs?

Answer 26

``` ATM CO Aminoglycosides Tetracyclins Macrolides Chloramphenicol Oxazolidinones ```

Question 27

Which ribosomal subunit to the Protein synthesis inhibitors each bind to?

Answer 27

``` Aminoglycosides - 30s Tetracyclines - 30s Macrolides - 50s Chloramphenicol - 50s Oxazolidinones -23s of 50s to prevent 70s ```

Question 28

Side effect of chloramphenicoles?

Answer 28

Grey baby syndrome and risk of aplastic anaemia

Question 29

What is chloramphenicole used for?

Answer 29

Eye drops

Question 30

What are the macrolides?

Answer 30

Erythromyciin/Clarithro/azithromycin

Question 31

What are the macrolides used for?

Answer 31

Intracellular organisms such as campylobacter and legionella

Question 32

What is a common tetracycline?

Answer 32

Doxycyclin

Question 33

What is doxycyclin used for?

Answer 33

Broad spec against intracellular pathogens e.g. Chlamydia and mycoplasma and Rikettsia

Question 34

What are the inhibitors of DNA synthesis antimicrobials?

Answer 34

Nitroimidazoles e.g. metronidazole | And Quinolones e.g. Ciproflox - all the FLOX.

Question 35

What are the Nitroimidazoles used for?

Answer 35

Good anearobic cover and against protozoa e.g. giarda

Question 36

What are the RNA synthesis inhibitor antimicrobials?

Answer 36

Rifamycins e.g. Rifampicin and Rifabutin

Question 37

How do RNA inhibitors work?

Answer 37

Bind to the DNA dependent RNA polymerase

Question 38

How do we use the RNA synthesis inhibitors?

Answer 38

NEVER alone as they develop resistance quickly. used for mycobacteria

Question 39

S/E of RNA synthesis inhibitors?

Answer 39

Orange secretions

Question 40

What are the cell membrane toxin antimicrobials?

Answer 40

Daptomycin and Colistin | Dapto for gram + and colistin for gram -

Question 41

When can you not used daptomycin?

Answer 41

Pneumonia- it is broken down by lung surfactant

Question 42

What are the inhibitors of folate metabolism? Give an example each and how they're used.

Answer 42

Sulphonamides e.g. sulfamethoxazole and Diaminopyrimidines e.g. trimethoprim. They are both combined to treat PCP

Question 43

How do you treat community vs hospital acquired UTIs?

Answer 43

Community- trimethoprim x 3 | Hospital - Co-amoxiclav (augmentin)

Question 44

How to treat mild community acquired pneumonia?

Answer 44

Amoxicililin (Penicillin B lactam)

Question 45

How to treat severe community acquired pneumonia?

Answer 45

Cefuroxime (cephalosporin B lactam) AND clarithromycin (Macrolide- protein synthesis inhibitor)

Question 46

How to treat hospital acquired pneumonia?

Answer 46

Cefuroxime (cehalosporin B lactam)

Question 47

Which skin pathogen is most common?

Answer 47

Staph Aureus

Question 48

How to treat Staph A skin infections?

Answer 48

Flucloxacillin (a norrow spec penicillin B lactam)

Question 49

Which organism causes Bacterial meningitis?

Answer 49

Meningiococcus/streptococcus

Question 50

How to treat bacterial meningitis in adults?

Answer 50

cafriaxone - think you want to shop the treee down if you have meningitis TREE-AXE. Ceftriaxone IV 2g bd Give amoxicillin instead if immunocompromised

Question 51

How to treat someone who has meningitis with encephalitis?

Answer 51

Cetfriaxone 2g bd AND acyclovir 10mg/kg tds

Question 52

How to treat C.Diff?

Answer 52

Metronidazole (stop offending Abx e.g. ceph)

Question 53

How to treat severe sepsis?

Answer 53

Cefuroxime, metronidazole and gentamicin

Question 54

How to treat neutropaenic sepsis?

Answer 54

Tazocin and gentamycin

Question 55

How to treat B haemolytic strep?

Answer 55

Benzylpenicillin

Question 56

Which organisms cause early onset sepsis in babies?

Answer 56

Group B strep E.Coli Listeria

Question 57

How to treat meningitis in kids?

Answer 57

<3 months : Cefotaxime AND amoxicillin - babies a taxing amo 3 months - 5 years: Caftriaxone 6 years +: Cefrtriaxone + Clarithromycin

Question 58

Which organisms cause meningitis in kids?

Answer 58

N.meningitidis all ages Strep Pneumonia all ages esp < 2 years HIB <3 months