Antibiotics

Question 1

How do penicillins work?

Answer 1

Beta Lactam antibiotics

Inhibit transpeptidation reaction during synthesis of the peptidoglycan cell wall

Question 2

How have bacteria become resistant to some penicillins?

Answer 2

Some have beta-lactamase enzyme which can cut open the beta lactam ring in the drug so the antibiotic is no longer effective.
Note some penicllins are naturally beta-lactam resistant.

Question 3

Beta-lactamase inhibitors have been created, give me some examples of them.

Answer 3

Piperacillin and Tazobactam = Tazocin

Amoxicillin and Clauvonic Acid = co-amoxiclav

Question 4

List some names of penicillin antibiotics.

Answer 4

Benzylpenicllin
Amoxicillin
Flucloxocillin
Piperacillin

Question 5

List some names of cephalosporins.

Answer 5

Cefotaxime

Cefalexin

Question 6

List some names of glycopeptides and their indication.

Answer 6

Vancomycin
Teicoplanin
Reserved for serious gram +ve infections e.g. MRSA, C.Diff

Question 7

List some examples of Tetracyclines and what they are used for?

Answer 7

Doxycycline, Lymocycline

Used to treat chlamydia, acne, chronic bronchitis

Question 8

List some of the important side effects of tetracyclines.

Answer 8

GI Disturbance - always give with food
Affects calcified tissue - so avoid in children and in pregnancy
Photosensitivity - warn patient
Hepatotoxicity

Question 9

List some examples of aminoglycosides and what is special about their route of administration?

Answer 9

Gentamycin, Streptomycin

Highly polar, so not absorbed in GI tract, have to be given parenterally

Question 10

List some examples of Macrolides. They have a similar spectrum to penicillin, why is this useful?

Answer 10

Erythromycin, Clarithromycin,

Can be used as a substitute in penicillin allergic patients.

Question 11

Why is clindamycin used less frequently now?

Answer 11

Associated with antibiotic associated colitis which can be fatal - most common in middle aged/elderly women post-op. Should be discontinued immediately if diarrhoea develops

Question 12

What side effects is systemic chloramphenicol associated with? How does this restrict its use?

Answer 12

Associated with severe haematological side effects - therefore reserved ONLY for the treatment of severe life threatening infections
Is available in eye and ear drop form however.

Question 13

List some of the common, well recognized side effects from treatment with any antibiotic?

Answer 13

Antibiotic associated diarrhoea
Oral and Vaginal Candidiasis
Colonisation or infection by resistant bacteria

Question 14

List the beta lactam containing antibiotics and therefore the ones to be aware of in beta lactam allergy.

Answer 14

Penicillins
Cephalosporins
Carabapenems
Aztreonam

Question 15

What antibitoics are used to treat C.Diff

Answer 15

Metronidazole

Vancomycin

Question 16

What antibiotic is most commonly used to treat skin infections?

Answer 16

Flucloxacillin

Question 17

Human cells and fungal cells are both eukaryotic, what is different about them?

Answer 17

Human cells use cholesterol to make cell membrane, whereas fungal cells use ergosterol

Question 18

Name the two anti-fungals we need to know according to the formulary and how they work

Answer 18

NYSTATIN is a polyene, binds to ergosterol and forms pores which makes the membrane leaky
FLUCLONAZOLE is a azole and prevents formation of ergosterol