Infection Flashcards
(116 cards)
1
Q
What types of antibiotics are safest to use in pregnancy?
A
Penicillins and cephalosporins
2
Q
Which antibiotics should be avoided in pregnancy?
A
Trimethoprim (folate antagonist - teratogenic)
Quinolones
Diaminopyrimidines (eg trimethoprim)
Tetracycline (dental discolouration)
3
Q
Which is NOT a notifiable disease?
- TB
- Measles
- Food poisoning
- Endocarditis
- Meningitis
A
Endocarditis
The rest should be notified by drs to the Proper Officer of local authority
4
Q
Name the aminoglycosides
A
Gentamicin, amikacin, neomycin, streptomycin, tobramycin
5
Q
What is the mode of action of aminoglycosides?
A
Irreversibly bind to ribosomes and inhibit protein synthesis
6
Q
‘Aminoglycosides have mainly got gram +ve action’
True or false
A
False - they are active against some gram +ve organisms and many gram -ve
7
Q
Which condition are aminoglycosides contra-indicated in?
A
Myasthenia gravis - impair neuromuscular transmission
8
Q
Which aminoglycoside is NOT given IV?
A
Neomycin
Rest must be IV as not absorbed by gut
9
Q
Monitoring for aminoglycosides?
A
- Renal function - can be nephrotoxic especially in renal impairment
- Auditory function - can cause irreversible ototoxicity
- Serum concentrations esp in elderly/pregnant patients
10
Q
‘When dosing aminoglycosides for obese patients ideal body weight should ALWAYS be used’
True or false?
A
True
11
Q
‘Gentamicin is inactive against anaerobes’
True or false?
A
True, has good gram -ve activity
12
Q
When should gentamicin levels be taken in multiple-daily dosing?
A
- At peak concentration (1 hour post-dose) and levels should be 5-10mg/L
- At trough conc (pre-dose) and levels should be <2mg/L
13
Q
What are key warning signs for patients taking gentamicin?
A
- Dehydration
- Ototoxicity
- Nephrotoxicity
14
Q
Name some antibiotics associated with ototoxicity?
A
- Aminoglycosides (inc gentamicin)
- Glycopeptides (inc teicoplanin + vancomycin)
15
Q
How many generations of cephalosporins are there?
A
5 generations 1st - eg cefalexin 2nd - eg cefuroxime 3rd - eg cefotaxime 4th - eg cefepime 5th - eg ceftobiprole
16
Q
Some indications for cephalosporins?
A
UTI, gonorrhoea, pneumonia, meningitis
17
Q
What is the main side effect of cephalosporins?
A
Hypersensitivity
0.5-6% of patients with penicillin will also be allergic
c/i in patients with IMMEDIATE HYPERSENSITIVITY to penicillin
18
Q
How are cephalosporins excreted?
A
Renally
Reduce doses in renal imp.
19
Q
Which cephalosporin is poorly absorbed and must be taken with food?
A
Cefuroxime
20
Q
‘Carbapenems are narrow spec antibiotics’
True or false?
A
False - they are broad spectrum
Active against gram +ve, gram -ve and anaerobes
21
Q
Some indications for carbapenems?
A
Severe hospital-acquired infections
Complicated UTIs
22
Q
Why is ertapenem cautioned in epilepsy?
A
Has seizure-inducing potential and can cause CNS disorders
23
Q
‘Carbapenems are renally excreted’
True or false?
A
True
24
Q
Name some glycopeptides?
A
Vancomycin, teicoplanin, telavancin
25
Some indications for glycopeptides?
MRSA, C diff, endocarditis, surgical prophylaxis if high risk of MRSA
26
Which is NOT a side effect of glycopeptides?
- Steven Johnsons syndrome
- Blood disorders
- Flushing
- Hypertension
- Ototoxicity
HTN
27
Name contra-indications for glycopeptides?
- Elderly
| - History of auditory problems
28
Which antibiotic is associated with red man syndrome?
Vancomycin
| signs - flushing of upper body, angioedema, hypotension
29
How is serum conc of vancomycin measured?
Trough level on second day of treatment
Should be 10-15mg/L
- also monitor renal + hepatic function, auditory func and blood counts
30
What are some warning signs for patients on Vancomycin?
- ototoxicity (inc vertigo, dizziness + tinnitus, avoid with other drugs causing this eg loop diuretics, aminoglycosides)
- flushing
- blood disorders (inc sore throat, mouth ulcers, unexplained bleeding)
- nephrotoxicity
- skin disorders
- anaphylaxis + hypotension (if administered too quickly)
31
What is the minimum rate for a 500g dose of vancomycin?
Not exceed 10mg/min
32
Which antibiotic should be discontinued IMMEDIATELY if diarrhoea develops?
Clindamycin
Risk of fatal antibiotic-associated colitis
Also C/I in existing diarrhoea
33
'Clindamyin is well concentrated in bones and excreted in bile + urine'
True or false
True
| Indicated in staphylococcal bone + joint infections
34
What patient counselling is required for clindamycin?
- Take capsule with a full glass of water
| - report any diarrhoea immediately
35
Why is clindamycin cautioned in middle aged/elderly women?
- colitis can be more common
| - especially following surgery
36
'Macrolides have a similar action to penicillins'
| True or false?
True - and similar spectrum
| Often an alternative in penicillin allergy
37
Which macrolide is most likely to cause GI disturbances?
Erythromycin
38
Some indications of macrolides?
Respiratory tract infections, chlamydia, skin infections
39
When are macrolides cautioned?
Conditions that pre-dispose QT prolongation eg, electrolyte disturbances, other drug with risk of QT prolongation
40
Azithromycin may be sold OTC, for what indications and under what conditions?
Sold for confirmed + asymptomatic chlamydia infection
Single dose of 1g
Over 16 years
41
Which enzyme do macrolides inhibit?
CYP3A4
| Esp clarithromycin + erythromycin
42
Some drugs that interact with clarithromycin + erythromycin?
- statins - risk of rhabdomylosis
- corticosteroids - risk of cushings syndrome
- CCBs - risk of hypotension/QT prolongation
- carbamazepine
- warfarin - increased anticoagulation
- PPIs - increased gastric pH
- Benzodiazepines - excess CNS depression
43
Which type of bacteria does metronidazole have a high activity against?
Anaerobic
44
Some indications of metronidazole?
- anaerobic infections
- oral infections
- leg ulcers
- pressure sores
- H pylori
45
Which antibiotic is the preferred treatment for tetanus?
Metronidazole
46
Why is metronidazole not recommended in breast feeding?
Can give milk a bitter taste
47
Patient counselling for metronidazole?
- Do not drink alcohol
| - Take with food
48
Which antibiotics MUST be taken with food?
- Metronidazole
- Doxycycline
- Cefuroxime
- Nitrofurantoin
49
What route should metronidazole be given by?
Orally
Well absorbed orally, IV reserved for severe infections
Also effective rectally/vaginally
50
How do penicillins work?
Inhibit bacterial cell wall synthesis by preventing peptidoglycan cross-linking
51
Caution for penicillin treatment?
History of allergy
1 - 10% people have allergic reactions following exposure
<0.05% patients have anaphylaxis
52
Which patients are at risk of immediate hypersensitivity to penicillins?
- patients with atopic allergy eg, asthma, eczema, hay fever
| - patients with a history of rash/hives/anaphylaxis IMMEDIATELY after penicillin administration
53
Which other antibiotics should be avoided in patients with a history of penicillin hypersensitivity?
Cephalosporins
| Other beta-lactams
54
Some indications for penicillins?
Oral infections, cellulitis, otitis media, respiratory tract infections, pneumonia, meningitis
55
Some side effects of penicillins?
Maculopapular rash, antibiotic-associated colitis, diarrhoea (esp broad spec), CNS toxicity (in high doses/renal imp)
56
Does metronidazole require a dose reduction in renal impairment?
No
57
What risk is associated with clavulanic acid (eg in co-amoxiclav)?
Risk of cholestatic jaundice
- more common in men or patients >65
- rare in children
- jaundice usually self-limiting
- max treatment 14 days
58
Safety warning associated with flucloxacillin?
Risk of hepatic disorders - cholestatic jaundice and hepatitis
- Can occur rarely up to 2/12 after fluclox stopped
- Higher risk with increased age or treatment over 2 weeks
- Do not use if history of hepatic dysfunction or impairment
59
Name some quinolone antibiotics?
Ciprofloxacin, levofloxacin, moxifloxacin, ofloxacin, norfloxacin
60
'Ciprofloxacin is commonly used to treat MRSA'
| True or false?
FALSE
| Many staphylococci are resistant to quinolones and should be avoided in MRSA infection
61
Two safety warnings associated with quinolones?
- risk of convulsions
| - risk of tendon damage
62
Why should quinolones not be taken at the same time as NSAIDs?
Can induce convulsions
63
What are some risk factors for tendon damage meaning quinolones should be used with caution?
- age >60
- use of corticosteroids
- history of tendon disorders
64
Why should quinolones be avoided in children?
Risk of arthropathy (joint disease) seen in animals
65
Cautions for use of quinolones?
- conditions with risk of seizures
- QT prolongation (risk factors include HF, MI, bradycardia, electrolyte imbalance)
- Photosensitivity (avoid sunlight exposure)
- diabetes (can affect blood glucose)
66
Side effects of quinolones?
GI disturbance, headache/dizziness, QT prolongation, skin reactions, depression/suicidal tendencies (discontinue drug if any psychiatric/neurological reactions occur)
67
Patient counselling for quinolones?
- may impair performance of skilled tasks eg driving
- should be taken on an empty stomach (cipro + levo)
- do not take with indigestion remedies, iron or zinc (or milk with cipro)
68
Name a contra-indication for Trimethoprim?
Blood dyscrasias
Cautioned in the elderly as higher risk of blood disorders
On long term therapy monitor blood counts
69
Which patient counselling is required for trimethoprim/co-trimoxazole?
Risk of blood disorders - report any signs eg, sore throat, rash, bruising, bleeding
70
Why should trimethoprim/co-trimoxazole be avoided in pregnancy?
Folate antagonist - can be teratogenic especially in the first trimester
71
Can trimethoprim be used in renal impairment?
No - reduce dose <30 and avoid <15
72
Which tetracycline has the broadest spectrum?
Minocycline
| But all are broad spec antibiotics
73
Some indications of tetracyclines?
Chlamydia, rickettsia, acne, rosacea, respiratory infections
74
Why are tetracyclines contra-indicated in children under 12?
Can bind to calcium in bones and teeth and cause discolouration
Also cannot be used in pregnancy/breast feeding
75
Which tetracycline should be taken with food?
Doxycycline
76
Why would you be concerned if a patient taking tetracycline complained of a headached and vision changes?
Risk of intracranial hypertension
77
Which antibiotics should be avoided in myasthenia gravis?
- Aminoglycosides (eg gentamicin, cause impaired neuromuscular transmission)
- Tetracyclines (can increase muscle weakness)
78
What counselling should be given to patients who are prescribed tetracyclines?
- Risk of photosensitivity, avoid excess sunlight exposure
- Taking with antacids, and some elements such as Ca, Zn, Fe can decrease absorbtion
- Should be swallowed whole with plenty of fluid while sitting/standing upright to avoid irritation of the jaw and throat
79
Which tetracyclines should NOT be taken with milk?
oxytetracycline, tetracycline, demeclocycline
80
How is doxycycline used for malaria prevention?
- 100mg OD
| - Take 1-2 days before entering endemic area and continue for 4 weeks after leaving
81
What is in co-trimoxazole?
Trimethoprim + sulfamethoxazole
82
Which antibiotics should be taken on an empty stomach?
- Azithromycin caps
- Phenoxymethylpenicillin (pen v)
- Flucloxacillin
- Tetracycline
83
Which antibiotic requires plasma creatinine kinase to be measured as there is a risk of myopathy?
Daptomycin
84
Why is chloramphenicol reserved for 'life threatening' infections in systemic use?
Associated with serious haematological side effects
85
Why should chloramphenicol be avoided in pregnancy and breast feeding?
Risk of grey baby syndrome
86
'Linezolid has a role in treating MRSA + VRE'
| True or false?
True
| Only active against gram +ve bacteria
87
Which monitoring is required with linezolid?
- weekly FBC - risk of haematpoeitic disorders
| - signs of visual impairment - risk of optic neuropathy
88
Which foods should be avoided with linezolid?
MAOI - avoid foods rich in tyramine
| eg, bovril, marmite, mature cheese, salami etc
89
Why is linezolid cautioned in the elderly?
High risk of blood disorders
90
Why is linezolid cautioned in uncontrolled hypertension?
Can cause hypertension
91
How do you treat TB?
```
Initial phase (2 months):
Rifampicin, Isoniazid, Pyrazinamide + Ethambutol
```
```
Continuous phase (4 months):
Rifampicin and isoniazid
```
92
Can you give TB treatment to a pregnant/breast feeding patient?
Yes
93
Side effects of TB drugs?
Rifampicin - liver toxicity, discolouration of bodily fluids
Isoniazid - liver toxicity, peripheral neuropathy
Pyrazinamide - liver toxicity
Ethambutol - ocular toxicity
94
What is pyridoxine and why must it be given with isoniazid?
Vitamin B6
| For prophylaxis of peripheral neuropathy
95
Where does the antibacterial Nitrofurantoin act?
Bacteriacidal in the renal tissue and through the urinary tract
96
What colour can nitrofurantoin turn urine?
Yellow/brown
97
What is the renal dosing for nitrofurantoin?
Avoid if eGFR <45ml/min
98
Why is nitrofurantoin cautioned in hepatic imp?
Risk of cholestatic jaundice + hepatitis
99
What is amphotericin B?
A polyene antifungal used for severe/systemic fungal infections
100
Why should a test dose be given before administering amphotericin B?
Toxicity and anaphylaxis is common
Give test dose and observe patient for 30 mins
Some acute ADRs may need prophylactic antipyretics or hydrocortisone
101
Under which conditions can fluconazole be sold to the public?
For treatment for vaginal candidiasis and associated candidal balanitis (penile thrush)
Age 16-60
Single dose of 150mg
102
Name some triazole antifungals?
Fluconazole, itraconazole, posaconazole
103
What safety warning is associated with itraconazole?
Risk of heart failure
- do not give to patients at high risk of HF including: older adults, pts with cardiac disease, chronic lung disease, history of HF or negatively inotropic drugs
Rare risk of life-threatening hepatotoxicity
- monitor LFTs in prolonged treatment
- patients should seek medical advice if signs of hepatotoxicity appear inc dark urine, jaundice, abdo pain, N+V
104
Why should patients taking voriconazole be issued with an alert card?
```
1. Risk of hepatotoxicity
seek immediate medical attention if signs of liver dysfunction
2. Phototoxicity
Avoid excess sun exposure
seek medical attention for sunburn
monitor for signs of malignancy on skin
```
105
What are the signs of threadworm?
- Itching around anus/vagina
- weight loss
- sleep disturbance
106
How should threadworm be treated?
Mebendazole 100mg single dose
- with good hygiene measures
- licensed for age 2+ OTC, should treat whole household
- if reinfection is suspected a second dose may be taken after 2 weeks
107
What should be recommended for bite protection for travellers at risk of malaria?
- Wear longs after dusk
- Use mosquito nets with permethrin
- Use DEET 20-50%
108
What advice should be given to travellers using DEET at the same time as sunscreen?
DEET reduces SPF
| Apply DEET after sunscreen
109
How is malaria prophylaxis given?
```
Before entering endemic area:
- usually start 1 week prior
- doxycycline + malarone 1-2 days prior
- mefloquine 2-3 weeks prior
After leaving endemic area:
- Usually continue for 4 weeks
- Malarone continued for one week
```
110
What is in Malarone?
Atovaquone + proguanil
111
Which anti-malarials should not be used in epilepsy?
Mefloquine + chloroquine - risk of neuropsychiatric reactions
112
Which anti-malarials should be used in pregnancy?
Proguanil with folic acid supplements
| AVOID malarone
113
Which antimalarial has a risk of ocular toxicity?
Chloroquine
| low risk at doses below 4mg/kg
114
What is the major side effect associated with mefloquine?
Neuropsychiatric reactions
- C/I in history of psychiatric disorders including depression
- Common: abnormal dreams, insomnia, depression, anxiety
- Long half life so effects may continue for months following discontinuation
- psychiatric symptoms can be a sign or more serious events, discontinue treatment
115
What is quinine used for?
Treatment of malaria and nocturnal leg cramps
116
Why is quinine cautioned in cardiac disease?
Risk of QT prolongation
