Chapter 5: Infection Flashcards
Name the antibiotics in the aminoglycoside class
Amikacin Gentamicin Neomycin Streptomycin Tobramycin
What aminoglycosides are active against Pseudomonas and what one is the treatment of choice?
Gentamicin - treatment of choice
Amikacin
Tobramycin - usually via inhalation in CF
What aminoglycoside is active against TB?
Streptomycin
mainly reserved for this indication
Can aminoglycosides be given orally?
No- destroyed by the gut so must be given via injection
Is gentamicin a broad or narrow antibiotic?
What strains does it have poor activity against?
Broad but it is inactive against anaerobes and poor activity against haemolytic streptococci and pneumococci
Very good for gram negative organisms
Which aminoglycoside is used for encocarditis?
If it is resistant to this, what is an alternative aminoglycoside?
Gentamicin plus another antibiotic
Streptomycin is an alternative if resistant to gentamicin
Are aminoglycosides more active against gram positive or gram negative?
Gram negative but are broad
Can neomycin be given IV?
No
too toxic
Can only be used for skin/mucous membrane infections… However BNF states the cream is less suitable for prescribing
(Can also be used to reduce the bacterial population of the colon prior to bowel surgery or in hepatic impairment)
What is the problem with using aminoglycosides in myasthenia gravis?
Contraindicated
May impair neuromuscular transmission
What antibiotics can be used for prophylaxis in rheumatic fever?
Pen V or sulfadiazine
What anitbiotics can be used for prevention of secondary case of menincoccal meningitis?
Ciprofloxacin or rifampicin
Or IM ceftriaxone (unlicensed)
What antibiotic can be used for prevention of secondary infection for Group A strep?
Pen V
What antibiotic can be used for prevention of secondary infection in Influenza Type B?
Rifampicin
What antibiotic can be used for prevention of secondary cases of diphtheria in non-immune patients?
Erythromycin
What is pertussis?
Whooping cough
What antibiotic is used for prophylaxis of pertussis (whooping cough)?
Clarithromycin
What antibiotic is used post splenectomy or in patients with sickle cell disease for prevention of pneumococcal infection?
Pen V
Erythromycin is penicillin allergic
What antibacterial prophylaxis/treatment is used in animal and human bites?
If the patient is penicillin allergic, what should be used instead?
Co-amox
If penicillin allergic: Doxycycline and metronidazole
Up to 5 days and give tetanus jab
What antibacterial prophylaxis do you use in hip and knee replacement?
Single dose IV cefuroxime/flucloxacillin
Add in gent
What antibacterial prophylaxis do you use in high lower limb amputation?
Use i/v co-amoxiclav alone or i/v cefuroxime + i/v metronidazole
What antibacterial prophylaxis do you use in caesarean section?
Single dose cefuroxime
What is 1st line for aspergillosis?
What is 2nd line if this cannot be used?
Voriconazole
Liposomal amphotericin
If a patient with aspergillosis is intolerant/refractory to voriconazole and liposomal amphotericin, what other antifungals can be used?
Caspofungin
Itraconazole
What systemic antifungal is used in vaginal candidiasis?
For resistant organisms, what can be used?
Fluconazole
Itraconazole as an alternative
What is micafungin licensed for?
Invasive candidiasis
Oesophageal candidiasis
Prophylaxis of candidiasis in patients undergoing haematopoietic stem cell transplantation
Cryptococcal meningitis, a fungal infection, is especially common in which group of immunocompromised patients?
How is this treated?
HIV positive
IV amphotericin followed by PO fluconazole
What is tinea capitis?
Fungal infection (ringworm) of scalp
What is tinea pedis?
Athlete’s foot
How do you treat tinea captis?
Systemically
Griseofulvin
Can also used an additional topical application
True or false:
In fungal nail infections, topical therapy is more effective than systemic
False
Systemic is more effective
Is fluconazole active against Aspergillus?
No
Is caspofungin effective against CNS fungal infections?
No
What is the advantage of lipid amphotericin formulations over conventional amphotericin?
Significantly less toxic and are recommended when the conventional formulation of amphotericin is contra-indicated because of toxicity, especially nephrotoxicity or when response to conventional amphotericin is inadequate
However, more expensive
What are echinocandin antifungals active against? (Caspofungin, micafungin)
Aspergillus and Candida
Not active against CNS fungal infections
What can be used for MRSA?
Glycopeptides mainly:
Teicoplanin
Vancomycin
Alternatives:
Tigecyline
Daptomycin
Linezolid (if glycopeptide unsuitable)
Tetracyclines can be used for skin or soft tissue infections or UTI caused by MRSA
Clindamycin can be used for bone and joint MRSA infections
Are carbapenems useful against MRSA?
No
Do carbapenems have good activity against pseudomonas? What is the exception to this?
Yes apart from ertapenem
Why does imipenem have to be administered with cilastatin?
Imipenem is partially inactivated in the kidney by enzymatic activity and is therefore administered in combination with cilastatin, a specific enzyme inhibitor, which blocks its renal metabolism
If meningitis is suspected, what antibiotic should be given before being transferred to hospital (as long as this doesn’t delay treatment)?
What would be an alternative?
IV benpen
Cefotaxime if penicillin allergic / chloramphenicol if history of immediate hypersensitivity to penicillin and cephalosporins
When would you use dexamethasone in meningitis?
In what situations would you avoid this?
Particularly in pneumococcal meningitis in adults, either before starting antibacterial therapy or within 12 hours of starting
Avoid using dex in septic shock, meningococcal septicaemia, immunocompromised, or meningitis following surgery
What is the recommended antibiotic therapy for children 3 months - adults 50 years in meningitis if the cause is unknown?
What is the suggested duration of treatment?
Cefotaxime or ceftriaxone
Consider adding vancomycin
10 days
What is the recommended antibiotic therapy for adults over 50 years in meningitis if the cause is unknown?
What is the suggested duration of treatment?
Cefotaxime or ceftriaxone
AND amoxicillin or ampicillin
Consider adding vanc
10 days
What is the recommended antibacterial therapy for meningitis caused by meningococci (neisseria)?
What would be an alternative if not suitable?
What is the suggested duration of treatment?
Benpen
Or cefotaxime/ceftriaxone
Chloramphenicol is an alternative if history of immediate hypersensitivity to penicillins or cephalosporins
7 days
What bacteria can be the cause of meningitis?
Meningococcal (neisseria)
Pneumococcal
Haemophilus influenzae
Listeria
What is the recommended antibacterial therapy for meningitis caused by pneumococcal?
If the organism if penicillin and cephalosporin resistant, what can be added?
What is the suggested duration of treatment?
Cefotaxime or ceftriaxone
Consider adding dex before first dose or within 12 hours of starting antibacterial therapy
If penicillin sensitive, change to benpen
If penicillin and cephalosporin resistant, vancomycin and rifampicin can be added
14 days
What is the recommended antibacterial therapy for meningitis caused by Haemophilus influenzae?
What is the suggested duration of treatment?
Cefotaxime or ceftriaxone
Consider adding dex before first dose or within 12 hours of starting antibacterial therapy
10 days
What is the recommended antibacterial therapy for meningitis caused by Listeria?
What is the suggested duration of treatment?
If history of immediate penicillin hypersensitivity, what could be an alternative?
Amoxicillin/ampicillin
AND gentamicin
21 days - can consider stopping gentamicin after 7 days
Alternative- co-trimoxazole for 21 days
How should the following be managed:
Patients presenting with sinusitis symptoms of 10 days or less
Paracetamol, ibuprofen, nasal saline
Antibiotics not usually required
How should the following be managed:
Patients presenting with sinusitis symptoms of 10 days or more
Could be considered for treatment with a high-dose nasal corticosteroid, such as mometasone furoate [unlicensed use] or fluticasone [unlicensed use] for 14 days. Supply of a back-up antibiotic prescription could be considered and used if symptoms do not improve within 7 days, or if they worsen rapidly or significantly.
In what situations would you offer antibiotics for sinusitis?
Should only be offered to patients with acute sinusitis who are systemically very unwell, have signs and symptoms of a more serious illness
Or if bacterial sinusitis is suspected
How should the following be managed:
Patients presenting with sinusitis symptoms of 10 days or more
Could be considered for treatment with a high-dose nasal corticosteroid, such as mometasone furoate [unlicensed use] or fluticasone [unlicensed use] for 14 days. Supply of a back-up antibiotic prescription could be considered and used if symptoms do not improve within 7 days, or if they worsen rapidly or significantly.
What is 1st and 2nd line in a non-penicillin allergic sinusitis patient if antibiotics are indicated?
1st line- Pen V
2nd line- Co-amox
especially if more serious illness
What is 1st line in a penicillin allergic sinusitis patient if antibiotics are indicated?
Doxycycline or clarithyromycin
What is 1st line in a penicillin allergic sinusitis PREGNANT patient if antibiotics are indicated?
Erythromycin
What antibiotic can be used in a pregnant UTI patient?
Cefalexin
If antibiotics are clinically appropriate, what would be used for otitis externa?
What if the patient is penicillin allergic?
Flucloxacillin
Clarithromycin
If antibiotics are clinically appropriate, what would be used for otitis media?
What if the patient is penicillin allergic?
Amoxicillin (or co-amox as second line)
Clarithromycin
Otitis media is most common in which age group?
Children
What antibiotics are likely to cause C.Diff?
Clindamycin
Penicillins
Cephalosporins
Fluoroquinolones
What 3 antibiotics can be used in C.Diff?
Vancomycin
Metronidazole
Fidaxomicin
For first episode of mild-moderate C.Diff, what should be used and for how long?
Oral metronidazole for 10-14 days
For second/subsequent C.Diff infection not responding to metronidazole, what can be used and for how long?
Oral vancomycin
Fidaxomicin can be used for severe infection
10-14 days
What antibiotic is used for bacterial vaginosis and how long for?
Metronidazole 5-7 days
What antibiotics cover chlamydia?
Azithromycin (single dose)
Doxycycline
Erythromycin
What would you use to treat gonorrhoea?
If the IM route is not possible, what would you use instead?
Single dose
Azithromycin and IM ceftriaxone
Cefixime instead (unlicensed)
What is the recommended length of treatment for osteomyelitis?
6 weeks
Osteomyelitis and septic arthritis antibiotic choice:
- First line
- If penicillin allergic
- If MRSA suspected
- Flucloxacillin
- Clindamycin
- Vancomycin or teicoplanin
What penicillins can you use for oral infections e.g. dental?
Pen V
Amoxicillin
However these are not effective against bacteria that produces beta lactamases
Co-amox can be used in severe cases
What is the drug of choice for acute ulcerative gingivitis?
Metronidazole
Is haemophilus influenzae a bacteria or a virus?
Bacteria
What is the recommended therapy for Haemophilus influenzae?
Cefotaxime or ceftriaxone
What antibiotics do you use to treat an acute exacerbation of chronic bronchitis and how long for?
Amoxicillin or a tetracycline for 5 days
What antibiotic therapy is recommended in low severity CAP and how long for?
What would be alternatives?
Amoxicillin
Alternatives= doxycycline, clarithromycin
7 days (if infection caused by staph, it would be 14-21 days)
What antibiotic therapy is recommended in moderate severity CAP and how long for?
Amoxicillin AND clarithromycin
Or doxycycline alone
7 days
What antibiotic therapy is recommended in high severity CAP and how long for?
Benpen AND clarithromycin/doxycycline
7-10 days
If MRSA suspected, add teic/vanc
For life-threatening CAP, what would be the recommended treatment and how long for?
If the patient was penicillin allergic, what would be the alternative?
Co-amox + clarithromycin
7-10 days
Alternative to co-amox would be cefuroxime or ceftriaxone
In CAP, the usual treatment duration is 7-10 days. When would you extend this to 14-21 days?
If staphylococci suspected
If MSRA was suspected in CAP, what would you add on to the treatment?
Teic/vanc
What are the main organisms that cause pneumonia?
Streptococcus pneumoniae Haemophilus influenzae Chlamydia pneumoniae Mycoplasma pneumoniae Legionella pneumophila
What would you use to treat pneumonia caused by chlamydial/mycoplasma?
Doxycycline
What is the difference between early onset vs late onset HAP (in terms of days in hospital)?
Early onset = less than 5 days admission to hospital
Late onset = more than 5 days after admission to hospital
How do you treat early onset HAP?
Co-amox or cefuroxime
How do you treat late onset HAP?
Antipseudomonal penicillin e.g. Pip Taz
OR
Broad spectrum cephalosporin e.g. ceftazidime
OR
Quinolone e.g. ciprofloxacin
MRSA- add vanc
What would you use to treat a small area of impetigo?
Fusidic acid
What would you use to treat a widespread infection of impetigo?
If penicillin allergic, what would be an alternative?
Oral flucloxacillin
Clarithromycin
What would you use to treat cellulitis?
If penicillin allergic, what can be used?
High dose flucloxacillin
Clindamycin/clarithromycin
What antibiotic would you use for mastitis during breastfeeding?
What if penicillin allergic?
Flucloxacillin
Erythromycin
10-14 days
What are the side effects of aminoglycosides?
Hearing impairment (ototoxicity - patients should report tinnitus, hearing loss, vertigo)
Nephrotoxicity
May impair muscle transmission-c/i in myasthenia gravis
What is the risk of aminoglycosides to the infant in pregnancy?
Risk of auditory or vestibular nerve damage
What is a possible problem with carbapenems that means it is cautioned in CNS disorders?
Seizure inducing potential
Also increased risk of seizures if renal impairment is present
Should you give carbapenems if there is a history of immediate hypersensitivity to penicillins?
No
True or false:
Cephalosporins penetrate the meninges poorly unless they are inflamed
True
What are some common side effects of cephalosporins?
Abdo pain
Eosoniphilia
Thrombocytopenia
Should you give cephalosporins if there is a history of penicillin allergy?
Used in caution
But should not be given if there is immediate hypersensitivity
What are the glycopeptide antibiotics?
Dalbavancin
Teicoplanin
Telavancin
Vancomycin
Which of the following antibiotics has a lower incidence of nephrotoxicity:
Teicoplanin
Vancomycin
Teicoplanin
What drugs are associated with red man syndrome?
Glycopeptides
Teicoplanin
Vancomycin
What is the main advice to give to patients on clindamycin and should stop taking if this happens?
Diarrhoea
Stop and contact doctor
What are the cautions in macrolides?
QT prolongation
and electrolyte disturbances
Amoxicillin can cause an increased risk of erythematous rash in what conditions?
Acute lymphocytic leukaemia
Chronic lymphocytic leukaemia
CMV
Glandular fever
Why should you maintain adequate hydration with high doses of IV amoxicillin?
Risk of crystalluria
Especially in renal impairment
What is the dose of amoxicillin in susceptible infection for a child 1-11 months?
125mg TDS
increased up to 30mg/kg TDS if needed
What is the dose of amoxicillin in susceptible infection for a child 1-4 years?
250mg TDS
increased up to 30mg/kg TDS if needed
What is the dose of amoxicillin in susceptible infection for a child 5-11 years?
500mg TDS
increased up to 30mg/kg TDS if needed
What is the dose of amoxicillin in susceptible infection for a child 12-17 years?
500mg TDS
Increased up to 1g TDS if needed
What is the dose of amoxicillin in susceptible infection for an adult?
500mg TDS
What is the MHRA warning surrounding flucloxacillin?
Cholestatic jaundice and hepatitis
What is a side effect of oral amoxicillin and co-amox in terms of colouring the patient’s tongue?
Black hairy tongue
Ciprofloxacin is a type of what antibiotic?
Quinolone
What is the important safety information regarding fluoroquinolones?
May induce convulsions in patients with or without a history of convulsions; taking NSAIDs at the same time may also induce them.
Tendon damage (including rupture) has been reported rarely in patients receiving quinolones. Tendon rupture may occur within 48 hours of starting treatment
Small increased risk of aortic aneurysm and dissection
Should quinolones be used in MRSA?
No
What quinolone is active against pseudomonas?
Ciprofloxacin
What are some common side effects of quinolones?
QT prolongation
Hearing impairment
Decreased appetite
Rhabdomylosis
Drug should be discontinued if psychiatric, neurological reactions occur
Cautioned in young adults and children- risk of arthropathy
What antibiotic would you use for PCP prophylaxis and treatment?
Co-trimoxazole
What is a rare but serious side effect of co-trimoxazole?
Blood disorders
Rash - steven johnson’s syndrome
What age group are tetracyclines contraindicated in?
Children < 12 due to deposition in growing bones and teeth
Staining of teeth can occur
What are the common side effects of tetracyclines?
Angiodema
Henoch Schonlein purpura (spotty rash)
Photosensitivity reaction
Headaches and visual disturbances- may indicate benign intercranial hypertension - discontinue if intercranial pressure increases
Is there any special patient advice with doxycycline?
Should be taken with meals
Avoid exposure to sunlight and sun lamps
Do not take zinc, indigestion remedies 2 hours before or after
What is a serious side effect of chloramphenicol when given systemically?
Haemotological side effects (agranulocytosos, bone marrow disorder)
Aplastic anaemia- reports of leukaemia
Should only be reserved for life-threatening conditions e.g. typhoid fever
What muscle side effect can daptomycin cause?
Myopathy
Report any muscle weakness and monitor creatine kinase if necessary
Need to monitor CK twice a week whilst on it
What monitoring requirements are needed for systemic fusidic acid?
Elevated liver enzymes, hyperbilirubinaemia and jaundice can occur with systemic use
Manufacturer advises monitor liver function with high doses or on prolonged therapy
What is the important safety information regarding linezolid?
Severe optic neuropathy- patients should report visual impairment
Blood disorders - thrombocytopenia, anaemia,
What food does linezolid interact with and why?
Tyramine-rich foods (such as mature cheese, salami)
Avoid consuming large amounts
Also is a reversible MAOI
Is linezolid active against gram-ve, gram+ve or both?
Gram +ve
What would be the dose of trimethoprim in an adult for UTI?
200mg BD
Can you use trimethoprim in renal impairment?
Yes- monitor
May need to half normal dose
What is the patient advice surrounding rifampicin?
May stain contact lenses red
Report signs of liver disorder
May colour urine red - harmless
How does rifampicin interact with hormonal contraceptives?
Effectiveness of hormonal contraceptives are reduced - alternative method needed
What antibiotics are used in the initial phase of TB treatment?
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
Streptomycin- hardly used but may be useful if resistant to isoniazid
How many antibacterials are used in the initial phase of TB treatment and how long for?
4
2 months