Antibiotics Flashcards Preview

Pre Reg Pharmacy > Antibiotics > Flashcards

Flashcards in Antibiotics Deck (72)
Loading flashcards...
1
Q

Why are amimoglycosides inactive against anaerobes and streptococci?

A

These bacteria do not contain an oxygen dependent transport system

2
Q

Name the aminoglycosides

A

Gentamcin, amikacin, neomycin and tobramycin

3
Q

What are the two major side effects with aminoglycosides?

A

Nephrotoxicity and ototoxicity

4
Q

What drugs increase the chance of ototoxicity when prescribed with aminoglycosides

A

Loop diuretics and vancomycin

5
Q

What drug(s) increases the chance of nephrotoxicity with aminoglycosides?

A

Ciclosporin, cephalosporins or vancomycin

6
Q

Why must you use ibw in dose obese patients with gentamycin?

A

As this drug is distributed in body water and doesn’t deposit in fat

7
Q

Name the carbapenems

A

Meropenem
Ertapenem
Impenem with cilastatin

8
Q

What activity do carbapenems have?

A

Broad against Gram +ve, -ve and anaerobes

9
Q

Which carbapenem has no activity against pseudomonas?

A

Ertapenem

10
Q

Why is cilastatin given with imipenem?

A

Because enzyme activity in the kidneys deactivates the imipenem. Cilastatin inhib these enzymes

11
Q

Carbapenems have a risk a seizures but one less so. Because if this it can be used for cns infections. Which one is this?

A

Meropenem

12
Q

What are the important side effects regarding carbapenems? (3)

A

Abx associated colitis
Hypersensitivity reaction
Numerological toxicity, like seizures

13
Q

How does carbapenems interact with warfarin?

A

Kills natural gut flora that produce vitamin K therefore enhancing warfains affect

14
Q

Are carbapenems reserved Abx for severe infections?

A

Yes

15
Q

How does carbapenems interact with valperate?

A

Reduces plasma conc and efficacy

16
Q

How many generations of cephalosporins are there?

A

5

17
Q

Name the glycopeptides

A

Dalbavancin
Teicoplanin
Telavancin
Vancomycin

18
Q

What are the major side effects of vancomycin?

A

Nephrotoxicity

Ototoxicity

19
Q

What happens (if anything) when vancomycin is given as a rapid infusion?

A

A anaphylactoid reaction can occur. Therefore must be given for at least an hour

20
Q

Name the macrolides?

A

Clarithromycin
Azithromycin
Erythromycin

21
Q

What interaction is there with macrolides and SSRIs?

A

Both can prolong QT interval

22
Q

What are the important side effect of carbapenems? (3)

A

Antibiotic induced colitis
Hypersensitivity
Risk of neurological toxicity

23
Q

What carbapenem can be given for a CNS infection and why?

A

Meropenem because they have a lesser seizure producing potential

24
Q

What major interactions do carabpenems have?

A

Warfarin - due to the effect of natural gut flora lowering levels of vitamin k
Valporate - as they reduce its plasma concentration and efficacy

25
Q

What are cephalosporins indicated for?

A
Septicaemia
Pneumonia 
Meningitis 
Biliary tract infections
Peritonitis 
UTIs
26
Q

Cephalosporins penitrate the cns poorly. So why are they indicated in meningitis?

A

Because in meningitis the meninges are inflamed so they’re able to penitrate

27
Q

Give a brief description of 1st generation cephalosporins

A

This have a similar spectrum of activity as penicillin and are useful in respiratory infections, otis media, UTIs and skin/soft tissue infections

28
Q

In regards to cephalosporins. How does the 2nd generation differ from the 1st?

A

Has the same spectrum but is poorly absorbed so need to be taken with food

29
Q

In regards to cephalosporins how does the 3rd generation differ to previous generations?

A

Great spectrum of activity against gram -ve bacteria

30
Q

What generation of cephalosporins has the best spectrum of activity?

A

The fifth generation

31
Q

What is the target site for macrolides?

A

50s subunit in the ribosome

32
Q

What risk is there giving macrolides IV

A

Thrombophlebitis

33
Q

What affect can macrolides have on the liver?

A

Cholestatic jaundice

34
Q

What side effects can macrolides cause and which one causes them more frequently? (5)

A
  1. GI disturbances,
  2. throbophlebitis (when given IV),
  3. C.Diff, cholestatic jaundice,
  4. QT prolongation,
  5. ototoxicity (at high doses)
35
Q

Are erythromycin and clarithromycin CYP450 inducers or inhibitors?

A

Inhibitors

36
Q

Why are macrolides so good for LRTI?

A

As they cover atypical penicillin resistant organisms

37
Q

Name the quinolones

A
Levofloxacin 
Ciprofloxacin 
Moxifloxacin 
Delafloxacin
Ofloxacin
38
Q

Which quinolone has the greater activity?

A

Levofloxacin

39
Q

Which organism has a large prevalence of resistance to quinolones?

A

Streptococci

40
Q

What are the MRHA warning regarding quinolines?

A
  1. They may indice convulsions in patients with or without a history
  2. Tendon damage can occur
  3. High risk of aortic aneurysms
41
Q

When should caution be taken when using quinolones? (6)

A
  1. Cardiac conditions as can prolong QT intervals
  2. Pts who have a pre disposition to seizures
  3. Diabetes as can affect blood sugars
  4. G6PD deficiency
  5. Children as can cause arthopathy in weight baring joints
  6. UV exposure
42
Q

Are quinolones bactericidal or bacteristatic? And what’s their mechanism of action?

A

Bactericidal by inhibiting DNA synthesis

43
Q

With quinolone has activity against pseudomonas?

A

Ciprofloxacin

44
Q

What are the major side effects of quinolones? (3)

A
  1. Low seizure threshold
  2. Inflame and rupture tendons
  3. Prolong QT interval
45
Q

What interactions must you be weary of in regards to quinolones?

A

Calcium and zinc as they reduce absorption
NSAIDs due to effects of seizure threshold
Prednisolone as they increase tendon rupture risk
Any drug that prolongs the QT interval

Also Ciprofloxacin inhibits some CYP450 enzymes so increases the concentration of theophylline

46
Q

Name the tetracyclines

A
Demeclocycline
Doxycyline 
Lymecycline
Minocycline
Oxytetracycline 
Tetracycline 
Tigecycline
47
Q

What are the main indications for tetracyclines?

A

Chlamydia
Acne
LRTI

48
Q

Which tetracycline has the biggest spectrum of activity?

A

Minocycline

49
Q

What serious side effect is minocycline associated with?

A

It can cause lupus erythematosus like syndrome and irreversible pigmentation

50
Q

Why must you not give tetracyclines to pregnant and breast feeding women?

A

As they can affect the development of the babies bones

51
Q

What is the target site for tetracyclines?

A

The 30s ribosome subunit

52
Q

What are the 5 major side effects of tetracyclines?

A

Oesphagael irritation
Photosensitivity
Discolouration and/or hypoplasia of the teeth enamel in children
Hepatotoxicity
Intercraneal HTN (headaches and blurred vision)

53
Q

What are the interactions to be mindful of with tetracyclines?

A

Ca, antacids and ieon (chelating effect)

Enhance the affect of warfarin due to its effect on gut flora

54
Q

Why must you be mindful of renal function when giving tetracyclines?

A

They can increase urea and also when impaired tetracycline clearance is reduced

55
Q

What must you be mindful about when giving someone demeclocycline and syndrome of inappropriate ADH?

A

Demeclocycline can increase the patients sodium

56
Q

What is metronidazole used for?

A

Treating anaerobes and protozoa

57
Q

What is the mechanism of action of metronidazole?

A

When in an anaerobic bacteria they are reduced into nitroso free radicals interfering with FNA synthesis

58
Q

When is metronidazole not recommended in women?

A

During their menstruation

59
Q

What are the significant side effects of metronidazole?

A

GI upset

With prolonged use can cause peripheral & optic neuropathy, seizures, encephalopathy and leucopenia

60
Q

What antibiotics can you not have alcohol with?

A

Metronidazole as it inhibits acetaldehyde dehydrogenase

61
Q

What are the most common Bacteria for a skin infection

A

Staph.Aureus
Streptococci.Pyogenes
Pusedomonus.A

62
Q

What are the common organisms associated with meningitis?

A

Streptococci pneumoniae
Meningcocci
H.Influenzea
Listeria

63
Q

What organisms are commonly associated with eye infections?

A

Staph.Aureus
Clamidyia
Gonorrhea

64
Q

What organism is associated with ear infections ?

A

Streptococci pneumoniae

65
Q

What organisms are associated with URTI?

A

Strep.pyogenes

Haemophilia influenzae

66
Q

What is the organism associated with infections of the stomach?

A

H.pylori

67
Q

Name the anti psudomonal penicillins

A

Tazocin

Ticarcillin with clavulanic acid

68
Q

Name the broad spectrum penicillins

A

Amoxicillin
Ampicillin
Co-amoxiclav
Co-fluampicil

69
Q

Name the beta lactamase sensitive penicillin

A

Benzylpenicillin

Phenoxylmethylpenicillin

70
Q

Name the penicillinase resistant penicillin

A

Flucloxacillin

71
Q

What is the interaction with penicillins and MTX?

A

Reduces the renal clearance

72
Q

What hepatic affects can Amoxcilin or co-amoxiclav cause?

A

Cholestatic or hepatitis