Infections- Antibiotics Flashcards
(86 cards)
1
Q
Which antibiotic is most associated with causing antibiotic associated colitis
A
Clindamycin
2
Q
What are key side effects of linezolid? (gram positive)
A
Optic neuropathy - visual disorders
blood disorders
3
Q
What are key interactions of linezolid?
A
SSRI/TCA/MAOI - hypertensive crisis
sympathomimetics, dopaminergics, opioids, 5-HT1 agonists
Tyramine rich foods
4
Q
Can chloramphenicol be used in pregnancy? why?
A
No - C/I - causes grey baby syndrome, 3rd trimester
5
Q
What is metronidazole active against and what does it treat
A
Anaerobic and protozoa
- anaerobics e.g. dental, Abx associated colitis, BV, H.pylori, rosacea
Protozoa - vaginal trichomoniasis, giardiasis
6
Q
What are common side effects of metronidazole?
A
Furred tongue
Oral mucositis
taste disturbance
GI disturbance
7
Q
What colour can nitrofurantoin turn urine?
A
Yellow/brown
8
Q
2 counselling points for nitrofurantoin
A
With food
Colours urine yellow/brown
9
Q
what is the renal cut off for nitrofurantoin?
A
<45
10
Q
what are aminoglycosides active against
A
Gram -ve
P. aureiginosa
11
Q
What route are aminoglycosides given?
A
IV in systemic infections-not absorbed by gut
Also have tobramycin via inhaler (pseudomonal in CF)
12
Q
When would you avoid a once daily dosing regimen for gentamicin?
A
Renal impairment <20
HACEK or gram positive endocarditis
burns
13
Q
When would you monitor plasma levels of gent on a multiple daily dose regimen?
A
After 3-4 doses
14
Q
For general multiple daily dose use - what are plasma targets for gent?
A
Post dose peak = 5-10mg/mL
Pre dose trough = <2mg/mL
15
Q
For endocarditis, what are gentamicin target levels
A
post dose peak 3-5mg/mL
pre dose trough <1mg/mL
16
Q
In renal impairment - what adjustment is made for gentamicin
A
Increased interval (in severe e.g. <30 - reduce dose, avoid once daily regimens in <20)
17
Q
What is an MHRA warning for gentamicin
A
Risks histamine related adverse reactions with some batches - monitor for histamine reactions
18
Q
In what situation is oral vancomycin favoured over IV?
A
C.diff - want it to stay in the intestine/bowel
19
Q
what are target levels for vancomycin
A
Pre dose trough 10-20
15-20 in endocarditis
20
Q
What are common side effects of vancomycin
A
Red man syndrome if IV too quick Nephrotoxicity Blood dysgrasias skin and SJS Ototoxicity Thromboplebitis - pain/inflammation at site
21
Q
what is an important side effect of tetracyclines
A
benign intracranial hypertension - stop if headache/visual disturbances
22
Q
What are contraindications of tetacyclines
A
children <12
Pregnancy ^ BF
23
Q
What are the 3 key areas of tetracyclines counselling
A
Photosensitivity
decreased absorption
oesophageal iritation
24
Q
Which tetracyclines cause photosensitivity?
A
DD
- doxyclcine
- demeclocycline
25
Which tetracyclines have decreased absorption when given with antacids containing al/ca/mg/zinc and also must avoid milk? what is the cautionary label?
DOT
- demeclocycline
- oxytetracycline
- tetracycline
Label: do not take indigestion remedies/antacids containing aluminium, magnesium, calcium or zinc 2 hours before or after taking abx
chelates with the calcium/milks so no absorption
26
Which tetracyclines cause oesophageal irritation? and what is the counsselling point?
DMT:
- doxycycline
- minocycline
- tetracycline
Swallow whole with plenty of fluid during meals whilst sitting or standing
27
What are key side effects of quinolone abx?
- seizures
- tendon damage
- QT prolongation
- joint diseases/arthritis-avoided in preg/child
- psychiatric reactions
- hypersensitivity e.g. SJs
28
Are quinolones active against MRSA?
NO - resistance
29
What medications would you avoid with quinolone abx? (interaction)
- other drugs that prolong QT e.g. SSRIs, amiodarone, macrolides, antipsychotics
- Theophylline - risk of theophylline toxicity, seizures S/E of both
- Drugs lowering seizure threshold e.g. NSAIDS
- also note that quinolones (ciprofloxacin) is an enzyme inhibitor
30
What are 3 counselling points for quinolone abx
- driving - impaired performance/drowsy
- protect skin from sunlight for ofloxacin
- leave a 2 hour gap before or after taking quinolone for antacids containing zinc/iron
- avoid milk/dairy for cipro/nor
31
Which macrolide has more GI effects, clari or ery?
Erythromycin
32
What is the dose of azithromycin OTC for chlamydia?
1g single dose
33
What are key side effects of macrolides
```
GI effects (esp Ery)
QT prolongation
Hepatotoxicity
Ototoxicity at high dose
```
Clari: - taste disturbance, tooth and tongue discolouration
34
What are counselling points for macrolides
take with/after food
| Clari: taste disturbance/tooth/tongue discolouration
35
What is the interaction of macrolides and statins and how to overcome?
Macrolids enzyme inhibitors, (ery/clari) - increeased myopathy risk - hold statin during abx coursee
36
What is a counselling point for clarithromycin
May cause taste disturbance, toothe and tongue discoloration
37
What antibiotics have cross sensitivity with penicillin allergy
Carbapenems
cephalosporins
monobactams
38
What penicillins are narrow spectrum
```
Pen G (benzyl)
Pen V (phenoxy)
```
39
Can penicillins be used in CNS infections? what is an exception?
No because they poorly penetrate cerebospinal fluid. Only exception is use in meningitis because meninges are inflamed so can pass through
40
What pencillins have anti-pseudomonal activity
Tazozin - piperacillin
| Ticaricillin (with clauvulanic acid)
41
what penicillin is penicillinase resistant
Flucloxacillin
42
What is a 'true' penicillin allergy?
Immediate rash
Anaphylaxis
hives
43
What is considered mild allergy/may not be allergic? can penicillins be used?
Minor rash/small/not itchy/non confluent, rash develops after 72hrs
Do not withhold penciillin for serious infections
44
can penicillins be given intrathecally?
No - can cause encephalopathy /cerebral irritation
45
what penicillins are broad spectrum
Amoxicillin
ampicillin
46
What is a common issue/SE with broad spectrum abx
abx associated colitis
47
Why would you not give broad spectrum abx blindly for sore throats?
Can cause maculopapular rash if use in glandular fever (epstein barr)
48
Why is ampicillin not used as much
high resistance
49
Uses of ampicillin?
UTI, otitis media, acute COPD
50
What is a counselling point for ampicillin
Before food because absorption reduced by food
51
What is a side effect of amoxicillin? What is the max treatment duration because of this?
Cholestatic jaundice - treatment shouldn't really exceed 14days
52
What is a main use of benzylpenicillin pen G? and what route is it used?
Meningitis
| IV /parenteral only - not gastric acid stable and no gut absorption
53
What is phenoxymethylpenicillin used for
Resp tract infections in children e.g. strep throat, tonsillitis, sinusitis
oral
54
What indications does flucloxacillin have
Penicillin resistant staphycloccoi but NOT MRSA
- skin infections
- impetigo
- cellulitis
- diabetic foot/ulcers
55
name key side effects of flucloxacillin and when they present
Cholestatic jaundice and hepatitis = presenting up to 2 months after treatment
56
What are risk factors for developing cholestatic jaundice and hepatitis with use of flucloxacillin?
Increased age
| >14 days use
57
cautionary label for flucloxacillin
Take this medicine when your stomach is empty. This means an hour before food or 2 hours after food
58
What are 1st generation cephalosporins
CEFA
- cefalexin
- cefadroxil
- cefradine
59
What are 2nd generation cephalosporins
cefuroxime
| cefaclor d
60
What are 3rd generation cephalosporins
Contains T except cefixime
- Cefixime
- ceftriaxone
- ceftotaxime
- ceftazidine
61
What is the activity of 3rd gen cephalosporins
Greater activity against gram negative
| less active against positive e.g. s.aureus
62
Which cephaloxposin is active against pseudomonas
Ceftazidine
| and 4th generatiton Cefepimee
63
What is the dosing for ceftriaxone and what does it treat
OD (long half life)
- gonorohoea
- meningitis
- sepsis
64
which cephalosporin is active against MRSA
5th generation Ceftaroline
65
which cephalosporins is abx associated colitis more common with?
2nd and 3rd gen
66
What situations can cephalosporins be used in UTI?
pregnancy
| 2nd line
67
Are carbapenems active against pseudomonas?
Yes - imipenem and meropenem
| not active against MRSA or enterococcus
68
What are carbopenems used for?
Severe hospital acquired infections and polymicrobial infections e.g. sepsis, HAP, intra-abdominal infections, skin and soft tissue, complicated UTI
69
What is ertapenem used for?
Abdominal and gynaecological infections
CAP (but not against atypical resp pathogeens or penicillin resistant pneumoccoci)
(no pseudomonas)
70
What is the issue with imipenem
Partially inactivated in kidney by enzymatic activity - must be administered in combination with cilastatin (enzyme inhibitor to block renal metabolism)
71
Does meropenem have less seizure inducing potential?
yes
72
which antimalarials are OTC
malarone -atovaquone and proguanil
chloroquine and proguanil
mefloquine
doxycycline
73
What are the effects of mefloquine
neuropsychiatric reactions - psychosis, suicidal ideation and suicide
also insomnia, anxiety, confusion
- need to stop and seek immediate medical attention
Contraindicated in history of depression or convulsions
Also causes dizziness/balance off-caution in driving
74
if a journey requires 2 regimens for malaria prophylaxis what regimen is chosen
the one with the highest risk for whole journey
75
What is the length of time before travel when need to start chloroquine and proguanil
1 week before
76
what is the length of time before travel do treat with mefloquine for malaria prophylaxis and why
mefloquine stat 2-3 weeks before because of the risk of s/e e.g. neuropsychiatric - want to establish whether pt can tolerate
77
What is the length of time the patient starts taking doxycycline for malaria prophylaxis before travel
2-3 days - good for urgent/last min
78
What is the general length of time needed to take malaria prophylaxis after arriving home? what is the exception?
4 weeks after
| Except for malarone which is 1 week after
79
which patient groups would you advise against going to malaria countries
asplenic
| pregnant
80
Which antimalarials are avoided in epilepsy and what can be used
chloroquine
mefloquine
reduce seizures threshold
Use: doxycycline or malarone
81
If a pregnant pt needs to go to malarial area what is used
Chloroquine and proguanil
| plus 5mg folic acid with proguanil
82
What are the antimalarial options in renal impairment
doxycycline or mefloquine
| NOT proguanil, or malarone/chloro in <30
83
If a patient is on warfarin but needs malaria prophylaxis what is the protocol
starting on it 2-3 weeks before to establish INR changes and ensue INR is stable before departure
Monitor INR before initiation, 7 days after and after completion
84
What is a significant side effect of chloroquine
Ocular toxicity and eye problems
85
If a patient presents with illness within 3months-1year of travel to malarial country, what is the most appt action?
Illness=fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness
Refer- potential malaria
86
What is the standby emergency treatment of malaria e.g. if suspect that pt wont access medical care in 24hrs of fever onset?
Quinine-only if cannot access medical carer with written instructions
(note that a drug used for chemoprophylaxis should not be used for standby treatment for the same traveller)
