Infections- HIGH Flashcards
1
Q
What factors need to be considered when selecting antibacterials?
A
- Allergies
- Renal and hepatic function
- Immunocompromised?
- Severity of illness (e.g. life-threatening require IV admin.)
- Other medication
- Pregnant/breast-feeding
2
Q
When may IV admin. be suitable in a non-life-threatening infection?
A
- Nil-by-mouth patients e.g. swallow difficulties
- Vomiting
3
Q
What is phenoxymethylpenicillin used as prophylaxis for?
A
- Prevent recurrence of rheumatic fever
- Prevent streptococcal infection, pneumococcal infection in asplenia
4
Q
What is isoniazide +/- rifampicin used as prophylaxis for?
A
Prevent TB in susceptible patients
5
Q
What is IV gentamicin used as prophylaxis for?
A
Prevent infection in surgical procedures
6
Q
What infection is associated with broad-spectrum cephalosporins?
A
Antibiotic associated colitis (C. diff)
7
Q
When are anaphylaxis, urticaria and rash more common in patients?
A
Those with a history of atopic allergy e.g. bronchial asthma
8
Q
Common side effects of penicillins?
A
- Diarrhoea
- Hypersensitivity
9
Q
Which other antibiotics may allergic patients also react to due to similarity?
A
- Cephalosporins e.g. cephalexin
- Beta lactam antibiotics
10
Q
Is a rash always an allergic reaction?
A
No- a non-pruritic rash restricted to a small area or occurring > 72 hours after admin. is probably not allergic
11
Q
What is benzylpenicillin (penicillin G) indicated for?
Points to consider?
A
Indicated for throat infections, otitis media, cellulitis, meningococcal disease, septicaemia
- MUST be given IV/IM- inactivated by gastric acid (and bacterial beta-lactamases)
- May impair efficacy of oral contraceptives
12
Q
What is Phenoxymethylpenicillin (Penicillin V) indicated for?
Points to consider?
A
Indicated for RTIs in children, strep tonsillitis
- Should be given (orally) in divided doses (TDS/QDS) half an hour before meals
- Total daily dose usually 1-2g in divided doses
13
Q
What is flucloxacillin indicated for?
Points to consider?
MAX daily dose?
A
Indicated for otitis externa, cellulitis, osteomyelitis
- Acid stable and well absorbed from gut (can be oral or IV)
- Should NOT be used in hepatic dysfunction (can cause liver injury- DILI)
- Take 30 mins before food
- MAX: 500mg every 6 hrs
14
Q
What kind of infections is temocillin reserved for?
A
Infections caused by beta-lactamase-producing strains of Gram-negative bacteria
15
Q
What is ampicillin (broad spec) indicated for?
Points to consider?
MAX daily dose?
A
Indicated for chronic bronchitis, middle ear infections and UTIs
- Inactivated by penicillinases
- Less than half dose absorbed orally (take 30 mins before food)
- Consider resistance- do not use for hospital patients without checking sensitivity
- MAX 1g every 6 hours
16
Q
What is amoxicillin (broad spec) indicated for?
A
Indicated for oral infections, sinusitis, pharyngitis, bronchitis, pyelonephritis
- Better absorption than ampicillin
- MAX daily dose 1g every 8 hours
17
Q
What is co-amoxiclav indicated for?
Points to consider?
MAX daily dose?
A
Used to treat RTIs, UTIs and abdominal infection
- Amoxicillin + Clavulanic acid
- Active against beta-lactamase producing bacteria resistant to amoxicillin
- Cholestatic jaundice 6x greater with co-amoxiclav than amoxicillin
- MAX: one 500mg/125mg tab every 8 hrs
18
Q
What is piperacillin + tazobactam indicated for?
What is its brand name?
A
Indicated for hospital acquired pneumonia (HAP), septicaemia, complicated UTIs
- Brand: Tazocin
- Given by IV infusion
19
Q
What is clavulanic acid’s function?
A
It is a beta-lactamase inhibitor- protecting beta-lactam antibiotics from breakdown
20
Q
What is Ticarcillin + clavulanic acid indicated for?
What is its brand name
Points to consider?
A
Indicated for infections due to pseudomonas and proteus species
- Cholestatic jaundice associated with clavulanic acid
- Given by IV infusion
21
Q
Which generations of cephalosporins are good for unresponsive UTI or UTI in pregnancy?
A
First and second
22
Q
A
23
Q
What is cefaclor (Distaclor, Distaclor LA) indicated for?
Typical dosing schedules?
A
Indicated for pneumonia, lower UTI
- 250mg every 8 hrs (doubled in severe)
- Distaclor LA (375mg BD with food, double in pneumonia)
- Distaclor LA forte (500mg BD)
24
Q
What is cefalexin indicated for?
Typical dosing schedules?
A
Indicated for UTI prophylaxis, HAP
- 250mg every 6 hrs, or 500mg every 12 hrs
- 125mg nocte for UTI prophylaxis
25
What is cefuroxime indicated for?
Typical dosing schedule?
Indicated for haemophilus influenzae, RTI, pyelonephritis
500mg BD
26
What is ertapenem indicated for?
Community-acquired pneumonia (CAP)
27
What is meropenem indicated for?
Hospital-acquired septicaemia
28
What is imipenem indicated for?
Hospital-acquired septicaemia
29
Points to consider re macrolides?
SE etc?
* Similar spectrum to penicillin- alternative in penicillin allergy
* Caution in patients predisposed to QT interval prolongation
* S/E: GI upset
30
What is azithromycin indicated for?
Dosing schedule?
Indicated for RTI, otitis media, gonorrhoea and chlamydia
* 500mg OD for 3/7
* 1g single dose for gonorrhoea and chlamydia
31
What is clarithromycin (Klacid) indicated for?
Dosing schedule?
Points to consider?
Indicated for RTI, otitis media and H. Pylori (with PPI)
* CYP3A4 inhibitor
* 250-500mg BD for 7-14 days
* Klacid MR: one 500mg tab daily
32
What is erythromycin indicated for?
Dosing schedule?
Points to consider?
Indicated for RTI, pneumococcal infection, chlamydia and syphilis
* CYP3A4 inhibitor
* 1-2g daily in divided doses
* 250-500mg every 6 hrs (Alternatively 0.5-1g every 12 hrs)
33
Preferred macrolide with patient on warfarin?
Erythromycin preferred- greater risk of increased INR (bleeding risk)
34
Points to consider for tetracyclines?
* Broad spectrum
* May increase muscle weakness in patients with myasthenia gravis
* Antacids, milk, Ca, Mg, Fe, Zn, Al salts decrease absorption (take 1-2 hours before)
35
When are tetracyclines contraindicated?
* Pregnancy/BF- effects skeletal development and causes tooth discolouration
* < 12 y/o- deposits in teeth and bone causing staining & dental hypoplasia
36
S/E of tetracyclines?
* GI upsets, dysphagia, oesophageal irritation
* Hepatotoxicity
* Photosensitivity
To reduce oesophageal irritation, take whole with plenty of fluid, while sitting or standing
37
What is tetracycline indicated for?
Dosing schedule?
S/E?
Indicated for acne
* 500mg every 6-8 hrs
* S/E: skin discolouration
38
What is doxycycline indicated for?
Dosing schedule? MAX daily dose?
Indicated for sinusitis, malaria prophylaxis
* Longer duration of action than tetracycline or oxytetracycline- allows OD dosing
* 100mg day one, then 100mg daily
* MAX: 200mg daily
39
What is lymecycline indicated for?
Dosing schedule?
Indicated for acne
* 408mg daily for at least 8 weeks
40
What is minocycline (Minocin SA(MR)) indicated for?
Points to consider?
Dosing schedule?
indicated for acne (min. 6 weeks and max. 6 months)
* 100mg BD
* Minocin MR- 100mg OD for acne
* If no response after 6 months, discontinue and try other therapies
* Unlike other tetracyclines, absorption not impaired by food or milk
41
What is oxytetracycline indicated for?
Indicated for acne, rosacea
* MAX dose 500mg every 6 hrs
42
What are the S/E of aminoglycosides?
Where are they more common?
Nephrotoxicity and ototoxicity
* Dose related
* Elderly more susceptible to ototoxicity
* Most common in elderly & renal failure
43
How can aminoglycoside S/E be managed?
* Dose reduction may be required in elderly
* Monitor serum-concentration
* Do not give with ototoxic drugs i.e. cisplatin, furosemide
44
Monitoring requirements for aminoglycosides?
* Renal function before and during treatment
* Auditory and vestibular function tests during treatment
45
What is gentamicin indicated for?
Usually combined with...?
Points to consider?
Indicated for septicaemia, neonatal sepsis, CNS infection and HAP
* Usually given with a penicillin or metronidazole
* Loading & maintenance doses calculated by weight/renal function/serum concentrations
46
What is neomycin sulfate indicated for?
Used in bowel sterilisation prior to surgery
47
What is streptomycin indicated for?
What should peak and trough serum conc. be while monitoring?
Active against Mycobacterium tuberculosis- entirely reserved for TB
* One-hour ('peak') concentration should be 15-40mg/L
* Pre-dose ('trough') concentration should be < 5mg/L (less than 1mg/L in renal impairment or those > 50 y/o)
48
What is tobramycin indicated for?
Monitoring?
Points to consider?
Indicated for septicaemia, meningitis, HAP, UTI, Chronic Pseudomonas aeruginosa in cystic fibrosis
* Taken by IV or inhalation
* Measure lung function before and after treatment
* Monitor bronchospasm
49
What is chloramphenicol indicated for?
indicated for superficial eye infections, bacterial infection in otitis externa (topical)
Life-threatening infections, particularly those caused by Haemophilus influenzae (systemic use)
Typhoid (systemic use)
50
S/E for chloramphenicol?
* Serious haematological S/E i.e. aplastic anaemia when given systematically
* Chronic exposure has lead to bone marrow hyperplasia
51
Dosing for chloramphenicol drops and ointment?
* Drops: 1-2 drops applied to affected eyes up to 6 times daily
* Ointment: Apply 1cm ribbon 3-4 times daily
52
What is sodium fusidate (Fucidin) indicated for?
Penicillin-resistant staphylococci i.e. osteomyelitis, as it concentrates in bone
53
Points to consider for sodium fusidate?
* Fusidic acid salt- consider low sodium diet
* Narrow spectrum
* Contraindicated with statins!!- risk of rhabdomyolysis, discontinue statin treatment with systemic Fucidin. Advise patients seek medical aid if experiencing muscle weakness, pain or tenderness
54
Dosing schedule for fusidic acid
500mg every 8 hrs
55
What is daptomycin indicated for?
Complicated skin and soft tissue infections i.e. MRSA
56
Resistance to which other antibiotic initiates daptomycin use?
Vancomycin
57
S/E associated with daptomycin?
Muscle side effects:
* Myositis
* Weakness
* Myalgia
* Rhabdomyolysis
58
Monitoring requirements for daptomycin
Creatinine clearance before and during treatment
59
What is linezolid indicated for?
* Community acquired pneumonia (CAP)
* Skin/ soft tissue infections
* MRSA
60
Points to consider for linezolid?
* Resistance can develop in prolonged or under dosed treatment
* Only initiated in hospital setting
* MAX 28 days duration
61
S/E associated with linezolid?
* Diarrhoea
* Optic neuropathy
* Blood disorders
* Myelosuppression
62
Typical dosing schedule for linezolid?
600mg every 12 hours for 10-14 days
63
Monitoring requirements for linezolid?
Monitor for muscle S/E
FBCs weekly
* High risk patients i.e. pre-existing anaemia, granulocytopenia, thrombocytopenia, or patients receiving other medication that affect blood counts
64
Example of glycopeptide antibiotics
Vancomycin (Vanocin)
65
What are glycopeptide antibiotics e.g. vancomycin indicated for?
* Parenterally in treatment of endocarditis
* Orally for C. diff
66
What is rifaximin indicated for?
* Travellers diarrhoea
* Prevent hepatic encephalopathy
67
Typical dosing schedule for rifaximin?
550mg BD
68
What is co-trimoxazole? (Septrin)
Trimethoprim + Sulfamethoxazole (1:5)
69
What is co-trimoxazole indicated for?
* RTI
* UTI
70
S/E associated with co-trimoxazole?
S/E are rare but can be very serious, discontinue if the following occurs:
* Blood disorders
* Rash (including Stevens-Johnson syndrome or toxic epidermal necrolysis)
71
Typical dosing schedule for co-trimoxazole?
960mg every 12 hours
72
What is trimethoprim indicated for?
* UTI
* Chronic bronchitis
73
When should trimethoprim be avoided?
* Renal impairment
* Low folate status, or taking folate antagonist i.e. antiepileptic, proguanil
74
Where does trimethoprim concentrate?
The bladder
75
Can trimethoprim be taken during pregnancy?
Not in the first trimester- teratogenic risk during this period
76
Typical dosing schedule for trimethoprim acute infections
200mg BD
77
Typical dosing schedule for trimethoprim prophylaxis of infections
100mg ON
78
Counselling points for patients on trimethoprim
Recognising blood disorders i.e. fever, sore throat, rash, mouth ulcers
79
What class of antibiotic is clindamycin?
Lincosamide antibiotic
80
What is clindamycin indicated for?
Staphylococcal joint and bone infections i.e. osteomyelitis
81
When should clindamycin be discontinued?
Associated with antibiotic-associated colitis - discontinue if diarrhoea develops
82
Which medication's efficacy is affected by clindamycin?
Can reduce efficacy of oral contraceptives- take extra precaution during treatment i.e. barrier methods
83
Typical dosing schedule for clindamycin?
150-300mg every 6 hours
84
What are the treatment steps for anti-tuberculosis drugs?
Initial phase:
* 4 drugs, 2 months duration (rifampicin, isoniazid, pyrazinamide, ethambutol)
Continuation phase:
* 2 drugs, 4 months duration (isoniazid, rifampicin)
6 months treatment course
85
Which of the 4 anti-TB drugs are associated with liver toxicity?
How is this managed
* Pyrazinamide
* Rifampicin
* Isoniazid
Monitor before and during treatment
Advise patients on recognising liver symptoms e.g. jaundice, abdominal pain and swelling etc
86
What are the monitoring requirements for anti-TB drug regimen?
* Hepatic function- LFTs
* Renal function- eGFR + U&Es
* Visual acuity- before starting ethembutol
87
Common S/E of isoniazid?
* Peripheral neuropathy
* Hepatic disorders
88
Common S/E of pyrazinamide?
Hepatic disorders
89
How should patients be counselled to watch for hepatic disorders?
* Persistent nausea
* Vomiting
* Diarrhoea
* Malaise
* Jaundice
90
Common S/E and points to consider regarding rifampicin?
* Red colouration of the urine, sweat, sputum and tears
* Discolours soft lenses
* POTENT CYP INDUCER
* Take tabs at least 30 mins before meal or 2 hours after
* Reduces efficacy of hormonal activity
91
What is metronidazole indicated for?
* Trichomonal vaginitis
* Bacterial vaginitis
* Giardia Lambia
* C. diff
* Dental infections
Often the alternative to penicillins for oral infections
92
Usual dosing regimen and points to consider for metronidazole?
400mg every 8 hours
No alcohol during treatment
93
Common S/E of macrolides and points to consider?
S/E: GI upset, headache, dizziness
* Caution in epilepsy
* Can prolong QT interval
* Causes arthropathy in weight-bearing joints of growing children
* Tendon damage and rupture reported- contraindicated in tendon disorders and patients > 60
94
What is ciprofloxacin indicated for?
Points to consider?
RTI and UTI
May impair performance of skilled tasks, effects enhanced by alcohol
95
MAX dosing regimen for ciprofloxacin?
MAX: 750mg BD
96
Usual dosing regimen for levofloxacin?
500mg OD
97
Points to consider for moxifloxacin?
Contraindicated in patients at risk of QT prolongation
98
Knock-on effect of UTI in renal impairment?
Antibiotics excreted by the kidney can accumulate in kidney failure, leading to toxicity
99
Points to consider in UTI during pregnancy?
* UTI may be asymptomatic
* May require prompt treatment to prevent progression to acute kidney infection (pyelonephritis)
* Penicillins and cephalosporins are suitable, nitrofurantoin may be used
100
Cautions and S/E with nitrofurantoin?
Avoid in renal impairment
S/E: GI upset, anorexia
101
Dosing regimens for nitrofurantoin for acute uncomplicated infection, prophylaxis and using MacroBID
* Acute uncomplicated: 50mg every 6 hrs with food (100mg in severe)
* Prophylaxis: 100mg nocte
* MacroBID: 1 cap BD with food
102
What is fluconazole indicated for?
Vaginal candidiasis
Fungal meningitis
103
Points to consider for fluconazole
* Good penetration into CSF to treat fungal meningitis
* Excreted largely unchanged in the urine (can be used to treat candiduria)
* inhibits CYP2C9, CYP3A4, CYP2C19
Many interactions, avoid other meds metabolised by these enzymes that prolong QT interval
104
Dosing regimen for fluconazole in vaginal candidiasis?
150mg capsule single dose
105
Points to consider with itraconazole (Sporanox)
* Requires an acidic environment in the stomach for optimal absorption
* Associated with life threatening liver damage - discontinue if signs of hepatotoxicity
* Avoid in history of liver damage and always monitor LFTs
* Increased risk of heart failure due to CYP3A4 and p-glycoprotein inhibition
* Contraindicated in pregnancy (women of childbearing age must use contraception)
106
Dosing regimen for vulvovaginal candidiasis?
200mg BD for one day
107
Points to consider for posaconazole?
* Contraindicated with HMG-CoA reductase inhibitors e.g. amlodipine, atorvastatin
* CYP3A4 inhibitor
* Associated with hepatotoxicity and QT prolongation
Monitor LFTs
108
Points to consider for voriconazole (Vfend)
* CYP3A4 inhibitor
* Associated with hepatotoxicity and QT prolongation
PHOTOTOXICITY:
* Avoid intense/prolonged exposure to sunlight, sunbeds and direct sunlight
* Use high SPF and cover skin
* Seek medical attention if skin reaction (monitor for pre-malignant skin lesions, squamous cell carcinoma)
HEPATOTOXICITY:
* Associated with life-threatening liver damage
* Counsel patients on recognising symptoms of liver damage i.e. anorexia, GI upset, dark urine
109
What is amphotericin and what is it indicated for?
A polyene antifungal
* Used to treat systemic fungal infections
* Not absorbed by mouth, given IV
110
What is nystatin and what is it indicated for?
A polyene antifungal
Treat oral, oropharyngeal, perioral, candida skin infections
111
What is griseofulvin indicated for?
Points to consider?
Effective in widespread dermatophyte infection (e.g. tinea barbae, capitis, corporis, cruris, pedis, unguium) where topical therapy is not working
* Take after a high fat meal, for increased absorption and minimising GI distress
* Personal hygiene is important
* Reduces effectiveness of oral contraception, use barrier methods too
* Continue treatment for at least 2 weeks after all signs if infection clear
* CYP3A4 INDUCER
112
What is terbinafine indicated for?
Usual dosing regimen?
* Fungal nail infections
* Ringworm
250mg daily
* for 2-4 weeks (Tinea cruris)
* for 4 weeks (Tinea corporis)
* for 2-6 weeks (Tinea pedis)
* for 6 weeks-3 months (Onychomycosis- fungal nail infections)
113
Points to consider for HIV infection and treatment
* No cure- drugs slow progression, reduce complications and risk of transmission
* Drugs associated with severe S/E
* Optimal time to initiate treatment depends on CD4 cell count
* Antiretrovirals associated with metabolic S/E
* Fat redistribution
* Insulin resistance
* Dyslipidaemia
* Lipodystrophy syndrome
* Associated with osteonecrosis of the jaw
114
What is aciclovir indicated for?
What is the typical dosing regimen?
* Herpes simplex
* varicella zoster- chicken pox
800mg five times daily for 7/7 (omit night time dose
115
Which drugs are used to treat chronic Hep B?
* Adefovir
* Entecavir
* Telbivudine
116
Which drugs are used to treat chronic hepatitis C?
* Telaprevir
* Boceprevir
* Telbivudine
117
Which medications are used for influenza infection post-exposure prophylaxis?
* Oseltamivir (Tamiflu)
* Zamavir (Relenza)
118
Prophylaxis and treatment doses for Oseltamivir (Tamiflu)
Treatment: one 75mg tab BD for 10/7
Prophylaxis: one 75mg tab OD for 10/07
119
Prophylaxis and treatment doses for Zamavir (Relenza)
By which method is it administrated?
Treatment: 10mg BD for 10/7
Prophylaxis: 10mg OD for 10/7
Admin. by inhalation
120
What is falciparum malaria?
A form of malaria (malignant)
* Resistant to chloroquine in most parts of the world
* VERY dangerous in pregnancy
121
How can patients travelling to risk zones help prevent malaria?
* Permethrin-impregnated mosquito nets
* DEET 20-50% roll on, lotions and sprays for adults and children
* Apply DEET after sunscreen
* Wear long sleeves
122
For how long after travelling to a risk zone may an illness be potentially malaria?
1 year
123
Which patient group is particularly at risk of severe malaria?
Asplenic patients (no spleen)
124
Which antimalarials are not suitable in epilepsy?
Chloroquine and mefloquine
125
Points to consider in pregnancy regarding malaria?
* Avoid travelling to risk zones
* Doxycycline is contraindicated
* Prophylaxis is required in BF, as amount passed through milk are too variable for reliable protection
126
Dosing regimen, S/E and instructions for atovaquone + proguanil (Malarone) for malaria prophylaxis and treatment
Treatment: one tab daily for 3 days
Prophylaxis: one tab 1-2 days before, during and 1 week after
S/E: GI upset, headache, depression, appetite decrease
Take same time each day with milk food or drink
127
Points to consider for threadworm infections?
* All family members require treatment
* Hygiene measures are important to break auto-infection cycle
* Only live for 6 weeks- ova must be swallowed and exposed to digestive juices
128
What hygiene measures must be taken in threadworm infection
* Wash hands and scrub nails before meals and after toilet
* Take a bath in morning to remove ova laid overnight
129
What is the drug of choice for threadworm infections?
Mebendazole (Vermox)
130
Dosing regimen, S/E for mebendazole for threadworm infection
Points to consider?
Dose: 100mg BD for 3/7
S/E: Abdominal pain, flatulence
Dose depends on type of worm
131
List of antibiotics to avoid in pregnancy
* Metronidazole
* Macrolides
* Quinolones
* Tetracyclines
132
List of antibiotics to avoid in breast feeding
* Quinolones
* Tetracyclines
